Review of the electrical design of SPIDER beam source drivers

This document is intended to support the review of the electrical design of the MITICA beam source and the upgrade of SPIDER beam source. In particular the following aspects are analyzed: o Driver configuration (geometry and material for the driver case and the combs); o RF coil material; o Connection of the RF circuit to the beam source potential. The first part of the study aims at the design of a driver configuration characterized by the lowest possible Efield at the triple junction (coil, driver case, vacuum or coil, comb, vacuum): the original design and possible alternatives are evaluated (chapters 1 and 2). The second part of the study aims at the estimation of the electrical parameters of the RF coil made of copper, stainless steel and copper-plated stainless steel , a request driven by mechanical requirements (welding stainless steel cooling circuit pipes to the RF coils) (chapter 3). The latter aspect is briefly presented and a conceptual design is proposed (chapter 3.3).