Compact IH-APF type linac for PIXE and RBS analyses

Abstract

We studied an IH-APF type linac for PIXE and RBS analyses use. The compact ( L=1.5 m) linac accelerates protons from 40 keV to 2.0 MeV. This alternating-phase-focus (APF) system cannot focus such a high intense beam, but a beam of several 100 μA is focused by the combination of Focus–Defocus sequence. For PIXE and RBS analyses, intensity of bombard particles is several μA lower than several 100 μA. From particle orbit calculation, on energy width of ±0.2%, this linac can accept transverse emittance of 113 πmm mrad, longitudinal phase of 35° (by using two bunchers, beam transmission gets larger than 80%) and beam intensity of several 100 μA. The linac can accelerate protons to 2.0 MeV by RF power of about 10 kW. We designed the interdigital H (IH) linear accelerator by particle-orbit calculation. All PIXE and RBS analyses systems occupy only 2 m × 3 m. A half-model cavity was designed. The model is being manufactured now for measurement of RF characteristics.