1
Measurement of excitation yields of low energy prompt -ray from proton bombardment of 48Ti foil
VN Bondarenko AV Goncharov a IM Karnaukhov VI Sukhostavets A G Tolstolutskiy SN Utenkov KV Shebeko
NSC KIPT Kharkov Ukraine
1-st Technical Meeting on Development of Reference Database for Particle-Induced Ray Emission (PIGE) Spectroscopy 16-20 May 2011 IAEA Headquarters Vienna
National Scientific Centre National Scientific Centre Kharkov Institute of Physics and TechnologyKharkov Institute of Physics and Technology
a Chief scientific investigator
2
Kharkov on a map
3
Kharkov Institute of Physics and Technology
1928 ndash founded with aim of developing urgent fields of research 1931 ndash the cryogenic laboratory first in the USSR was organized 1932 ndash 1937 Landau formed an internationally known school of
theoretical physics 1934 ndash the first in the world radar was constructed 1937 ndash Van de Graaff accelerator (25 MeV) first in the USSR was built Post-war years ndash activity in the field of atomic energy including
investigations of thermonuclear fusion 1960-1970 ndash many unique experimental facilities namely a number of
electron and ion accelerators including the largest in the USSR electron linear accelerator were built
1972 ndash 1991 the Institute executed functions of a main organization in the USSR in the field of radiation materials science and radiation technologies
1991 - present time ndash the Institute constitutes an essential part of research complex of Ukraine especially in the field of atomic industry material science accelerator equipment and new sources of energy for civil and defense purposes
4
The basic fields of research work at NSC KIPT
Solid-state physics Physics of radiation effects and radiation materials science Technologies of materials
Plasma physics and controlled fusion Nuclear physics physics of electromagnetic
interactions physics and engineering of electron accelerators
Plasma electronics and physics of high-current beams Physics and engineering of heavy charged particle accelerators New methods of acceleration
Theoretical physics
5
The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels
That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database
Motivation
6
- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+
NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator
7
RF source of gas ions H+ He+ N+
NSC KIPT ldquoSokolrdquo Van de Graaff accelerator
- Acceleration voltage 02 hellip 2 МeV - Energy spread 007
- Ion beam current of the direct output 50 μА
- Ion beam current after the bending magnet 10 μА
8
Experimental beam lines of the
ldquoSOKOLrdquo facility
1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE
ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm
1 2
3
4
5
6
7
9
Experimental setup for low energy -emission measurements
Experimental chamber with100 m Be-window
HPGe detector (20 mm26 mm)
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
2
Kharkov on a map
3
Kharkov Institute of Physics and Technology
1928 ndash founded with aim of developing urgent fields of research 1931 ndash the cryogenic laboratory first in the USSR was organized 1932 ndash 1937 Landau formed an internationally known school of
theoretical physics 1934 ndash the first in the world radar was constructed 1937 ndash Van de Graaff accelerator (25 MeV) first in the USSR was built Post-war years ndash activity in the field of atomic energy including
investigations of thermonuclear fusion 1960-1970 ndash many unique experimental facilities namely a number of
electron and ion accelerators including the largest in the USSR electron linear accelerator were built
1972 ndash 1991 the Institute executed functions of a main organization in the USSR in the field of radiation materials science and radiation technologies
1991 - present time ndash the Institute constitutes an essential part of research complex of Ukraine especially in the field of atomic industry material science accelerator equipment and new sources of energy for civil and defense purposes
4
The basic fields of research work at NSC KIPT
Solid-state physics Physics of radiation effects and radiation materials science Technologies of materials
Plasma physics and controlled fusion Nuclear physics physics of electromagnetic
interactions physics and engineering of electron accelerators
Plasma electronics and physics of high-current beams Physics and engineering of heavy charged particle accelerators New methods of acceleration
Theoretical physics
5
The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels
That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database
Motivation
6
- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+
NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator
7
RF source of gas ions H+ He+ N+
NSC KIPT ldquoSokolrdquo Van de Graaff accelerator
- Acceleration voltage 02 hellip 2 МeV - Energy spread 007
- Ion beam current of the direct output 50 μА
- Ion beam current after the bending magnet 10 μА
8
Experimental beam lines of the
ldquoSOKOLrdquo facility
1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE
ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm
1 2
3
4
5
6
7
9
Experimental setup for low energy -emission measurements
Experimental chamber with100 m Be-window
HPGe detector (20 mm26 mm)
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
3
