A next-generation medium-energy gamma-ray telescope targeting the MeV range would address open questions in astrophysics regarding how extreme conditions accelerate cosmic-ray particles, produce relativistic jet outflows, and more. One concept, AMEGO-X, relies upon the mission-enabling CMOS Monolithic Active Pixel Sensor silicon chip AstroPix. AstroPix is designed for space-based use, featuring low noise, low power consumption, and high scalability. Desired performance of the device include an energy resolution of 5 keV (or 10% FWHM) at 122 keV and a dynamic range per-pixel of 25-700 keV, enabled by the addition of a high-voltage bias to each pixel which supports a depletion depth of 500 um. This work reports on the status of the AstroPix development process with emphasis on the current version under test, version three (v3), and highlights of version two (v2). Version 3 achieves energy resolution of 10.4 +/- 3.2% at 59.5 keV and 94 +/- 6 um depletion in a low-resistivity test silicon substrate.
@article{arxiv.2501.11698,
title = {AstroPix: A Pixelated HVCMOS Sensor for Space-Based Gamma-Ray Measurement},
author = {Amanda L. Steinhebel and Regina Caputo and Daniel P. Violette and Anthony Affolder and Autumn Bauman and Carolyn Chinatti and Aware Deshmukh and Vitaliy Fadayev and Yasushi Fukazawa and Manoj Jadhav and Carolyn Kierans and Bobae Kim and Jihee Kim and Henry Klest and Olivia Kroger and Kavic Kumar and Shin Kushima and Jean-Marie Lauenstein and Richard Leys and Forest Martinez-Mckinney and Jessica Metcalfe and Zachary Metzler and John W. Mitchell and Norito Nakano and Jennifer Ott and Ivan Peric and Jeremy S. Perkins and Max R. Rudin and Taylor and Shin and Grant Sommer and Nicolas Striebig and Yusuke Suda and Hiroyasu Tajima and Janeth Valverde and Maria Zurek},
journal= {arXiv preprint arXiv:2501.11698},
year = {2025}
}