Design of analog circuit of photomultiplier tube array for wide field of view Cherenkov telescope array of LHAASO

Abstract

The wide field of view Cherenkov telescope array (WFCTA) of the Large High Altitude Air Shower Observatory (LHAASO) is intended to detect atmospheric Cherenkov light or fluorescence. The photomultiplier tube (PMT) array is designed to enable atmospheric monitoring in real time and telescope calibration. This paper introduces the design of the analog circuit for the PMT array. The analog board has 16 channels, where each channel contains a shaping circuit, a high gain circuit and a low gain circuit. The shaping circuit uses a charge integrating circuit, and the amplifier module is composed of a noninverting amplifier circuit and a full differential amplifier circuit. Test results indicate that the dynamic range of the designed circuit is more than 3.2 orders of magnitude, the small signal resolution is less than 20%, the corresponding resolution of large signals is less than 4%, and the relative deviation from linearity is less than 5%. These performance indicators exceed the requirements of the project.