Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences


The method of the induced activity measured the isomeric yield ratios and cross-sections ratios of reactions (γ, n) and (n, 2n) on nuclei 76Ge and 82Se. Samples of natural have been irradiated in the bremsstrahlung beam of the betatron SB-50 of National University of Uzbekistan in the energy range of 10-35 MeV with energy step of 1 MeV. For 14 MeV neutron irradiation, we used the NG-150 neutron generator of Institute of Nuclear Physics. The gamma spectra reactions products were measured with a spectroscopic system consisting of HPGe detector CANBERRA with energy resolution of 1.8 keV at 1332 keV gamma ray of 60Co, amplifier 2022 and multichannel analyzer 8192 connected to computer for data processing. The filling of the isomeric and ground levels was identified according to their γ lines. Values η = Ym/(Ym + Yg) at Eγ max = 30 MeV for the reaction (γ, n) on nuclei 76Ge and 82Se are respectively: 0.55±0.02 and 0.36±0.01 (Ym/Yg = 0.56±0.02). In the range 26-35 MeV the isomeric yield ratios η of the reaction (γ, n) on 76Ge and 82Se are obtained at first. The isomeric cross-section ratios σmg was determined in the case of the reaction (n, 2n). In order to obtain the absolute values of the cross sections for the ground state and for the isomeric state, use was made of methods based comparing the yields of the reaction under study and the monitoring reaction. The reaction 27Al(n, α) 24Na (T1/2 = 15 h, Eγ = 1368 keV), whose cross section γm was 121.57±0.57 mb at En= 14.1 MeV, was taken for a monitoring reaction.

First Page


Last Page



1. Gangrsky Yu.P., Tonchev A.P., Balabanov N.P. Excitation of isomeric states in photonuclear reactions. Phys. Part. Nucl., Vol. 27, Issue 34, 428–471 (1996).

2. Mazur V.M. Nuclear isomeric states excitation in the (γ,n) reaction within the dipole giant resonance region. Phys. Part. Nucl., Vol. 31, No. 1, 188–210 (2000).

3. Davydov M.G., Magera V.G., Trukhov A.V. Isomeric ratios of the yields (cross sections) of photonuclear reactions. Sov. At. Energy, Vol. 62, No. 4, 236–277 (1987).

4. Palvanov S.R. Excitation of isomeric states in the reactions (γ,n), (n,2n), and (γ,2n) on the 113In. Physics of Atomic Nuclei, Vol. 77, No. 1, 35–38 (2014).

5. Gangrskiy Yu.P., Zuzaan P., Kolesnikov N.N., Lukashik V.G., Tonchev A.P. Izomeric ratios in cross reactions (n,γ) and (γ,n). Bull. Russ. Acad. Sci. Physics, Vol. 65, No. 1, 111–116 (2001).

6. Palvanov S.R., Razhabov O. Isomeric yield ratios in photonuclear reactions at Eγ max 25 and 30 MeV. Atomic Energy, Vol. 87, Issue 1, 533–536 (1999).

7. Babadzhanov R.D., Palvanov S.R., Razhabov O., Shelemet'ev G.L. Equipment for intrachamber irradiation of samples by betatron Bremsstrahlung. Pribory i Tekhnika Ehksperimenta, No. 2, 10–11 (1997).

8. Lederer C.M., Shirley V.S. Table of isotopes. 7th ed. John Wiley, New York, (1978).

9. Firestone R.B. Table of isotopes. Wiley-Interscience, (1996).

10. Vanska R., Rieppo R. The experimental isomeric cross-sections ratio in the nuclear activation technique. Nucl. Instrum. Meth., Vol. 179, Issue 3, 525–532 (1981).

11. Antonov A.D. et al. Report of 41-th conference on nuclear spectroscopy and structure of atomic nucleus. Publishing House Science, Sankt-Peterburg, 286 (1991). [in Russian]

12. Mazur V.M., Sokolyuk I.V., Bigan Z.M. Transversal cross sections of (γ,n)m reaction for 78,80,82Se in region of giant E1-resonance. Yadernaya Fizika, Vol. 54, No. 4, 895–900 (1991).

