New algorithm for Monte Carlo particle-transport simulation to recover event-by-event kinematic correlations of reactions emitting charged particles

Ogawa, Tatsuhiko   ; Sato, Tatsuhiko   ; Hashimoto, Shintaro  ; Niita, Koji*

We develop a new radiation transport calculation algorithm to recover event-by-event quantities based on inclusive cross-section data with conserving energy and momentum. In radiation transport calculations based on inclusive cross-section data, conventional algorithms could predict average behavior of the particles, however, they could not consider fluctuations around the average. Moreover, calculation of kinematics among secondary particles and recoiled residues resulted from reactions were out of their scope. To overcome these difficulties, we developed a new algorithm which reproduces particle emission in each reaction in exact accordance with the chosen reaction channel. The algorithm makes it possible to predict event-by-event quantities such as nuclear recoil, secondary particle and energy spectra, in all kinds of reaction channels. To evaluate the impact of the new algorithm, it was applied to various simulation studies such as dose conversion coefficient evaluation, soft-error analysis and radiation damage prediction. The calculated data shows that the new algorithm is indispensable for such simulation studies.