Development of a fast electron bremsstrahlung diagnostic system based on LYSO and silicon photomultipliers during lower hybrid current drive for tokamak

A novel real time fast electron bremsstrahlung (FEB) diagnostic system based on the lutetium yttrium oxyorthosilicate scintillators (LYSO) and silicon photomultipliers (SiPM) has been developed for tokamak. The diagnostic system is dedicated to study the FEB emission in the hard x-ray (HXR) energy range between 10 and 200 keV during the lower hybrid current drive. The system consists of a detection module and three data acquisition and processing (DAP) boards. The detection module consists of annulus LYSO-SiPM detector array and a 12-channel preamplifier module. The DAP boards upload the data to the host computer for displaying and storing through PXI bus. The time and space resolutions of the system are 10 ms and 4 cm, respectively. The experimental results can show the evolution over time and the spatial distribution of FEB. This paper presents the system performance and typical discharge results.