标题： 使用低能电子加速器的慢正电子生成模拟 显示英文标题

标题： Simulations of slow positron production using a low energy electron accelerator

摘要： 通过高能电子与固体靶相互作用产生慢正电子的蒙特卡罗模拟已经完成。 模拟的目的是确定来自低能量、高电流电子加速器的预期慢正电子束强度。 通过模拟（a）钽电子-正电子转换器产生的快正电子以及（b）在钨慢化器中的正电子深度沉积分布，估算了每个入射电子的慢正电子产生概率。 将计算结果归一化到目前AIST LINAC测得的慢正电子产率，确定了作为能量函数的预期慢正电子产率。 对于电子束能量5 MeV（10 MeV）和电流240 $\mu$A（30 $\mu$A），预测了强度为5 $\times$ 10$^{6}$ s$^{-1}$ 的慢正电子束。 模拟还计算了每个电子在转换器中沉积的平均能量，从而可以估计给定电子能量和电流下的束流加热情况。 对于低能量、高电流运行，可获得的最大正电子束强度将受到此束流加热的限制。 显示英文摘要

摘要： Monte Carlo simulations of slow positron production via energetic electron interaction with a solid target have been performed. The aim of the simulations was to determine the expected slow positron beam intensity from a low energy, high current electron accelerator. By simulating (a) the fast positron production from a tantalum electron-positron converter and (b) the positron depth deposition profile in a tungsten moderator, the slow positron production probability per incident electron was estimated. Normalizing the calculated result to the measured slow positron yield at the present AIST LINAC the expected slow positron yield as a function of energy was determined. For an electron beam energy of 5 MeV (10 MeV) and current 240 $\mu$A (30 $\mu$A) production of a slow positron beam of intensity 5 $\times$ 10$^{6}$ s$^{-1}$ is predicted. The simulation also calculates the average energy deposited in the converter per electron, allowing an estimate of the beam heating at a given electron energy and current. For low energy, high-current operation the maximum obtainable positron beam intensity will be limited by this beam heating.