Accelerator-Based Analysis of Rough Wall Materials From Fusion Devices

Abstract: Time of Flight - Elastic recoil detection analysis (ToF-ERDA) is a method used to analyse the composition of wall samples from fusion devices. All current analysing software for ToF-ERDA assumes that the target is perfectly flat which could create inaccuracies when rough surfaces are analysed. The aim of this project was to get a better understanding of how the roughness of samples from fusion devices affect the results from ToF-ERDA. To investigate this, three existing simulation softwares SIMNRA, TRIM and Potku were used. Programs were developed in order to use these to simulate three different targets with varying roughness, which were modelled as a combination of surfaces of different thicknesses. The results from which were put back into Potku where the differences between the targets could be noted. The study shows that it was possible to apply roughness to the already existing programs and showed similarities between the resulting depth profiles. When applying roughness, the concentration of surface elements decreased at the top of the layer but also went further into the sample.