Construction of a Time-Of-Flight System for Beams Charge-Bred by using the Electron Beam Ion Source

摘要

A time-of-flight (TOF) system adopting single reflection has been constructed to identify the charge states of ions charge-bed by using the electron beam ion source (EBIS). The reflection allows for time focusing of the system in a compact manner. The EBIS under construction will enhance the charge states of rare isotopes produced by isotope separation on line (ISOL) so as to utilize the superconducting post linear accelerator efficiently. The TOF system consists of an ion-gate, reflection electrodes and multi-channel plates (MCP) detector. The maximum voltage on ions is 20 kV, and the beam optics design was performed using SIMION. In the front end of the TOF an ion gate is located to produce a single 5- to 10-ns pulse operating at a maximum voltage of ± 1 kV. The circuit of the fast switching system, which converts - 1 kV to 1 kV in a few ns, was simulated for an equivalent circuit of the gate by using LTspice. The TOF system is being fabricated and will be connected to a Cs ion source for initial beam tests with Cs~(1+)mixed with background ions.