Design of IMPix-S3, a pixel readout sensor for future gaseous detectors at HIAF

Abstract

As the High-Intensity Heavy-ion Accelerator Facility (HIAF) advances towards higher brightness, the demand for high count rates in physics experiments becomes increasingly critical. To address the requirement of high count rates in gaseous detectors, we proposed a pixel readout sensor, IMPix-S3, which can measure energy, time and position. The IMPix-S3, fabricated in 130 nm CMOS technology, consists of a pixel array of 2 × 128 pixels, two TDC arrays of 1 × 128 TDCs, and a digital control and readout circuit. The chip features an energy measurement range from 1 ke${}^{-}$ to 20 ke${}^{-}$, an Integral Non-Linearity (INL) of only 0.176%, and an Equivalent Noise Charge (ENC) of no more than 41e${}^{-}$. It employs a coarse-fine TDC and optimizes the front-end circuit design to achieve a timing accuracy of 7 ns. This paper will discuss the design and performance of this IMPix-S3 sensor.