Intercomparison of low-energy electron transport calculations by different Monte Carlo track-structure simulation codes

Kyriakou, I.*; Papadopoulos, A.*; Polopetrakis, I.*; Kotroumbelou, C.*; Plante, I.*; Matsuya, Yusuke  ; Kai, Takeshi   ; Qiu, R.*; Li, J.*; Kundrt, P.*; Baiocco, G.*; Huang, C.-W.*; Lillhk, J.*; Billnert-Marti, R.*; Di Maria, S.*; Tran, H.*; Perrot, Y.*; Villagrasa, C.*; Dingfelder, M.*; Rabus, H.*; Li, W.*; Incert, S.*; Emfietzoglou, D.*

Several Monte Carlo Track-Structure (MCTS) codes for liquid water have been developed worldwide over the last 40 years; however, use the different interaction cross sections. This study evaluates the uncertainties of physical features (electronic stopping power, pathlength, dose-point-kernel, and microdosimetry) of low-energy electron transport in liquid water by using 6 types of MCTS codes. The intercomparison results reveal significant differences among MCTS codes at low energies, especially below ~100 eV, potentially compromising the accuracy of DNA damage simulations where such electrons play a key role. The present work highlights the need for further development of the physics models used in MCTS codes to reduce the uncertainties associated with low-energy electron transport calculations in liquid water.