13. Davydov M.G., Magera V.G., Trukhov A.V., Shomurodov É.M. Isomeric ratios of the yields of photonuclear reactions for gamma-activation analysis. Soviet Atomic Energy, Vol. 58, No. 1, 56–59 (1985).

14. Thiep T.D., An T.T., Khai N.T., Cuong P.V., Vinh N., Belov A.G., Maslov O.D. Study of the isomeric ratios in photonuclear reactions of natural Selenium induced by bremsstrahlungs with end-point energies in the giant dipole resonance region. Journal of Radioanalytical and Nuclear Chemistry, Vol. 292, Issue 3, 1035–1042 (2012).

15. Varlamov A.V., Varlamov V.V., Rudenko D.S., Stepanov M.E. Atlas of Giant Dipole Resonances. Vienna, INDS (NDS)-394, IAEA, (1999).

16. Agostinelli S., Allison J., Amako K. et al. Geant4–a simulation toolkit. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, Issue 3, 250–303 (2003).

17. Bogdankevich O.V., Nicolaev F.A. Methods in Bremsstrahlung Research. Academic Press, (1966).

18. Koning A.J., Hilarie S., Duijvestijn M.C. TALYS-1.0. Proceedings of the International Conference on Nuclear Data for Science and Technology, 22–27 April 2007, Nice, France, 211–214 (2007).

19. Carlos P., Beil H., Bergère R., Fagot J., Leprêtre A., Veyssière A., Solodukhov G.V. A study of the photoneutron contribution to the giant dipole resonance of nuclei in the 64≤A≤86 mass region. Nuclear Physics A, Vol. 258, Issue 2, 365–387 (1976).

20. Greenwood L.R. Recent research in neutron dosimetry and damage analysis for materials irradiations. Influence of Radiation on Material Properties: 13th International Symposium (Part II), ed. F. Garner, C. Henager, and N. Igata (West Conshohocken, PA: ASTM International), 743–749 (1987).

21. He G., Liu Z., Luo J., Kong X. Cross-section measurements of (n,2n), (n,p) and (n,α) reactions on some selenium isotopes near En=14 MeV. Indian Journal of Pure and Applied Physics, Vol. 43, 729–732 (2005).

22. Luo J., Xu X., Cao X., Kong X. Activation cross sections and isomeric cross section ratios for the (n,2n) reactions on 175Lu, 198Pt and 82Se from 13.5 to 14.6 MeV. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 265, Issue 2, 453–460 (2007).

23. Grochulski W., El-Konsol S., Marcinkowski A. Excitation curves for fast neutron induced reactions on 71Ga, 75As, 80Se, 82Se, 117Sn and 118Sn nuclei. Acta Physica Polonica, Part B, Vol. 6, No. 1–2, 139–145 (1975).

24. Hasan S.S., Prasad R., Seghal M.L. The 14.8 MeV neutron cross sections for enriched isotopes of 82Se, 92Mo, 117Sn, 128Te and 130Te. Nuclear Physics A, Vol. 181, Issue 1, 101–105 (1972).

25. Attar F.M.D., Dhole S.D., Kailas S. et al. Cross-section for the formation of isomeric pair 75Gem,g through (n,2n), (n,p) and (n,α) reactions measured over 13.73 MeV to 14.77 MeV and calculated from near threshold to 20 MeV neutron energies. Nuclear Physics A, Vol. 828, Issues 3–4, 253–259 (2009).

26. Birn I., Qaim S.M. Excitation Functions of Neutron Threshold Reactions on Some Isotopes of Germanium, Arsenic, and Selenium in the 6.3- to 14.7-MeV Energy Range. Nuclear Science and Engineering, Vol. 116, Issue 2, 125–137 (1994).

27. Casanova J.L., Sanchez M.L. Measurement of the (n,p), (n,α), (n,2n) Cross Sections of Zn, Ga, Ge, As, and Se for 14.1 MeV Neutrons, and (n,p) Cross Sections Analysis. Anales de Fisica y Quimica, Vol. 72, 186–189 (1976). [in Spanish]

28. Bhike M., Krishichayan, Tornow W. Total and isomeric-state cross sections for the 76Ge(n,2n) 75Ge reaction from threshold to 14.8 MeV. Physical Review C, Vol. 95, Issue 5, 054605 (2017).

Included in

Nuclear Commons



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.