Kharkov Institute of Physics and Technology
1928 ndash founded with aim of developing urgent fields of research 1931 ndash the cryogenic laboratory first in the USSR was organized 1932 ndash 1937 Landau formed an internationally known school of
theoretical physics 1934 ndash the first in the world radar was constructed 1937 ndash Van de Graaff accelerator (25 MeV) first in the USSR was built Post-war years ndash activity in the field of atomic energy including
investigations of thermonuclear fusion 1960-1970 ndash many unique experimental facilities namely a number of
electron and ion accelerators including the largest in the USSR electron linear accelerator were built
1972 ndash 1991 the Institute executed functions of a main organization in the USSR in the field of radiation materials science and radiation technologies
1991 - present time ndash the Institute constitutes an essential part of research complex of Ukraine especially in the field of atomic industry material science accelerator equipment and new sources of energy for civil and defense purposes
4
The basic fields of research work at NSC KIPT
Solid-state physics Physics of radiation effects and radiation materials science Technologies of materials
Plasma physics and controlled fusion Nuclear physics physics of electromagnetic
interactions physics and engineering of electron accelerators
Plasma electronics and physics of high-current beams Physics and engineering of heavy charged particle accelerators New methods of acceleration
Theoretical physics
5
The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels
That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database
Motivation
6
- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+
NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator
7
RF source of gas ions H+ He+ N+
NSC KIPT ldquoSokolrdquo Van de Graaff accelerator
- Acceleration voltage 02 hellip 2 МeV - Energy spread 007
- Ion beam current of the direct output 50 μА
- Ion beam current after the bending magnet 10 μА
8
Experimental beam lines of the
ldquoSOKOLrdquo facility
1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE
ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm
1 2
3
4
5
6
7
9
Experimental setup for low energy -emission measurements
Experimental chamber with100 m Be-window
HPGe detector (20 mm26 mm)
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
4
The basic fields of research work at NSC KIPT
Solid-state physics Physics of radiation effects and radiation materials science Technologies of materials
Plasma physics and controlled fusion Nuclear physics physics of electromagnetic
interactions physics and engineering of electron accelerators
Plasma electronics and physics of high-current beams Physics and engineering of heavy charged particle accelerators New methods of acceleration
Theoretical physics
5
The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels
That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database
Motivation
6
- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+
NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator
7
RF source of gas ions H+ He+ N+
NSC KIPT ldquoSokolrdquo Van de Graaff accelerator
- Acceleration voltage 02 hellip 2 МeV - Energy spread 007
- Ion beam current of the direct output 50 μА
- Ion beam current after the bending magnet 10 μА
8
Experimental beam lines of the
ldquoSOKOLrdquo facility
1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE
ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm
1 2
3
4
5
6
7
9
Experimental setup for low energy -emission measurements
Experimental chamber with100 m Be-window
HPGe detector (20 mm26 mm)
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
5
The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels
That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database
Motivation
6
- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+
NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator
7
RF source of gas ions H+ He+ N+
NSC KIPT ldquoSokolrdquo Van de Graaff accelerator
- Acceleration voltage 02 hellip 2 МeV - Energy spread 007
- Ion beam current of the direct output 50 μА
- Ion beam current after the bending magnet 10 μА
8
Experimental beam lines of the
ldquoSOKOLrdquo facility
1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE
ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm
1 2
3
4
5
6
7
9
Experimental setup for low energy -emission measurements
Experimental chamber with100 m Be-window
HPGe detector (20 mm26 mm)
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
6
- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+
NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator
7
RF source of gas ions H+ He+ N+
NSC KIPT ldquoSokolrdquo Van de Graaff accelerator
- Acceleration voltage 02 hellip 2 МeV - Energy spread 007
- Ion beam current of the direct output 50 μА
- Ion beam current after the bending magnet 10 μА
8
Experimental beam lines of the
ldquoSOKOLrdquo facility
1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE
ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm
1 2
3
4
5
6
7
9
Experimental setup for low energy -emission measurements
Experimental chamber with100 m Be-window
HPGe detector (20 mm26 mm)
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
7
RF source of gas ions H+ He+ N+
NSC KIPT ldquoSokolrdquo Van de Graaff accelerator
- Acceleration voltage 02 hellip 2 МeV - Energy spread 007
