The path toward 500 $\mu$m depletion of AstroPix, a pixelated silicon HVCMOS sensor for space and EIC

TL;DR

This paper discusses the development of AstroPix, a pixelated silicon HVCMOS sensor for space applications, focusing on achieving 500 μm depletion to enhance energy sensitivity for gamma-ray detection.

Contribution

It presents the current status of depletion measurements of AstroPix, including laser scanning and simulation validation, advancing the sensor's development for space use.

Findings

Depletion measurements align with simulations.

Laser scanning confirms sensor depletion status.

Progress toward 500 μm depletion for improved energy sensitivity.

Abstract

The precise reconstruction of Compton-scatter events is paramount for an imaging medium-energy gamma-ray telescope. The proposed AMEGO-X is enabled by a silicon tracker utilizing AstroPix chips - a pixelated silicon HVCMOS sensor novel for space use. To achieve science goals, each 500 x 500 $\mu$m$^2$ pixel must be sensitive for energy deposits ranging from 25 - 700 keV with an energy resolution of 5 keV at 122 keV (< 10%). This is achieved through depletion of the 500 $\mu$m thick sensor, although complete depletion poses an engineering and design challenge. This work will summarize the current status of depletion measurements highlighting direct measurement with TCT laser scanning and the agreement with simulation. Future plans for further testing will also be identified.