1. Benchmarking cross sections for PIGE The Fluorine case
M. Axiotis1, A. Lagoyannis1, K.Preketes-Sigalas1,2, S. Fazinic3,
V. Foteinou1, S. Harissopulos1, M. Kokkoris2 G.Provatas1
1Institute of Nuclear and Particle Physics, NCSR “Demokritos”,
2 Department of Physics, National Technical University of Athens
3 Institute Ruđer Bošković, Zagreb, Croatia

2. PIGE Proton Induced Gamma – ray Emission Quantification
Traditional way: Comparison of yields with standards
IAEA has initiated a program for
measuring differential cross sections
aiming at a standard-less method

3. Differential Cross Sections
23Na(p,p’γ1-0)23Na
Eγ = 440 keV
19F(p,p’γ2-0)19F
Eγ = 197 keV
Possible reasons
Target thickness
Charge accumulation
Efficiency calibration
Background subtraction

4. The Concept Differential cross section Thick target yield
Target thickness
No need. Standards of known concentration are sufficient
Charge accumulation
Cross check with a well studied element in the same standard
Efficiency calibration
Background subtraction
Huge peak to background ratio

5. Test Case: Sodium
The majority of cross sections reproduce the measured thick target yields

6. Existing thick target yields
The Fluorine Case
BUT
At Ep = 2200 keV
Integrated yield: 3.1 x 106
Measured yield: 8.7 x 105
Except from
M.J. Kenny et al.

7. Experimental Setup Two detectors in two different angles
Ep = 1700 – 4000 keV
Efficiency calibration with two different sources (152Eu, 226Ra)
Two different standards containing Fluorine and Sodium
Chamber acting as Faraday cup
Difference in background subtraction ~ 1%

8. (for details see K. Preketes – Sigalas talk)
Comparison of Integrated Yields
Sodium
(for details see K. Preketes – Sigalas talk)
NIST standard
Phospate Rock
Na = 0.26 at%
F = at%
Home Made
standard
Na = 5.3 at%
F = 5.3 at%

9. Comparison of Integrated Yields
Fluorine

10. Comparison of Integrated Yields
????????