vladimír wagner
DESCRIPTION
NEMEA-4 Workshop October 16-18, 2007 Prague, Czech Republic. Systematic studies of neutron s produced in the Pb/U assembly irradiated by relativistic protons and deuterons. Vladimír Wagner Nuclear physics institute of CAS, 250 68 Řež, Czech Republic, E_mail: [email protected] - PowerPoint PPT PresentationTRANSCRIPT
Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
Vladimiacuter Wagner
Nuclear physics institute of CAS 250 68 Řež Czech Republic E_mail wagnerujfcascz
for collaboration ldquoEnergy plus transmutationrdquo
(Russia Belarus Germany Greece Poland Ukraine Czech Republic hellip)
1 Introduction
2 Integral neutron production 21 Used method 22 Overview of lead target data 23 PbU assembly data
3 Spatial distribution of neutron field 41 Comparison between experiment and simulation 42 Possible sources of discrepancies
4 Conclusions and outlooks
NEMEA-4 Workshop October 16-18 2007 Prague Czech Republic
1) Understanding of sources of experimental data uncertainties ndash set of simulations of our set-up using MCNPX code
2) Set of proton experiments with different energies was completed and analyzed first two deuteron experiments were done
3) Systematic comparison of experimental data was done (integral neutron production and its spatial distribution) dependencies on beam energy were analyzed comparison with lead target results
4) Systematic comparison of experimental data with MCNPX simulations
Our main objectives Neutron distribution studies ndash radiation samples
Set-up Lead target diameter 84 cm length 48 cm Natural uranium blanket rods with Al cladding total weight 2064 kg Shielding box polyethylene with 1 mm Cd on the inside side
Energy plus Transmutation (EPT) Setup
Results
Proton systematic
Ep = 07 GeV
Ep = 10 GeV
Ep = 15 GeV
Ep = 20 GeV
Deuteron systematic
Ed = 252 GeV = 126 GeVnucleon
Ed = 16 GeV = 08 GeVnucleon
Experiments
Beam integral 06 ndash 341013 protons or deuterons irradiations - hours
Reactions with thresholds from 6 MeV up to 46 MeV
Spatial distribution of neutron field ( different threshold reactions)
Simulations
MCNPX code ndash Bertini CEM Isabel cascade model INCL4
Used versions MCNPX 26C
The homogenous field of neutrons with energy 1 eV ndash 01 MeV is produced inside container
Example of simulated (MCNPX) neutron spectra inside shielding container with set-up ldquoEnergy + transmutationrdquo(spectrum on the top of U blanket 11 cm from the front)
Container with polyethylene
size 100106111 cm3 weight 950 kg Cd layer at inner walls ndash 1 mm thickness
Reaction 197Au(nγ)198Au ndash only by moderated neutrons from container
Dependence mainly on integral number of neutrons escaping target blanket set-up
Moderation ndash many times scattered neutrons rarr direction information is loosed
Shielding box with polyethylene (the Cd layer is used for thermal neutrons absorption)
Small changes with position
near the center ndash the best situation
We use gold foils
Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)
00
02
04
06
08
10
12
0 10 20 30 40 50
Distance from the target front [cm]
Ex
pe
rim
en
tS
imu
lati
on
00
02
04
06
08
10
12
14
16
18
0 2 4 6 8 10
Foil number
Exp
erim
ent
Sim
ula
tio
ns
0E+00
1E-04
2E-04
3E-04
4E-04
5E-04
6E-04
7E-04
0 10 20 30 40 50Distance from the target front [cm]
Pro
du
ctio
n r
ates
per
pro
ton
an
d f
oil
g
ram
Gold foils - 198Au production inside polyethylene shielding
EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)
(determination of ratio between experimental and simulated data for different foils)
Determination of integral number of produced neutrons
Experimental integral neutron number = obtained ratio simulated integral number of neutrons
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200
Target thickness [cm]
neut
rons
per
pro
ton
05 GeV
1 GeV
15 GeV
2 GeV
25 GeV
3 GeV
35 GeV
4 GeV
45 GeV
5 GeV
050
100150200250300350400
0 1 2 3 4 5 6Proton energy [GeV]
Ioni
satio
n ra
nge
[cm
]
Neutron production on lead target ndash dependency on target sizes
R = 5 cm
L = 50 cm E = 1 GeV
0
5
10
15
20
25
30
35
