An Improved Approximation Formula of Gamma-Ray Buildup Factors for a Point Isotropic Source in Two-Layer Shields

Autor:	Yukio Sakamoto, Hideo Hirayama, Yoshiko Harima, Naohiro Kurosawa
Rok vydání:	2000
Předmět:	Nuclear and High Energy Physics business.industry Chemistry Isotropy Reference data (financial markets) Gamma ray Bremsstrahlung Shields Computational physics Optics Nuclear Energy and Engineering Point (geometry) business Energy (signal processing) Interpolation
Zdroj:	Journal of Nuclear Science and Technology. 37:488-492
ISSN:	1881-1248 0022-3131
Popis:	An approximation formula of buildup factor for two-layer shields proposed previously was improved to fitting to the newly calculated buildup factors for point isotropic source gamma-rays of 0.1, 0.3, 0.6, 1,3,6 and 10 MeV penetrating two-layer shields combinations of water, iron or lead materials with the Monte Carlo code EGS4 included the effects of Bremsstrahlung and fluorescent radiations. A f-function in the formula was modified to reproduce precisely the reference data up to the total thickness 40 mfp and the value of buildup factor at the interface of two-layer shields. The functions α and β used in improved f-function f(x1,x2) = α(x1)/{α(x1)+B2(x1)*β(x1,x2)x2} were represented by simple formula fitted to reference data in excellent agreement. Consequently, the two-layer shields buildup factor for any arbitrary thickness of the first-layer x1, and the second-layer x2, and for arbitrary source energy can easily be estimated by interpolation of functions α and β with respect to energy.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::03489ec52f2d080ec5e45231baa908e3 https://doi.org/10.1080/00223131.2000.10874934 Zobrazit plný text záznamu