Design of the Time of Flight ERDA system for 6 MV tandem ion accelerator

Abstract

At present, the Ion Beam Laboratory MTF STU in Trnava [1] uses the basic Ion Beam Analysis (IBA) methods, namely Rutherford Backscattering Spectrometry (RBS), Particle Induced X-ray Emission (PIXE), in limited extend Nuclear Reaction Analysis (NRA) and Elastic Recoil Detection Analysis with He beam (He ERDA). The development of the Heavy Ion Elastic Recoil Detection Analysis (HI ERDA) system for our laboratory was initiated. The supposed analysing projectiles will be from O to Au with energies ∼ 1 MeV/u. HI ERDA is ideal for measuring the depth concentration profiles of all elements lighter than the mass of the primary ions, present in near surface layers in heavy base material. During the HI ERDA experiment, the high energy heavy ions impinge on the sample at an acute angle, atoms of the sample are elastically recoiled, and their energy and mass has to be determined. We have chosen the detection system consisting of the Time of Flight (ToF) telescope in combination with silicon charge particle detectors. Two time gates will be used to acquire the two time stamps. The fast acquisition electronics has to collect the coincidence energy/ToF/yield multi parametric spectra. The proposed ToF ERDA signal processing system consists from combination of analogue nuclear electronics and the fast digital multi-parameter acquisition system. The first draft of the ToF HI ERDA for Trnava IBA laboratory is presented.