0 10 20 30 40 50 60Radius [cm]
neu
tro
ns
per
pro
ton
Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions
Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm
(MCNPX simulations)
σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
Proton energy [GeV]
Ne
utr
on
s p
er
pro
ton R=5 cm L=100 cm
R=50 cm L=100 cm
Systematization of experimental data for lead target
Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)
Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production
Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)
Dependency of integral neutron number on beam energy
Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX
SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120
R = 5 cm L = 100 cm
0
10
20
30
40
50
60
0 1 2 3Proton Energy [GeV]
Neu
tro
ns
per
pro
ton
D West E Wood
JS Fraser et al
RG Vasilkov et al 1
RG Vasilkov et al 2
MSZucker et al
our
MA Lone et al
D Hilscher et al
K van der Meer et al
B Lott et al
YuVRyabov et al
A Letourneau et al
MCNPX Simulations
Experimenal data fit
Our simple lead target result
EPT set-up ndash lead plus uranium
U-target (radius=50cm length=150cm)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Proton energy [GeV]
Nu
mb
er o
f n
eutr
on
s escape
capture
total
U-target (radius=optimal length=optimal)
0
50
100
150
200
250
0 1 2 3 4 5 6
Proton energy [MeV]
Num
ber o
f neu
tron
s
escape
Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm
15 GeV
0
10
20
30
40
50
60
70
80
0 50 100 150
target thickness [cm]
neu
tro
ns
per
pro
ton
5
10
15
20
25
30
35
40
45
50
Strong influence of neutron capture
For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
1) Understanding of sources of experimental data uncertainties ndash set of simulations of our set-up using MCNPX code
2) Set of proton experiments with different energies was completed and analyzed first two deuteron experiments were done
3) Systematic comparison of experimental data was done (integral neutron production and its spatial distribution) dependencies on beam energy were analyzed comparison with lead target results
4) Systematic comparison of experimental data with MCNPX simulations
Our main objectives Neutron distribution studies ndash radiation samples
Set-up Lead target diameter 84 cm length 48 cm Natural uranium blanket rods with Al cladding total weight 2064 kg Shielding box polyethylene with 1 mm Cd on the inside side
Energy plus Transmutation (EPT) Setup
Results
Proton systematic
Ep = 07 GeV
Ep = 10 GeV
Ep = 15 GeV
Ep = 20 GeV
Deuteron systematic
Ed = 252 GeV = 126 GeVnucleon
Ed = 16 GeV = 08 GeVnucleon
Experiments
Beam integral 06 ndash 341013 protons or deuterons irradiations - hours
Reactions with thresholds from 6 MeV up to 46 MeV
Spatial distribution of neutron field ( different threshold reactions)
Simulations
MCNPX code ndash Bertini CEM Isabel cascade model INCL4
Used versions MCNPX 26C
The homogenous field of neutrons with energy 1 eV ndash 01 MeV is produced inside container
Example of simulated (MCNPX) neutron spectra inside shielding container with set-up ldquoEnergy + transmutationrdquo(spectrum on the top of U blanket 11 cm from the front)
Container with polyethylene
size 100106111 cm3 weight 950 kg Cd layer at inner walls ndash 1 mm thickness
Reaction 197Au(nγ)198Au ndash only by moderated neutrons from container
Dependence mainly on integral number of neutrons escaping target blanket set-up
Moderation ndash many times scattered neutrons rarr direction information is loosed
Shielding box with polyethylene (the Cd layer is used for thermal neutrons absorption)
Small changes with position
near the center ndash the best situation
We use gold foils
Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)
00
02
04
06
08
10
12
0 10 20 30 40 50
Distance from the target front [cm]
Ex
pe
rim
en
tS
imu
lati
on
00
02
04
06
08
10
12
14
16
18
0 2 4 6 8 10
Foil number
Exp
erim
ent
Sim
ula
tio
ns
0E+00
1E-04
2E-04
3E-04
4E-04
5E-04
6E-04
7E-04
0 10 20 30 40 50Distance from the target front [cm]
Pro
du
ctio
n r
ates
per
pro
ton
an
d f
oil
g
ram
