Application of the smart scattering method to generate an extended first collision source for electron and proton beam source problems

Abstract

Charged particle beam source problems are difficult to simulate because of the extremely large and anisotropic scattering cross sections, and the associated singularities in angle and space. To overcome these difficulties the Extended First Collision Source method and the SMART (Simulation of Many Accumulative Rutherford Trajectories) scattering method have been developed. In this study, the extended first collision source calculation was improved in the SN code using the SMART scattering method which produces smoother and smaller effective cross sections. To determine the uncollided flux which was necessary for the first collision source calculation, the SMART scattering cross sections were used instead of screened Rutherford scattering cross sections. After the SN code was modified, it produced results that approached those obtained using the benchmark Monte Carlo code.