## Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

#### Article Title

### Investigation of isomer ratios in the reactions (γ, *n*) and (*n*, 2*n*) on nuclei ^{76}Ge and ^{82}Se

#### Abstract

The method of the induced activity measured the isomeric yield ratios and cross-sections ratios of reactions (γ, *n*) and (*n*, 2*n*) on nuclei ^{76}Ge and ^{82}Se. 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 ^{60}Co, 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 = Y_{m}/(Y_{m} + Y_{g}) at E_{γ max} = 30 MeV for the reaction (γ, n) on nuclei ^{76}Ge and ^{82}Se are respectively: 0.55±0.02 and 0.36±0.01 (Y_{m}/Y_{g} = 0.56±0.02). In the range 26-35 MeV the isomeric yield ratios η of the reaction (γ, n) on _{76}Ge and _{82}Se are obtained at first. The isomeric cross-section ratios σ_{m}/σ_{g} 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 ^{27}Al(n, α) ^{24}Na (T_{1/2} = 15 h, E_{γ} = 1368 keV), whose cross section γm was 121.57±0.57 mb at E_{n}= 14.1 MeV, was taken for a monitoring reaction.

#### First Page

246

#### Last Page

256

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#### Recommended Citation

Palvanov, Satimbay and Akhmadzhanov, Turgunali
(2019)
"Investigation of isomer ratios in the reactions (γ, *n*) and (*n*, 2*n*) on nuclei ^{76}Ge and ^{82}Se,"
*Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences*: Vol. 2:
Iss.
4, Article 3.

DOI: https://doi.org/10.56017/2181-1318.1043