Gold foils - 198Au production inside polyethylene shielding
EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)
(determination of ratio between experimental and simulated data for different foils)
Determination of integral number of produced neutrons
Experimental integral neutron number = obtained ratio simulated integral number of neutrons
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200
Target thickness [cm]
neut
rons
per
pro
ton
05 GeV
1 GeV
15 GeV
2 GeV
25 GeV
3 GeV
35 GeV
4 GeV
45 GeV
5 GeV
050
100150200250300350400
0 1 2 3 4 5 6Proton energy [GeV]
Ioni
satio
n ra
nge
[cm
]
Neutron production on lead target ndash dependency on target sizes
R = 5 cm
L = 50 cm E = 1 GeV
0
5
10
15
20
25
30
35
0 10 20 30 40 50 60Radius [cm]
neu
tro
ns
per
pro
ton
Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions
Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm
(MCNPX simulations)
σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
Proton energy [GeV]
Ne
utr
on
s p
er
pro
ton R=5 cm L=100 cm
R=50 cm L=100 cm
Systematization of experimental data for lead target
Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)
Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production
Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)
Dependency of integral neutron number on beam energy
Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX
SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120
R = 5 cm L = 100 cm
0
10
20
30
40
50
60
0 1 2 3Proton Energy [GeV]
Neu
tro
ns
per
pro
ton
D West E Wood
JS Fraser et al
RG Vasilkov et al 1
RG Vasilkov et al 2
MSZucker et al
our
MA Lone et al
D Hilscher et al
K van der Meer et al
B Lott et al
YuVRyabov et al
A Letourneau et al
MCNPX Simulations
Experimenal data fit
Our simple lead target result
EPT set-up ndash lead plus uranium
U-target (radius=50cm length=150cm)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Proton energy [GeV]
Nu
mb
er o
f n
eutr
on
s escape
capture
total
U-target (radius=optimal length=optimal)
0
50
100
150
200
250
0 1 2 3 4 5 6
Proton energy [MeV]
Num
ber o
f neu
tron
s
escape
Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm
15 GeV
0
10
20
30
40
50
60
70
80
0 50 100 150
target thickness [cm]
neu
tro
ns
per
pro
ton
5
10
15
20
25
30
35
40
45
50
Strong influence of neutron capture
For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
Proton systematic
Ep = 07 GeV
Ep = 10 GeV
Ep = 15 GeV
Ep = 20 GeV
Deuteron systematic
Ed = 252 GeV = 126 GeVnucleon
Ed = 16 GeV = 08 GeVnucleon
Experiments
Beam integral 06 ndash 341013 protons or deuterons irradiations - hours
Reactions with thresholds from 6 MeV up to 46 MeV
Spatial distribution of neutron field ( different threshold reactions)
Simulations
MCNPX code ndash Bertini CEM Isabel cascade model INCL4
Used versions MCNPX 26C
The homogenous field of neutrons with energy 1 eV ndash 01 MeV is produced inside container
Example of simulated (MCNPX) neutron spectra inside shielding container with set-up ldquoEnergy + transmutationrdquo(spectrum on the top of U blanket 11 cm from the front)
Container with polyethylene
size 100106111 cm3 weight 950 kg Cd layer at inner walls ndash 1 mm thickness
Reaction 197Au(nγ)198Au ndash only by moderated neutrons from container
Dependence mainly on integral number of neutrons escaping target blanket set-up
Moderation ndash many times scattered neutrons rarr direction information is loosed
Shielding box with polyethylene (the Cd layer is used for thermal neutrons absorption)
Small changes with position
near the center ndash the best situation
We use gold foils
Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)
00
02
04
06
08
10
12
0 10 20 30 40 50
Distance from the target front [cm]
Ex
pe
rim
en
tS
imu
lati
on
00
02
04
06
08
10
12
14
16
18
0 2 4 6 8 10
Foil number
Exp
erim
ent
Sim
ula
tio
ns
0E+00
1E-04
2E-04
3E-04
4E-04
5E-04
6E-04
7E-04
0 10 20 30 40 50Distance from the target front [cm]
Pro
du
ctio
n r
ates
per
pro
ton
an
d f
oil
g
ram
Gold foils - 198Au production inside polyethylene shielding
EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)
