PIGE and resonant PIGE: Past efforts and current needs

M. Kokkoris,National Technical University of Athens, Greece

Structure of the Presentation:

1. Historical Aspects2. Status in Literature3. Present Status4. Interesting Contributions (since 1990)5. Relevant Works from our Team6. Experimental Capabilities – Tandem Accelerator7. Future Measurements and Perspectives

1. Historical Aspects

First (?) well-known publication introducing NRA in 1962 (the original acronym refers to: Nuclear Reaction microAnalysis): ‘The Mechanism of Anodic Oxidation’, G. Amsel, D. Samuel, Journal of Physics and Chemistry of Solids [involves 18O(p,α) and 27Al(p,γ)]

First ‘Fight’: 1968 between B. Cox and G. Amsel over the use of the 16O(d,p) reaction for the study of oxygen diffusion in solids [raises questions about the shape of the cross section needed for profiling]

First Ion Beam Analysis Conference: 1975

First Review Article on the Field: 1984 (‘Nuclear Reaction Techniques in Materials Analysis’, G. Amsel, W.A. Lanford, Annual Review of Nuclear and Particle Science 34: 435-460

2. Status in LiteratureIt can be divided into 3 time periods: ‘Early years’ (>1960-1980), ‘Development’ (1980-1990), ‘Data and Applications’ (1990-today)There is a great problem in terminology: The terms NRA, resonant NRA, PIGE, AIGE, DIGE, HIGE or nothing (!) have been used to describe the same technique, namely ‘material analysis implementing nuclear data from low-energy γ-ray emission reactions’. I could not find when the modern term (Particle Induced Gamma-ray Emission) was first introduced – still the community is divided. Here follows a short list (# papers, many have been omitted):

TERM >1960 – 1990 1990 – today Main Journal

PIGE ~45 ~285 Nucl. Instr. and Meth. (191), J. Rad. And Nucl. Chem. (24)

NRA ~100 (mixed) ~770 (mixed) Nucl. Instr. and Meth. (340), J. Nucl. Materials (~60)

DIGE ~20 Nucl. Instr. and Meth. (9), Proc. AMS (7)

AIGE ~5 -

HIGE ~2-3 -

2. Status in Literature

Remarks: The term ‘NRA’ remains almost time – invariant in paper production, the term ‘PIGE’ is related to the IBA conference proceedings (increase by a factor of ~2), denoting ‘applications’ not methodology or new data (especially after 2000)!

‘PIGE’ ‘NRA’ (more than 50% involve γ-rays)

No more than 20-30 papers concern nuclear data, methodology, software and analysis data over the last ~20 years! What is the meaning of this?

3. Present Status

According to an IAEA survey there are ~200 small VdG type accelerators over 40 countries. One can assume that PIGE capabilities are available practically everywhere.

PIGE is usually combined with PIXE (competition): PIXE is generally preferred for Z>20 elements due to the much higher cross sections involved, and the existence of reliable, widely used analysis software (GUPIX etc.)

R-PIGE is usually combined with / compared to RBS/EBS/ERDA/NRA (with charged particles): The former has superior depth resolution but it is time-consuming, and cannot depth profile efficiently all light isotopes/elements, while the latter are based on reliable, widely used analysis software (SIMNRA, WINDF etc.), evaluated and new data + library (IBANDL). How are PIGE measurements performed in the vast majority of cases? NOT absolutely, but through comparisons with standards.

Present situation in software: IAEA has organized CRPs for software evaluation for all the other profiling techniques, but not for r-PIGE! Namely, ‘IAEA intercomparison of IBA software’ N.P. Barradas et al., Nucl. Instr. and Meth. B262 (2007) 281, ‘Intercomparison of PIXE Spectrometry Software Packages’, IAEA-TEXDOC-1342. There have been two CRPs for γ-rays’ software, but they did not touch the ‘core’ of PIGE, that is, how to perform material analysis + element profiling: ‘Intercomparison of γ-Ray Analysis Software Packages’, IAEA-TEXDOC-1011, and ‘Specialized Software Utilities for γ-Ray Spectrometry’, IAEA-TEXDOC-1275. As a result, all labs use home made codes (Greece: PGAMMA, Portugal: ERYA, etc.) , thus how reliable are the obtained results?

