A Low-Noise CMOS Pixel Direct Charge Sensor, Topmetal-II-

Abstract

We report the design and characterization of a CMOS pixel direct charge sensor, Topmetal-II-, fabricated in a standard 0.35um CMOS Integrated Circuit process. The sensor utilizes exposed metal patches on top of each pixel to directly collect charge. Each pixel contains a low-noise charge-sensitive preamplifier to establish the analog signal and a discriminator with tunable threshold to generate hits. The analog signal from each pixel is accessible through time-shared multiplexing over the entire array. Hits are read out digitally through a column-based priority logic structure. Tests show that the sensor achieved a <15e- analog noise and a 200e- minimum threshold for digital readout per pixel. The sensor is capable of detecting both electrons and ions drifting in gas. These characteristics enable its use as the charge readout device in future Time Projection Chambers without gaseous gain mechanism, which has unique advantages in low background and low rate-density experiments.

References in corpus (6)

• The detection of single electrons by means of a Micromegas-covered MediPix2 pixel CMOS readout circuit
• Gas Pixel Detectors for X-ray Polarimetry applications
• Reading a GEM with a VLSI pixel ASIC used as a direct charge collecting anode
• The Directional Dark Matter Detector
• Detector of alpha particles and x-rays operating in ambient air in pulse counting mode or/and with gas amplification
• Development of a highly pixelated direct charge sensor, Topmetal-I, for ionizing radiation imaging

Cited by in corpus (11)

• Gaseous and dual-phase time projection chambers for imaging rare processes
• Topmetal-M: a novel pixel sensor for compact tracking applications
• Neutrinoless Double Beta Decay with ${}^{82}$SeF${}_6$ and Direct Ion Imaging
• Three-dimensional convolutional neural networks for neutrinoless double-beta decay signal/background discrimination in high-pressure gaseous Time Projection Chamber
• Test of \textit{Topmetal-${II}^{-}$} In Liquid Nitrogen For Cryogenic Temperature TPCs
• Simulation Study of Energy Resolution with Changing Pixel Size for Radon Monitor Based on \textit{Topmetal-${II}^{-}$} TPC
• A beam monitor using silicon pixel sensors for hadron therapy
• A deep learning approach to multi-track location and orientation in gaseous drift chambers
• A highly pixelated CdZnTe detector based on \textit{Topmetal-${II}^{-}$} sensor
• The Selena Neutrino Experiment
• Detailed study of the column-based priority logic readout of Topmetal-II- CMOS pixel direct charge sensor