(determination of ratio between experimental and simulated data for different foils)
Determination of integral number of produced neutrons
Experimental integral neutron number = obtained ratio simulated integral number of neutrons
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200
Target thickness [cm]
neut
rons
per
pro
ton
05 GeV
1 GeV
15 GeV
2 GeV
25 GeV
3 GeV
35 GeV
4 GeV
45 GeV
5 GeV
050
100150200250300350400
0 1 2 3 4 5 6Proton energy [GeV]
Ioni
satio
n ra
nge
[cm
]
Neutron production on lead target ndash dependency on target sizes
R = 5 cm
L = 50 cm E = 1 GeV
0
5
10
15
20
25
30
35
0 10 20 30 40 50 60Radius [cm]
neu
tro
ns
per
pro
ton
Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions
Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm
(MCNPX simulations)
σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
Proton energy [GeV]
Ne
utr
on
s p
er
pro
ton R=5 cm L=100 cm
R=50 cm L=100 cm
Systematization of experimental data for lead target
Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)
Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production
Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)
Dependency of integral neutron number on beam energy
Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX
SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120
R = 5 cm L = 100 cm
0
10
20
30
40
50
60
0 1 2 3Proton Energy [GeV]
Neu
tro
ns
per
pro
ton
D West E Wood
JS Fraser et al
RG Vasilkov et al 1
RG Vasilkov et al 2
MSZucker et al
our
MA Lone et al
D Hilscher et al
K van der Meer et al
B Lott et al
YuVRyabov et al
A Letourneau et al
MCNPX Simulations
Experimenal data fit
Our simple lead target result
EPT set-up ndash lead plus uranium
U-target (radius=50cm length=150cm)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Proton energy [GeV]
Nu
mb
er o
f n
eutr
on
s escape
capture
total
U-target (radius=optimal length=optimal)
0
50
100
150
200
250
0 1 2 3 4 5 6
Proton energy [MeV]
Num
ber o
f neu
tron
s
escape
Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm
15 GeV
0
10
20
30
40
50
60
70
80
0 50 100 150
target thickness [cm]
neu
tro
ns
per
pro
ton
5
10
15
20
25
30
35
40
45
50
Strong influence of neutron capture
For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
The homogenous field of neutrons with energy 1 eV ndash 01 MeV is produced inside container
Example of simulated (MCNPX) neutron spectra inside shielding container with set-up ldquoEnergy + transmutationrdquo(spectrum on the top of U blanket 11 cm from the front)
Container with polyethylene
size 100106111 cm3 weight 950 kg Cd layer at inner walls ndash 1 mm thickness
Reaction 197Au(nγ)198Au ndash only by moderated neutrons from container
Dependence mainly on integral number of neutrons escaping target blanket set-up
Moderation ndash many times scattered neutrons rarr direction information is loosed
Shielding box with polyethylene (the Cd layer is used for thermal neutrons absorption)
Small changes with position
near the center ndash the best situation
We use gold foils
Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)
00
02
04
06
08
10
12
0 10 20 30 40 50
Distance from the target front [cm]
Ex
pe
rim
en
tS
imu
lati
on
00
02
04
06
08
10
12
14
16
18
0 2 4 6 8 10
Foil number
Exp
erim
ent
Sim
ula
tio
ns
0E+00
1E-04
2E-04
3E-04
4E-04
5E-04
6E-04
7E-04
0 10 20 30 40 50Distance from the target front [cm]
Pro
du
ctio
n r
ates
per
pro
ton
an
d f
oil
g
ram
Gold foils - 198Au production inside polyethylene shielding
EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)
(determination of ratio between experimental and simulated data for different foils)
Determination of integral number of produced neutrons
Experimental integral neutron number = obtained ratio simulated integral number of neutrons
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200
Target thickness [cm]
neut
rons
per
pro
ton
05 GeV
1 GeV
15 GeV
2 GeV
25 GeV
3 GeV
35 GeV
4 GeV
45 GeV
5 GeV
050
100150200250300350400
0 1 2 3 4 5 6Proton energy [GeV]
Ioni
satio
n ra
nge
[cm
]
Neutron production on lead target ndash dependency on target sizes
