Design and Simulation of Novel Gated Integrator for the Heavy ion Beam Monitors System

In this study, the objective is to realize a Gated Integrator (GI) circuit for silicon strip, Si(Li), CdZnTe and CsI detectors etc. With the development of radioactive ion beam physics, heavy-charged particles like carbon ions have been applied to the treatment of deep-seated inoperable tumors in the therapy terminal of the Heavy ion Research Facility in Lanzhou (HIRFL) located at the Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS). A high resolution current measurement circuit was developed to monitor the beam current at 1pA range. The circuit consisted of a low current high sensitivity I/V converter and gated integrator in an energy spectroscopy. A low offset voltage precision amplifier and new guarding and shielding techniques were used in the I/V converter circuit which allowed to measure low current. This paper will show a MOS switch configuration which is used to prevent leakage current and novel technique to compensate a charge injection in the reset switch.