ANALYSIS OF AMBIGUITIES IN THE DETERMINATION OF CROSS SECTIONS OF THE RADIOISOTOPES 99mTc, 177Lu FORMATION

Abstract

Experimental data on cross-section values of the formation of medical radioisotopes 99mTc, 177Lu in photonuclear reactions  are compared with evaluated data and calculations made taking into account uncertainties in the characteristics of excited states of atomic nuclei. The experimental data from the EXFOR database are given with sufficiently large uncertainties, and modern evaluated data from the TENDL2023 data library at many energies do not agree with the experimental data. Therefore, in order to reliably determine the corresponding photoabsorption cross-sections that determine the production of radioisotopes, in this work calculations of the corresponding cross-sections were performed taking into account the uncertainties in the characteristics of excited states of nuclei, namely in the form of photon strength function that determines the probability of gamma decay and photoabsorption of nuclei, and in expressions for the densities of excited states of atomic nuclei. A rather strong dependence of the values of the radioisotope formation cross sections on the characteristics of the states has been demonstrated, but no variation of the parameters can agree the theoretical calculations with the experimental cross section data for the formation of 177Lu radioisotope. Calculations of photoabsorption cross sections of 100Mo, 178Hf nuclei with different deformations utilizing systematics for giant dipole resonances are shown.

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