Generation and Application of Bremsstrahlung Production Data Calculated by EGS4 Code

Bremsstrahlung radiation (hereinafter referred to as bremsstrahlung) production data are needed in the calculation of buildup factors, including the contribution of secondary photons by the photon transport codes, which do not handle electron transport. The emission of bremsstrahlung is treated as exactly as possible by the introduction of EGS4 results. The bremsstrahlung production data by pair-created electrons per pair creation reaction and Compton scattered electrons per Compton scattering are evaluated for 26 elements from hydrogen to uranium and four compounds and mixtures of water, concrete, air, and lead glass. The error estimation of bremsstrahlung contribution to buildup factors by the invariant embedding (IE) method coupled with these bremsstrahlung data is coincident with fully transported results by the EGS4 code within [approximately]5%. By the introduction of bremsstrahlung production data into IE methods, we can calculate buildup factors included by the contribution of those with good accuracy up to deep penetration. By the interpolation and mixture of bremsstrahlung production data for each element, we can evaluate the data of the element or mixture whose data are not evaluated by the EGS4 code.