anastasios lagoyannis tandem accelerator laboratory institute of nuclear physics
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Anastasios LagoyannisTandem Accelerator Laboratory
Institute of Nuclear PhysicsN.C.S.R. “Demokritos”
Recent Developments of the PIGE setup at the Recent Developments of the PIGE setup at the Tandem Accelerator Facility of N.C.S.R. “Demokritos”Tandem Accelerator Facility of N.C.S.R. “Demokritos”
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
OutlineOutline
The Tandem @ I.N.P.
General Considerations for PIGE
Target preparation and characterization
Charge measurement
Experimental Apparatus
Proposed measurements
Conclusions
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
The 5.5 MV VdG Tandem accelerator @ I.N.P.The 5.5 MV VdG Tandem accelerator @ I.N.P.
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Basic Experimental ToolsBasic Experimental Tools
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
General Considerations for PIGEGeneral Considerations for PIGE
Suitable Targets thin for resonances
thick for yield and validation
well characterized
Charge measurement Effective way of measuring the
current (cross checked if possible)
Experimental Apparatus High efficiency
Good resolution
Placed to appropriate angles
Analyzing Software
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Target PreparationTarget Preparation
Requirements Thin target i.e. Self – supported / Thin substrate
Chemical and Thermal stability
Electrical conductivity
Act as charge reference
Gold Tgt Carbon
Possible Solution
Stoichiometry ???
Thickness ???
BUT :
EvaporationResistiveElectron gun
Purchase
Evaporator @ I.N.P. Demokritos
Means of acquisition:
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Target CharacterizationTarget Characterization
X – Ray Fluorescence
Beam - less Using standards Unsuitable for Z < Al
Rutherford Back Scattering
Depth profiling Suitable for sandwich like targets Problematic for low Z
EBS and NRA
Depth profiling Depends on previous measurements Good for low Z
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Charge measurement ICharge measurement I
Traditional way(s)
Sophisticated Faraday cups
Suppression voltages (collimator and target)
Bending magnets
AlternativesSurface barrier detector at backward angles
Beam Chopper
Independent of the target
Use of the RBS technique with a heavy element on target
Downsides
Insulating targets
Change of beams’ charge
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Charge measurement IICharge measurement II
Beam Chopper
Periodic movement In/Out (programmable)
Wing: Thin Au layer on Al
A SSB detects the backscattered from Au
Coincidence signals for In/Out
No additional NIM modules
Needs calibration at the beginning
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Experimental apparatusExperimental apparatus
Electronically controlled turntable
Initial angles: 0o – 55o – 90o - 165o
4 HPGe detectors (1 – 80%, 3 – 100%)
2 Compton suppression BGO’s
Possibility of mounting backward Si detector
Possibility of mounting Si annular detector
Air / Water cooled target
NIM electronics
Singles Fast ADC DAQ
CAMAC event by event DAQ
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Experimental ProcedureExperimental Procedure
Preparation/characterization of the targets
Energy and Efficiency calibration of Ge detectors using point sources
Q x Ω calculation for the Si detector using RBS spectra from gold
Determination of Q using chopper and RBS technique
Machine calibration using either 27Al(p,γ) or threshold reactions
Peak analysis using two different algorithms to account for the bias error
Data validation using thick targets and appropriate software
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Proposed Measurement for Proposed Measurement for 3232SS
Experiment
Energy range : 3000 – 7000 keV
Steps: Varying (excitation function depending)Target: sandwich like Ta – TiS - Carbon C. Tsartsarakos et al. NIM B45 (1990), 33
Angle: 55o
Candidates:
32S(p,p’γ) 32S Εγ = 2230 keV
32S(d,pγ) 33S Εγ = 841 keV
32S(p, γ) 33S
Z. Elekes et al. NIM B168 (2000), 305
No PIGE related publications
C. Tsartsarakos et al. NIM B45 (1990), 33
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Candidates:
Proposed Measurement for Proposed Measurement for 1010B - B - 1111BB
10B(p,αγ) 7Be Εγ = 429 keV
10B(p,p’γ) 10B Εγ = 718 keV
R. Mateus et al. NIM B219 (2004), 519
V. Michaud et al. NIM B85 (1994), 881
C. Boni et al. NIM B35 (1988), 80 T. R. Ophel et al. Nucl. Phys. 33 (1962), 198
T. R. Ophel et al. Nucl. Phys. 33 (1962), 198
11B(p,γ) 12C Εγ = 11.68 MeV M. Koerdel et al. NIM B261 (2007), 520
11B(p,p’γ) 11B Εγ = 2125 MeV C. Boni et al. NIM B35 (1988), 80
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Proposed Measurement for Proposed Measurement for 1010B - B - 1111BB
C. Boni et al. NIM B35 (1988), 80 V. Michaud et al. NIM B85 (1994), 881
10B(p,αγ) 7Be
11B(p,p’γ) 11B
11B(p,p’γ) 11B
10B(p,p’γ) 10B
10B(p,αγ) 7Be
R. Mateus et al. NIM B219 (2004), 519
Experiment
Energy range : 1000 – 5000 keV
Steps: Varying (excitation function depending)
Target: 11B, 10B on thick Ta
Angle: 55o
10B(p,αγ) 7Be
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
Experiment
Energy range : 1000 – 5000 keV
Steps: Varying depending on the excitation function
Target: Gold on 13C foil
Angle: 55o - 90o - 125o
Candidates:
Proposed Measurement for Proposed Measurement for 1313CC
13C(p, γ) 14N on 1.75 MeV resonance 90% Εγ = 9.16 MeV J. B. Marion et al. Phys. Rev. 104 (1956), 1028
H. H. Woodbury et al. Phys. Rev. 92 (1953), 1199
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
ConclusionsConclusions
Means for target characterization
Effective charge measurement
Efficient HPGe experimental setup
A set of case studies
Appropriate software for validation
PIGE cross sections
Summary
A. LagoyannisInstitute of Nuclear PhysicsNCSR “Demokritos”
CollaboratorsCollaborators
A. Axiotis, V. Paneta and S. Harissopulos
M. Kokkoris
P. Misaelides
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