Design of an energy analyzer for highly charged Ions HCI beams

Abstract

The measurements of the energy spread and the average beam energy for highly charged ion (HCI) beams, such as those delivered from EBIS charge breeder ion source and ECR ion source, demand the development of an energy analyzer of highest measurement efficiency. A new prototype of a compact analyzer called retarding field energy analyzer RFEA capable to handle all kinds of HCI beams at RISP project is being designed. The RFEA's efficiency measurement has been evaluated via numerical simulations. The involvements of the beam emittance and, mainly, the space charge effect to degrade the RFEA's efficiency have been simulated. The simulations showed that the developed RFEA, with its improved optics system and for optimum voltages on the focusing cylinder, may lead to high efficiency energy resolutions not exceeding 0.57 eV for beam energy going up to 20 keV . Acceptable errors on the measured energy spread not exceeding 30 % are, likewise, achieved despite the presence of degradations stemming from the previous degrading effects. The measurement of the average energy showed large shifts of some hundred eV from the theoretical average beam energy due to the overlapping of the ensemble of beamlets forming the HCI beam. The 3D design of this analyzer and its components will be also presented. The material of these components and their positioning to avoid electrical breakdowns will be also discussed.