Present situation in data: PIGE involves (p,γ), (α,γ), (p,αγ), (p,p’), (d,nγ), (d,pγ) etc. reactions in light and medium-Z elements with and without strong resonances. Data exist in EXFOR (mainly) in the form of ‘absolute reaction yield’, ‘total cross section’, ‘differential cross section’. What is really needed? What is lacking?

3. Present Status

Present situation in scientific politics: Most traditional Nuclear Physics labs in low energy reaction physics have shifted their efforts to Nuclear Astrophysics, involving γ-ray measurements for medium, medium-heavy ions. Possible reasons: a) ‘Modern’, exciting field, good for young researchers, more closely related to NP than to CM Physics, b) Theoretical treatment is easier (HF calculations, several software codes available etc.) c) Publications in several high impact factor journals (PRC, NP, EPJ) d) Existence of several academic position openings while IBA is more closely related to accelerator labs.

Present situation in IBA: All competitive techniques, as shown before, are in a better starting point. PIGE tends to become a ‘supplementary’ technique and to assume a semi-quantitative nature (indirect comparison with standards).

3. Present Status

Portugal: Contributions both in cross section measurements for the most important light elements with thin targets (23Na, 7Li, 19F, 10B, 27Al) and in methodology (software, sensitivity etc.).

Italy: Contributions mainly in cross section measurements (19F, 7Li, 23Na) using thin targets.

Hungary and Greece: Contributions in d-PIGE and PIGE for several light and medium-Z elements using thick targets and usually calculating absolute thick target yields.

Russia and Finland: Thick target γ-ray yields and methodology.

Spain and Germany: Thick target γ-ray measurements for 14N.

Romania: Interesting applications in coincidence with neutrons.

4. Interesting Contributions (since 1990)

1. ‘On the Determination of Beryllium in Light Element Matrices using PIGE and NRA’, G. Perdikakis, A. Spyrou, M. Kokkoris et al., Nucl. Instr. and Meth. B 226 (2004) 622-630.

2. ‘Fluorine Determination in Human Healthy and Carious Teeth using the PIGE Technique’, M.L. Carvalho, C. Casaca, A.G. Karydas, M. Kokkoris et al., Nucl. Instr. and Meth. B 179 (2001) 561-567.

3. ‘Analysis of Ancient Glass using Ion Beams and Related Techniques’, S. Kossionides, M. Kokkoris et al., Nucl. Instr. and Meth. B 195 (2002) 408-413.

4. ‘Investigation of Deep Implanted Fluorine Channeling Profiles in Silicon using Resonant NRA’, M. Kokkoris, R. Groetzschel et al., Nucl. Instr. and Meth. B 201 (2003) 623-629.

5. ‘Determination of Sulphur and Copper Depth Distribution in Patina Layers Using NRA’, P. Misaelides et al., Nucl. Instr. and Meth. B 170 (2000) 467-473.

6. ‘Proton Induced Thick Target γ-Ray Yields of Light Nuclei at the Energy Region Ep=1.0-4.1 MeV’, T. Paradellis et al., Nucl. Instr. and Meth. B 152 (1999) 12-18.

7. ‘Analysis of Copper Alloys by Proton Beams’, A.A. Katsanos, B. Katselis, A. Aravantinos, Nucl. Instr. and Meth. B 15 (1986) 647-650.

5. Relevant Works from our Team

PIGE Data and Applications (1/2):

8. ‘Cross-sections of the 32S(p,p’γ)32S nuclear reaction used for the determination of sulfur on materials surfaces’, Ch. Tsartsarakos, P. Misaelides, A. Katsanos, Nucl. Instr. Meth. B45 (1990) 33.

9. ‘Application of the 27Al(p,γ)28Si nuclear reaction to the characterization of the near-surface layers of acid-treated HEU-type zeolite crystals’, P. Misaelides, A. Godelitsas, F. Link, H. Baumann, Microporous Materials 6 (1996) 37.

10. ‘Aluminium diffusion in Al-implanted AISI 321 stainless steel using accelerator-based characterization techniques’ Noli, P. Misaelides, K. Bethge: Nucl. Instr. and Meth. B139 (1998) 322.

