Monte Carlo simulation of fast electron and proton tracks in liquid water - I. Physical and physicochemical aspects
Monte Carlo simulation of fast electron and proton tracks in liquid water - I. Physical and physicochemical aspects
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DOI：
10.1016/s0969-806x(97)00096-0
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发表时间：
1998-03-01
影响因子：
2.9
通讯作者：
Jay-Gerin, JP
中科院分区：
文献类型：
--
作者：
Cobut, V;Frongillo, Y;Jay-Gerin, JP
蒙特卡罗模拟技术已用于对电离辐射与纯液态水相互作用产生的事件序列进行建模。这些事件包括（i）通过水分子的电离和激发而发生的能量沉积； (ii) 亚激发电子、瞬态水阴离子和阳离子以及激发态水分子的弛豫路径和超快反应。当辐射分解物质扩散到介质中时，随后沿辐射轨迹发生的均质和非均质化学反应将在以下论文中讨论（Frongillo ct at.，1998a）。我们的模拟代码所依据的原理和物理定律得到了一些详细的解释，以确定它们的优点和缺点，并指出所进行的主要近似。考虑的入射粒子是能量高达 150 keV 的电子和小于 300 MeV 的质子。通过适当选择横截面以及电离和激发电位，可以通过多种方式解释这些颗粒与水相互作用的液相特异性。我们的模拟代码（称为 TRACPRO 和 TRACELE）用于提供不易观察到的辐射作用中间步骤的信息。例如，确定了飞秒时间尺度上初始辐射分解物质的产率，并给出了它们的各种形成通道的相对贡献。还显示了二次电子的能量分布。 (C) 1998 年由爱思唯尔科学有限公司出版。保留所有权利。
Monte Carlo simulation techniques have been used to model the sequence of events that are generated by the interaction of ionising radiations with pure liquid water. Those events include (i) the energy depositions that occur through the ionisation and the excitation of water molecules; and (ii) the relaxation pathways and the ultrafast reactions of the subexcitation electrons, of the transient water anions and cations, and of the excited water molecules. The subsequent homogeneous and nonhomogeneous chemical reactions that take place along the radiation tracks when the radiolytic species diffuse into the medium are treated in the following paper (Frongillo ct at., 1998a). The principles and the physical laws on which our simulation codes are based are explained in some detail to identify their strengths and weaknesses and to point out the main approximations that are made. The incident particles that are considered are electrons with energies up to 150 keV and protons of less than 300 MeV. The specificity of the liquid phase for the interaction of those particles with water is accounted for in several ways, through appropriate choices of cross sections as well as ionisation and excitation potentials. Our simulation codes, called TRACPRO and TRACELE, are used to provide information on intermediate steps of the action of the radiation which are not readily observable. For example, the yields of the initial radiolytic species on the femtosecond time scale are determined and the relative contributions of their various formation channels are given. The energy distribution of the secondary electrons is also shown. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.