ul universidade de lisboa centro de fÍsica nuclear people: senior researchers (responsible for...

UL UNIVERSIDADE DE LISBOA

CENTRO DE FÍSICA NUCLEAR

People:

Senior Researchers (responsible for activity lines):

Eduardo Alves (Head of Lab)

Adelaide Pedro de Jesus

Luís Cerqueira Alves

Miguel Reis

Nuno Barradas

Rui Coelho da Silva

Teresa Pinheiro

Ulrich Wahl

ITN/CFNUL Ion Beam Laboratory

http://cfnul.cii.fc.ul.pt/

http://www.itn.pt/

IAEA Consultant Meeting, Wien 1-2 March 2010







ITN/CFNUL Ion Beam Laboratory

Van de Graaff 2.5 MV

DanFisik Implanter 210 kV

General Ionex Cockroft-Walton tandetron 3 MV



Van de Graaff

2.5 MV, 10 A (protons); H, He ions

Lines:

PIXE/Nuclear Reactions

RBS, Chan, ERDA

- probe

PIXE analysis of environmental, biomedical, material science, geological, art,….. samples

Nuclear Reactions for astrophysicsDevelopment of a PIGE methodology

Advanced Materials:Wide bandgap semiconductors and oxides Nuclear fusion reactor materials and mineralogical samples. Multiple quantum wells and quantum dots.

Materials ScienceBiomedicineEnvironmentArchaeometry and ArtMineralogy




General Ionex Cockroft-Walton tandetron 3MV

NEC Alphatros ion source for He beams Negative ion direct-extraction Duoplasmatron ion

source for H- beams. HICONEX Cs beam multielement negative ion

source




15 eV resolution (Transition Edge Superconductor -TES) detector

Tandem new lines of activity

Molecular speciation from PIXE spectra

Heavy Ion Elastic Recoil Detection analyses (HIERDA) – A ToF system is under construction to profile light ions using either Cl or I beams.


Two beamlines for AMS:

A) for 14C dating: 2 off-center Faraday cups for parallel current measurement

of 12C3+ and 13C3+, while the 14C3+ detection is by means of an electrostatic

analyzer and a gas proportional counter.

B) Heavy ion ("AUSTRALIS") beamline with HICONEX Cs microbeam (30-300 mm) multielement ("AUSTRALIS") negative ion source. The magnet is able of analyzing 6+ (or higher charge state) ions of all elements up to U at 2.5 MV terminal voltage.Sequential analysis of different isotopes (around +-3% of center mass) in the magnet is possible by means of the "fast bouncing" technique.




AMS





Nuclear Reactions/PIGE





Nuclear Reactions/PIGE


Beam

X-ray detectorG

amm

a-ra

y de

tect

or

Particle detectors



Development of a PIGE Methodology


DEPTH

Division of the sample surface in sublayers

YkYkYj

Yj

ERYA CODE

Within each sublayer the stopping power cross sections may be assumed as constant

SAMPLE

PROTON

DEPTH

YmYmYn

Yn YlYl Yi

Yi

Eincident=2380 keV

EincidentE-ΔE

Yield calculated by ERYA





Ei=2380 keVEi=2380 keV

ZOOMZOOM

Excitation function of 25Mg(p,p’)25Mg

Energy (keV)

(E)

arb

itra

ry u

nit

s

Thick targetEbeam=2380 to 0 keV

Thick targetEbeam=2380 to 0 keV

ERYA CODE





(E)k=5(E)k=5(E)k=6(E)k=6(E)k=4(E)k=4

Energy (keV)

(E)

arb

itra

ry u

nit

s to (E=0)to (E=0)

Number of sublayers is chosen equal to the number of energy steps in the excitation function

Number of sublayers is chosen equal to the number of energy steps in the excitation function

(E)k=3(E)k=3(E)k=2(E)k=2(E)k=1(E)k=1

ERYA CODE





The ERYA code - Labview

ERYA CODE





Aready accomplished

Li, B, F, Na; Mg, Al for proton energy up to 2.4 MeV

Be for proton energy up to 1.7 MeV

Li, F, Mg for energies up to 4 MeVAnalysis

going on

Work Done





Now and near future

The CNO problemGamma-ray spectrum of graphite at 1700 KeV

1

10

100

1000

10000

100000

0 500 1000 1500 2000 2500

Channel Number

Arb

itra

ry U

nit

s

Gamma-ray spectrum of graphite at 3950 keV

1

10

100

1000

10000

100000

0 500 1000 1500 2000 2500

Channel number

Arb

itra

ry U

nit

s

2.36 MeV

12C

2.36 MeV

12C





Now and near future

The CNO problem

Near future: Cross Section Measurement of (p, p´) and (p,) reactions on 15N and 18 O

Gamma-ray specrum of AgNO3 at 3950 KeV

1

10

100

1000

10000

100000

0 500 1000 1500 2000 2500 3000

Channel Number

Arb

itra

ry u

nit

s 4.44 MeV

15N

1.98 MeV

18O





The future

Inclusion of profiling in ERYA

Extension of other excitation functions to higher energies – 4 MeV

Coincidence methods to clean up the spectra

Special problems – underground ?

ul universidade de lisboa centro de fÍsica nuclear people: senior researchers (responsible for...

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