11. ‘Investigation of fluorine distribution on the surface of acid-treated apatite single crystals using nuclear resonant reaction analysis’, W. Theodossiu, P. Misaelides and A. Godelitsas, Cryst. Res. Technol. 36 (2001) 1147-1151.

12. Determination of copper and sulphur distribution on chemically modified HEU-type zeolite crystals by means of nuclear resonant reaction analysis techniques, scanning electron microscopy and X-ray fluorescence’ A. Godelitsas, P. Misaelides, D. Charistos and E. Pavlidou, Application of Particle and Laser Beams in Materials Technology, P. Misaelides (Ed.), Kluwer Academic Publishers, Dordrecht, 1995, pp. 493-500.

13. ‘Investigation of natural prehnite using spectroscopic and accelerator-based analytical techniques’ Α. Godelitsas, P. Misaelides, N.K. Moroz, R.S.W. Braithwaite, S.P. Gabuda, A. Filippidis, K. Bethge, 6th V.M. Goldschmidt Conference, Heidelberg, 1996, Journal of Conference Abstracts 1 (1), 205 (1996).

5. Relevant Works from our Team

PIGE Data and Applications (2/2):

1. Cross section measurements of (p,γ) reactions on Pd isotopes relevant to the p process Spyrou, A., Lagoyannis, A., Demetriou, P., Harissopulos, S., Becker, H.-W. 2008 Physical Review C - Nuclear Physics 77 (6), art. no. 065801

2. Cross-section measurements of capture reactions relevant to the p process using a 4π γ-summing method Spyrou, A., Becker, H.-W., Lagoyannis, A., Harissopulos, S., Rolfs, C. 2007 Physical Review C - Nuclear Physics 76 (1), art. no. 015802

3. Alpha-capture reactions relevant to the p-process nucleosynthesis Spyrou, A., Lagoyannis, A., Zarkadas, Ch., Demetriou, P., Harissopulos, S., Becker, H.-W., Strieder, F., (...), Julin, R. 2006 AIP Conference Proceedings 831, pp. 314-318

4. Proton and alpha-particle capture reactions at sub-Coulomb energies relevant to the p process Harissopulos, S., Lagoyannis, A., Spyrou, A., Zarkadas, Ch., Galanopoulos, S., Perdikakis, G., Becker, H.-W., (...), Demetriou, P. 2005 Journal of Physics G: Nuclear and Particle Physics 31 (10), pp. S1417-S1420

5. Systematic measurements of proton- and alpha-capture cross sections relevant to the modelling of the p process, Harissopulos, S., Spyrou, A., Lagoyannis, A., Zarkadas, Ch., Becker, H.-W., Rolfs, C., Strieder, F., (...), Goriely, S. 2005 Nuclear Physics A 758 (1-4 SPEC. ISS.), pp. 505c-508c

6. Cross section measurements of the 89Y(p, γ)90Zr reaction at energies relevant to p-process nucleosynthesis Tsagari, P., Kokkoris, M., Skreti, E., Karydas, A.G., Harissopulos, S., Paradellis, T., Demetriou, P. 2004 Physical Review C - Nuclear Physics 70 (1), pp. 015802-1-015802-10

5. Relevant Works from our Team

Other γ-Ray Measurements for Nuclear Astrophysics (1/2):

7. Proton induced reaction cross section measurements on Se isotopes for the astrophysical p process Gyurky, Gy., Fulop, Zs., Somorjai, E., Kokkoris, M., Galanopoulos, S., Demetriou, P., Harissopulos, S., (...), Goriely, S. 2003 Physical Review C - Nuclear Physics 68 (5), pp. 558031-5580319

8. Se(p-γ) cross section measurements for p-process studies Gyürky, G., Fülöp, Zs., Somorjai, E., Elekes, Z., Kokkoris, M., Galanopulos, S., Demetriou, P., (...), Rauscher, T. 2003 Nuclear Physics A 723 (1-2), pp.599c-601c

9. A systematic study of proton capture reactions in the Se-Sb region at energies relevant to the p process Harissopulos, S., Galanopoulos, S., Demetriou, P., Spyrou, A., Kriembardis, G., Kokkoris, M., Karydas, A.G., (...), Goriely, S. 2003 Nuclear Physics A 719 (1-4), pp. 115c-118c

