A new hybrid next-event estimator for photon-based Monte Carlo dose rate calculations

This work describes the implementation of a deterministic-like straight-line transport routine inside the TRIPOLI-4®\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {TRIPOLI-4}^{\circledR }$$\end{document} Monte Carlo code, aimed at developing a hybrid estimator that can speed up the MC calculation while retaining its precision. The algorithm is based on the exponential track length estimator or eTLE, a next-event estimator that has already been investigated for medical applications. In this implementation, the eTLE is paired with a forced detection algorithm. We describe the implementation of the method in TRIPOLI-4®\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {TRIPOLI-4}^{\circledR }$$\end{document}, then we present the first results obtained over some test cases and compare them with the classic track-length estimator already implemented in TRIPOLI-4®\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {TRIPOLI-4}^{\circledR }$$\end{document}. These results show that the forced detection technique drastically improves the eTLE performance.