R = 5 cm
L = 50 cm E = 1 GeV
0
5
10
15
20
25
30
35
0 10 20 30 40 50 60Radius [cm]
neu
tro
ns
per
pro
ton
Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions
Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm
(MCNPX simulations)
σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
Proton energy [GeV]
Ne
utr
on
s p
er
pro
ton R=5 cm L=100 cm
R=50 cm L=100 cm
Systematization of experimental data for lead target
Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)
Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production
Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)
Dependency of integral neutron number on beam energy
Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX
SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120
R = 5 cm L = 100 cm
0
10
20
30
40
50
60
0 1 2 3Proton Energy [GeV]
Neu
tro
ns
per
pro
ton
D West E Wood
JS Fraser et al
RG Vasilkov et al 1
RG Vasilkov et al 2
MSZucker et al
our
MA Lone et al
D Hilscher et al
K van der Meer et al
B Lott et al
YuVRyabov et al
A Letourneau et al
MCNPX Simulations
Experimenal data fit
Our simple lead target result
EPT set-up ndash lead plus uranium
U-target (radius=50cm length=150cm)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Proton energy [GeV]
Nu
mb
er o
f n
eutr
on
s escape
capture
total
U-target (radius=optimal length=optimal)
0
50
100
150
200
250
0 1 2 3 4 5 6
Proton energy [MeV]
Num
ber o
f neu
tron
s
escape
Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm
15 GeV
0
10
20
30
40
50
60
70
80
0 50 100 150
target thickness [cm]
neu
tro
ns
per
pro
ton
5
10
15
20
25
30
35
40
45
50
Strong influence of neutron capture
For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
Small changes with position
near the center ndash the best situation
We use gold foils
Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)
00
02
04
06
08
10
12
0 10 20 30 40 50
Distance from the target front [cm]
Ex
pe
rim
en
tS
imu
lati
on
00
02
04
06
08
10
12
14
16
18
0 2 4 6 8 10
Foil number
Exp
erim
ent
Sim
ula
tio
ns
0E+00
1E-04
2E-04
3E-04
4E-04
5E-04
6E-04
7E-04
0 10 20 30 40 50Distance from the target front [cm]
Pro
du
ctio
n r
ates
per
pro
ton
an
d f
oil
g
ram
Gold foils - 198Au production inside polyethylene shielding
EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)
(determination of ratio between experimental and simulated data for different foils)
Determination of integral number of produced neutrons
Experimental integral neutron number = obtained ratio simulated integral number of neutrons
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200
Target thickness [cm]
neut
rons
per
pro
ton
05 GeV
1 GeV
15 GeV
2 GeV
25 GeV
3 GeV
35 GeV
4 GeV
45 GeV
5 GeV
050
100150200250300350400
0 1 2 3 4 5 6Proton energy [GeV]
Ioni
satio
n ra
nge
[cm
]
Neutron production on lead target ndash dependency on target sizes
R = 5 cm
L = 50 cm E = 1 GeV
0
5
10
15
20
25
30
35
0 10 20 30 40 50 60Radius [cm]
neu
tro
ns
per
pro
ton
Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions
Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm
(MCNPX simulations)
σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
Proton energy [GeV]
Ne
utr
on
s p
er
pro
ton R=5 cm L=100 cm
R=50 cm L=100 cm
Systematization of experimental data for lead target
Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)
Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production
Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)
Dependency of integral neutron number on beam energy
Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX
SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120
R = 5 cm L = 100 cm
0
10
20
30
40
50
60
0 1 2 3Proton Energy [GeV]
Neu
tro
ns
per
pro
ton
D West E Wood
JS Fraser et al
RG Vasilkov et al 1
RG Vasilkov et al 2
MSZucker et al
our
MA Lone et al
D Hilscher et al
K van der Meer et al
B Lott et al
YuVRyabov et al
A Letourneau et al
MCNPX Simulations
Experimenal data fit
Our simple lead target result
EPT set-up ndash lead plus uranium
U-target (radius=50cm length=150cm)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Proton energy [GeV]
