MONTE CARLO CALCULATION OF THERMAL AND EPITHERMAL NEUTRON SELF-SHIELDING FACTORS

VUONG HUU TAN1, PHAM NGOC SON2, PHU CHI HOA3, BACH NHU NGUYEN4
1 Viennam Atomic Energy Institute, 59 Ly Thuong Kiet, Hanoi
2 Nuclear Research Institute, 01 Nguyen Tu Luc, Dalat
3 The University of Dalat, 01 Phu Dong Thien Vuong, Dalat
4 Presentative Office of Ministry of Information and Communications, 42-Tran Quoc Toan, Danang

Main Article Content

Abstract

Neutron activation measurement is often performed in a reactor based neutron spectrum. When the size of the irradiation sample is not small enough and resonance peaks present in the cross section of the sample nuclide, the thermal and
resonance self-shielding effects of neutron flux distribution in the sample must be considered for correction. In this work, the Monte Carlo code MCNP-5 has been applied for calculation of the self-shielding factors for several standard samples
and neutron monitors that are often used in measurements of thermal neutron capture cross sections and resonance integrals. The results of calculation are tabulated with different sample thickness and different irradiation geometries.

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References

[1] E. Martinho, J. Salgado, I. F. Goncalves, Universal cure of thermal neutron resonance self-sheilding factors in foils, wires and spheres. Journal of Radioanalytical and Nuclear Chemistry, Vol 261, No. 3 637-643 (2004).
[2] M. Brose, Zur messung und berechnung der resonanzabsorp-tion von neutronen in goldfolien, Nukleonik, 6, 134 (1964).
[3] Oleg Shcherbakov, Hideo Harada, Resonance Shelf-Shielding Corrections for Activation Cross Section Measurements, Journal of Nuclear Science And Technology, Vol. 39, No. 5, p. 548-553.