Restoration of the radio frequency ion source of the 5.5 MV CN-Van de Graaff accelerator at IFUNAM

Abstract

The 5.5 MV CN-Van de Graaff (VDG) accelerator was first installed and operated in the early 50's at Rice University (Houston, TX) and it was donated to IFUNAM (“Instituto de Física, Universidad Nacional Autónoma de México”) in 1984 and started a new life in 1988. At the end of 2017, the ion source was severely damaged. Several power supplies were destroyed. In this article we describe the process of restoring the VDG terminal. A number of power supplies were redesigned, built, tested and mounted in the Terminal. As a result of the work carried out during most of 2019, the VDG accelerator is now operational and we show data from the Rutherford Backscattering (RBS) analysis of a platinum coated silicon slab using the first proton and α beams. Electronic diagrams of all supplies in their new configuration are provided for the benefit of this kind of RF-Ion sources users still numerous.