Nu
mb
er o
f n
eutr
on
s escape
capture
total
U-target (radius=optimal length=optimal)
0
50
100
150
200
250
0 1 2 3 4 5 6
Proton energy [MeV]
Num
ber o
f neu
tron
s
escape
Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm
15 GeV
0
10
20
30
40
50
60
70
80
0 50 100 150
target thickness [cm]
neu
tro
ns
per
pro
ton
5
10
15
20
25
30
35
40
45
50
Strong influence of neutron capture
For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200
Target thickness [cm]
neut
rons
per
pro
ton
05 GeV
1 GeV
15 GeV
2 GeV
25 GeV
3 GeV
35 GeV
4 GeV
45 GeV
5 GeV
050
100150200250300350400
0 1 2 3 4 5 6Proton energy [GeV]
Ioni
satio
n ra
nge
[cm
]
Neutron production on lead target ndash dependency on target sizes
R = 5 cm
L = 50 cm E = 1 GeV
0
5
10
15
20
25
30
35
0 10 20 30 40 50 60Radius [cm]
neu
tro
ns
per
pro
ton
Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions
Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm
(MCNPX simulations)
σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
Proton energy [GeV]
Ne
utr
on
s p
er
pro
ton R=5 cm L=100 cm
R=50 cm L=100 cm
Systematization of experimental data for lead target
Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)
Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production
Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)
Dependency of integral neutron number on beam energy
Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX
SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120
R = 5 cm L = 100 cm
0
10
20
30
40
50
60
0 1 2 3Proton Energy [GeV]
Neu
tro
ns
per
pro
ton
D West E Wood
JS Fraser et al
RG Vasilkov et al 1
RG Vasilkov et al 2
MSZucker et al
our
MA Lone et al
D Hilscher et al
K van der Meer et al
B Lott et al
YuVRyabov et al
A Letourneau et al
MCNPX Simulations
Experimenal data fit
Our simple lead target result
EPT set-up ndash lead plus uranium
U-target (radius=50cm length=150cm)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Proton energy [GeV]
Nu
mb
er o
f n
eutr
on
s escape
capture
total
U-target (radius=optimal length=optimal)
0
50
100
150
200
250
0 1 2 3 4 5 6
Proton energy [MeV]
Num
ber o
f neu
tron
s
escape
Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm
15 GeV
0
10
20
30
40
50
60
70
80
0 50 100 150
target thickness [cm]
neu
tro
ns
per
pro
ton
5
10
15
20
25
30
35
40
45
50
Strong influence of neutron capture
For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
Proton energy [GeV]
Ne
utr
on
s p
er
pro
ton R=5 cm L=100 cm
R=50 cm L=100 cm
Systematization of experimental data for lead target
Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)
Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production
Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)
Dependency of integral neutron number on beam energy
Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX
SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120
R = 5 cm L = 100 cm
0
10
20
30
40
50
60
0 1 2 3Proton Energy [GeV]
Neu
tro
ns
per
pro
ton
D West E Wood
JS Fraser et al
RG Vasilkov et al 1
RG Vasilkov et al 2
MSZucker et al
our
MA Lone et al
D Hilscher et al
K van der Meer et al
B Lott et al
YuVRyabov et al
A Letourneau et al
MCNPX Simulations
Experimenal data fit
Our simple lead target result
EPT set-up ndash lead plus uranium
U-target (radius=50cm length=150cm)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Proton energy [GeV]
Nu
mb
er o
f n
eutr
on
s escape
capture
total
U-target (radius=optimal length=optimal)
0
50
100
150
200
250
0 1 2 3 4 5 6
Proton energy [MeV]
Num
ber o
f neu
tron
s
escape
Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm
15 GeV
0
10
20
30
40
50
60
70
80
0 50 100 150
target thickness [cm]
neu
tro
ns
per
pro
ton
5
10
15
20
25
30
35
40
45
50
Strong influence of neutron capture
For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
Dependency of integral neutron number on beam energy
Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX
SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120
R = 5 cm L = 100 cm
0
10
20
30
40
50
60
0 1 2 3Proton Energy [GeV]
Neu
tro
ns
per
pro
