Nikezic D, Shahmohammadi Beni Mehrdad, Krstic D, Yu K N
Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong, China.
Faculty of Science, University of Kragujevac, Kragujevac, Serbia.
PLoS One. 2016 Jun 30;11(6):e0157627. doi: 10.1371/journal.pone.0157627. eCollection 2016.
Monte Carlo method has been used to determine the efficiency for proton production and to study the energy and angular distributions of the generated protons. The ENDF library of cross sections is used to simulate the interactions between the neutrons and the atoms in a polyethylene (PE) layer, while the ranges of protons with different energies in PE are determined using the Stopping and Range of Ions in Matter (SRIM) computer code. The efficiency of proton production increases with the PE layer thickness. However the proton escaping from a certain polyethylene volume is highly dependent on the neutron energy and target thickness, except for a very thin PE layer. The energy and angular distributions of protons are also estimated in the present paper, showing that, for the range of energy and thickness considered, the proton flux escaping is dependent on the PE layer thickness, with the presence of an optimal thickness for a fixed primary neutron energy.
蒙特卡罗方法已被用于确定质子产生的效率，并研究产生的质子的能量和角分布。使用ENDF截面库来模拟中子与聚乙烯（PE）层中原子之间的相互作用，而使用“物质中离子的阻止本领和射程”（SRIM）计算机代码来确定不同能量的质子在PE中的射程。质子产生的效率随PE层厚度的增加而提高。然而，除了非常薄的PE层外，从一定体积的聚乙烯中逸出的质子高度依赖于中子能量和靶厚度。本文还估计了质子的能量和角分布，结果表明，在所考虑的能量和厚度范围内，逸出的质子通量取决于PE层厚度，对于固定的初级中子能量存在一个最佳厚度。
