DESIGN OF HIGH DYNAMIC RANGE PREAMPLIFIERS FOR A DIAMOND-BASED RADIATION MONITOR SYSTEM

Regardless of the different accelerator types (light sources like FELs or synchrotrons, high energy colliders), diagnostics is an essential el- ement for both personnel and machine protection. With each up- date, accelerators become more complex and require an appropriate diagnostic system capable of satisfying multiple specifications, that be- come more stringent as complexity increases. This paper presents pro- totyping work towards a possible update of the readout electronics of a system based on single-crystal chemical vapor deposition (scCVD) di- amond sensors, monitoring the radiation dose-rates in the interaction region of SuperKEKB, an asymmetric-energy electron-positron collider. The present readout units digitize the output signals from the radia- tion monitors, process them using an FPGA, and alert the accelerator control system if the radiation reaches excessive levels. The proposed updated version introduces a new design for the analog front end that overcomes its predecessor’s limits in dynamic range thanks to high- speed switches to introduce a variable gain in transimpedance pream- plifiers, controlled by an ad-hoc developed FPGA firmware.