10. The 88Sr(p,γ)89Y reaction at astrophysically relevant energies Galanopoulos, S., Demetriou, P., Kokkoris, M., Harissopulos, S., Kunz, R., Fey, M., Hammer, J.W., (...), Goriely, S. 2003 Physical Review C - Nuclear Physics 67 (1), pp. 158011-1580110

11. Proton capture cross section of Sr isotopes and their importance for nucleosynthesis of proton-rich nuclides Gyürky, Gy., Somorjai, E., Fülöp, Zs., Harissopulos, S., Demetriou, P., Rauscher, T. 2001 Physical Review C -Nuclear Physics 64 (6), pp. 658031-658038

12. Cross section measurements of the 93Nb(p,γ)94Mo reaction at Ep=1.4-4.9 MeV relevant to the nucleosynthetic p process Harissopulos, S., Skreti, E., Tsagari, P., Souliotis, G., Demetriou, P., Paradellis, T., Hammer, J.W., (...), Rauscher, T. 2001 Physical Review C - Nuclear Physics 64 (5), pp. 558041-558049

5. Relevant Works from our Team

Other γ-Ray Measurements for Nuclear Astrophysics (2/2):

1. The 27Al(p, γ)28Si reaction: Direct capture cross-section and resonance strengths at Ep = 0.2-1.12 MeV, Harissopulos, S., Chronidou, C., Spyrou, K., Paradellis, T., Rolfs, C., Schulte, W.H., Becker, H.W. 2000 European Physical Journal A 9 (4), pp. 479-489.

2. Cross section and resonance strength measurements of 19F(p,αγ)16O at Ep = 200-800 keV Spyrou, K., Chronidou, C., Harissopulos, S., Kossionides, S., Paradellis, T., Rolfs, C., Schulte, W.H., Borucki, L. 2000 European Physical Journal A 7 (1), pp. 79-85.

3. Resonance strength measurements of the 27Al(p,γ)28Si reaction in the energy range Ep = 0.8 - 2.0 MeV Chronidou, C., Spyrou, K., Harissopulos, S., Kossionides, S., Paradellis, T. 1999 European Physical Journal A 6 (3), pp. 303-308.

4. A compilation of charged-particle induced thermonuclear reaction rates Angulo, C., Arnould, M., Rayet, M., Descouvemont, P., Baye, D., Leclercq-Willain, C., Coc, A., (...), Lamehi Rachti, M. 1999 Nuclear Physics A 656 (1), pp. 3-183.

5. Relevant Works from our Team

Other γ-Ray Measurements for Nuclear Astrophysics (but PIGE related):

(2006 – today)

4 HPGe Detectors, ~100% relative efficiency for 6 months/year in the framework of the LIBRA project (from Stuttgart’s Dynamitron): 3 could be set at 55o, 125o and 90o for PIGE measurements, but there also exist 4 portable HPGe detectors (rel. eff. 80%, 50%, 45%, 18%)

6. Experimental Capabilities – Tandem Accelerator

7. Future Measurements and Perspectives

Data and Software:

1. The situation seems to be quite complicated. In my opinion, no new data library is needed, EXFOR or IBANDL (even better) are adequate. A new CRP is absolutely necessary to stimulate and organize the field and it should be mainly concentrated on data needs / new measurements.

2. The CRP should accept realities and concentrate on r-PIGE or PIGE in general, but setting an upper limit in Z (e.g. 20-25 at the most).

3. The new measurements should follow certain guidelines in order to be useful for the scientific community (cross sections, differential or total, thin targets, analogous situation as in the recent CRP for IBA)

4. The final outcome of the CRP should be a complete ‘guide’ for PIGE users, for the profiling of all the light elements and a big review article should be produced, in parallel of the other IAEA requirements.

5. In this aspect, we would like to contribute e.g. in the cases of 9Be(p,γ), 13C(p,γ) and 32S(p,p’) [resonant – non-resonant parts] or according to the recommendations of the other members of the present meeting.

6. All new datasets will be of limited use, unless the software situation concerning light element profiling utilizing PIGE cross sections is also addressed in this forthcoming CRP. A recommended code should be made available to the scientific community and supported by benchmarking experiments (round-robin?).

7. The theoretical /evaluation part should also be addressed.