ton
D West E Wood
JS Fraser et al
RG Vasilkov et al 1
RG Vasilkov et al 2
MSZucker et al
our
MA Lone et al
D Hilscher et al
K van der Meer et al
B Lott et al
YuVRyabov et al
A Letourneau et al
MCNPX Simulations
Experimenal data fit
Our simple lead target result
EPT set-up ndash lead plus uranium
U-target (radius=50cm length=150cm)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Proton energy [GeV]
Nu
mb
er o
f n
eutr
on
s escape
capture
total
U-target (radius=optimal length=optimal)
0
50
100
150
200
250
0 1 2 3 4 5 6
Proton energy [MeV]
Num
ber o
f neu
tron
s
escape
Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm
15 GeV
0
10
20
30
40
50
60
70
80
0 50 100 150
target thickness [cm]
neu
tro
ns
per
pro
ton
5
10
15
20
25
30
35
40
45
50
Strong influence of neutron capture
For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
EPT set-up ndash lead plus uranium
U-target (radius=50cm length=150cm)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Proton energy [GeV]
Nu
mb
er o
f n
eutr
on
s escape
capture
total
U-target (radius=optimal length=optimal)
0
50
100
150
200
250
0 1 2 3 4 5 6
Proton energy [MeV]
Num
ber o
f neu
tron
s
escape
Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm
15 GeV
0
10
20
30
40
50
60
70
80
0 50 100 150
target thickness [cm]
neu
tro
ns
per
pro
ton
5
10
15
20
25
30
35
40
45
50
Strong influence of neutron capture
For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
EPT set-up ndash dependency of integral neutron number on beam energy
Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)
More or less good description of integral neutron production by MCNPX simulation
Beam energynucleon Beam energy per particle
0
10
20
30
40
50
60
70
80
90
0 05 1 15 2 25 3
Beam energy [GeV]
Ne
utr
on
s p
er
pro
ton
Only lead target
EPT experiment -protons
EPT experiment -deuterons
EPT simulation -protons
EPT simulation -deuterons
Pb maximal
Uranium
Pb target -experimental
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV
Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
0
10
20
30
40
50
60
0 1 2 3
Beam energy [GeV]
neu
tro
ns
per
1 G
eV Protons - experiment
Protons - simulation
Deuterons - experiment
Deuterons - simulation
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
00
05
10
15
20
25
0 5 10 15Radial distance from target axis [cm]
ex
p
yie
ld
sim
y
ield
20 GeV
15 GeV
10 GeV
07 GeV
High energy neutrons ndash threshold neutron reactions
We see clear dependence of MCNPX description quality on beam energy
Normalized to this foils
197Au(n4n)194Au ETHR=245 MeV
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
1
15
2
25
3
35
4
45
1 10 100 1000
Neutron energy [MeV]
1 GeV 07 GeV
15 GeV 07 GeV
20 GeV 07 GeV
1E-4
1E-3
1E-2
1E-1
1E+0 1E+1 1E+2 1E+3 1E+4
Neutron Energy [MeV]
Nu
mb
er o
f n
eutr
on
s
07 GeV
1 GeV
15 GeV
2 GeV
Neutron energy spectra for different beam energy
(longitudinal distance radial distance 3 cm)
Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV
Possible source of experiment simulation differences
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
Conclusions and outlooks
bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments
bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container
bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination
bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target
bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy
bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month
bull Experiments collected nice set of data for systematic benchmark comparison
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-
The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala
Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all
We use activation foils from Au Bi In and Ta
Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)
measurements of cross-sections of (nxn)-reactions (with x up to 9)
The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV
Proposal was sent to EFNUDAT PAC for October meeting
- Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Conclusions and outlooks
- Slide 14
-