Hybrid CMOS detectors for the Lynx x-ray surveyor high definition x-ray imager

TL;DR

This paper discusses the development and testing of hybrid CMOS detectors with small pixels for high-resolution x-ray imaging in space missions, highlighting their low noise, high spectral resolution, and suitability for the Lynx mission.

Contribution

The paper presents new small-pixel hybrid CMOS detectors with improved noise and spectral resolution, suitable for high-resolution space-based x-ray imaging.

Findings

Achieved read noise as low as 5.4 e-

Measured energy resolution of 148 eV at 5.9 keV

Demonstrated detector applicability for Lynx HDXI

Abstract

X-ray hybrid CMOS detectors (HCDs) are a promising candidate for future x-ray missions requiring high throughput and fine angular resolution along with large field-of-view, such as the high-definition x-ray imager (HDXI) instrument on the Lynx x-ray surveyor mission concept. These devices offer fast readout capability, low power consumption, and radiation hardness while maintaining high detection efficiency from 0.2 to 10 keV. In addition, x-ray hybrid CMOS sensors may be fabricated with small pixel sizes to accommodate high-resolution optics and have shown great improvements in recent years in noise and spectral resolution performance. In particular, 12.5-{\mu}m pitch prototype devices that include in-pixel correlated double sampling capability and crosstalk eliminating capacitive transimpedance amplifiers, have been fabricated and tested. These detectors have achieved read noise as low as 5.4 e-, and we measure the best energy resolution to be 148 eV (2.5%) at 5.9 keV and 78 eV (14.9%) at 0.53 keV. We will describe the characterization of these prototype small-pixel x-ray HCDs, and we will discuss their applicability to the HDXI instrument on Lynx.