The Green’s function method was applied to solve the one-dimensional positron diffusion equation for a system consisting of up to four layers that contain defects with different trapping rates. These allow us to obtain the analytical relationships valid for the evaluation of data obtained from variable energy positron measurements. They have been implemented in user-friendly free computer code available to users. Fitting strategies are presented to extract the relevant physical parameters. The code was used to determine positron diffusion length in samples of polycrystalline pure, well-annealed iron, depleted uranium, and titanium.

Program summary

Program Title: e+DSC-1

CPC Library link to program files: https://doi.org/10.17632/jxpj25kjvr.1

Licensing provisions: MIT license

Programming language: Microsoft Visual Basic 2015

External routines/libraries: Accord.NET

Nature of problem: The program enables the analysis of data obtained from a variable energy positron beam. The shape parameter of the annihilation line as a function of the incident positron energy is evaluated using a positron diffusion trapping model in which the positron trapping rate function is expressed as a four-step function.

Solution method: The one-dimensional diffusion equation was solved by the Green’s function method. This allows the use of an exact form for the positron implantation profile, which is used in the program as the Makhov’s function. The parameters of this function are obtained from the MC simulation with GEANT4 and stored in the program.

中文翻译：

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使用e分析正电子分析数据${}^{+}$DSc电脑程式码

格林函数法用于求解一维正电子扩散方程，该系统由最多四层组成的系统组成，这些四层包含具有不同俘获率的缺陷。这些使我们能够获得对从可变能量正电子测量获得的数据进行评估有效的分析关系。它们已通过用户可用的用户友好的免费计算机代码实现。提出了拟合策略来提取相关的物理参数。该代码用于确定多晶纯，退火良好的铁，贫铀和钛样品中的正电子扩散长度。

计划摘要

节目名称：e + DSC-1

CPC库链接到程序文件：https://doi.org/10.17632/jxpj25kjvr.1

许可条款：MIT许可

编程语言： Microsoft Visual Basic 2015

外部例程/库：  Accord.NET

问题性质：该程序可以分析从可变能量正电子束获得的数据。使用正电子扩散俘获模型评估evaluated灭线的形状参数作为入射正电子能量的函数，在该模型中，将正电子俘获速率函数表示为四步函数。

求解方法：一维扩散方程通过格林函数法求解。这允许使用正电子注入轮廓的精确形式，该形式在程序中用作Makhov函数。该功能的参数是通过使用GEANT4进行的MC仿真获得的，并存储在程序中。