- Ion beam current of the direct output 50 μА
- Ion beam current after the bending magnet 10 μА
8
Experimental beam lines of the
ldquoSOKOLrdquo facility
1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE
ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm
1 2
3
4
5
6
7
9
Experimental setup for low energy -emission measurements
Experimental chamber with100 m Be-window
HPGe detector (20 mm26 mm)
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
8
Experimental beam lines of the
ldquoSOKOLrdquo facility
1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE
ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm
1 2
3
4
5
6
7
9
Experimental setup for low energy -emission measurements
Experimental chamber with100 m Be-window
HPGe detector (20 mm26 mm)
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
9
Experimental setup for low energy -emission measurements
Experimental chamber with100 m Be-window
HPGe detector (20 mm26 mm)
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
10
Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging
(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei
Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)
So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness
But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance
In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement
On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances
At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
11
Isotope composition of the used 48Ti target
46Ti 47Ti 48Ti 49Ti 50Ti
02 10 978 07 03
Na Mg Al Si Ca Cr Fe Ni Cu Pb
0005 0013 0007 0007 0013 0006 0005 0006 0005 00005
Impurities
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
12
Measurement of the target thickness by RBS technique
200 400 600 8000
1000
2000
3000
4000
5000
Ti
Ta Ta
E
TiTa model Ta
Cou
nts
Channel number
RBS spectra from Ta target and 48Ti target on Ta backing
E1
Ti Ta-backing
= 1700
t
kE0-E
He+ E0=16 MeV
Ta
= 1700
kE0
He+ E0=16 MeV
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
13
Treatment of the RBS spectrometry data
Kinematical factor of elastic scattering
2
22
1
sin1cos
kkTa
He
M
M MHe is 4He atom mass MTa is Ta atom mass
Correct value of the Ti target thickness from RBS spectrometry data was determined from
numerical solution of the system of two equations for E1 and t
t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5
978 48Ti
STi(E) is the stopping power (MeVcm2at) of He ion
in Ti substance vs ion energy E
1
0
0
1cos
kE
EkETi
E
ETi ES
dEtES
dEt
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
14
Beam-target-detector geometry at the excitation function measurement
= 450
Ti
Ta-backing
100 m Be - window
Proton beam
HPGe - detector
= 900-rays
Guard ring- 300 V
At the geometry -ray absorption in a backing has no influence on measurement results
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
15
Calibration of the γ-ray detection system efficiency ε(Eγ)
The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)
With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)
n(Eγ) is the quantum yield of used nuclide for the energy Eγ
(quantumdecay) A is the activity of the source (decays)
τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors
EEE crystalabsorber4 Ω is the solid angle of the detector
εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)
εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation
4
EE eε
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
16
Proton energy loss in the Ti target
The energy loss ΔEp was determined from numerical solution of the
equation
p
pp
E
EETip ES
dEt 0
0cos
t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy
The interval of energy averaging at cross-section measurement is equal to the ΔEp
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
17
1000 1500 2000 2500 30000
100
200
300
400
500
600
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
18
Data reduction
The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression
cosft
d
dkNN ep
Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the
target
Since 23010 cmb e
QN p
Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ
N
srb
d
d
e
cos
106021 17
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
19
900 1000 1100 1200 1300 1400 1500 1600 17000
2
4
6
8
10
12
14900 1000 1100 1200 1300 1400 1500 1600 1700
0
2
4
6
8
10
12
14
dd
bs
r
E=906 keV
Proton energy keV
E=623 keV
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
Differential cross-sections for the production of 623 and 906 keV -rays
from the reactions 48Ti(p)49V lab=900 (Preliminary results)
Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
20
Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured
Summary
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
21
Further steps
bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions
48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and
48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV
Measurement perspectives
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
22
1000 1500 2000 2500 3000 35000
100
200
300
400
500
600
1362 keV
Q=2000 CE
p=1050 keV
Target 48Ti Ta
KX Ta
KX Ta
15293 keV
623 keV
906 keV
Cou
nts
Channel number
lab
72-
52-
32-
49V0
90639
152928
906 keV
623 keV 1529 keV
The typical spectrum of low-energy -ray from the 48Ti target
23
Thanks for your attention
23
Thanks for your attention