# Evaluation of Kyoto's Event-Driven X-ray Astronomical SOI Pixel Sensor with a Large Imaging Area

## TL;DR

This paper evaluates the performance of a large-area, event-driven SOI pixel sensor for X-ray astronomy, demonstrating successful imaging, spectral measurement, and noise performance in a new sensor prototype.

## Contribution

It presents the development and successful testing of XRPIX5b, the largest SOI pixel sensor with event-driven readout for X-ray astronomy.

## Key findings

- Successful X-ray spectra from all pixels
- Readout noise of 46 e- (rms) in frame mode
- Effective X-ray imaging in event-driven mode

## Abstract

We have been developing monolithic active pixel sensors, named ``XRPIX'', based on the silicon-on-insulator (SOI) pixel technology for future X-ray astronomy satellites. XRPIX has the function of event trigger and hit address outputs. This function allows us to read out analog signals only of hit pixels on trigger timing, which is referred to as the event-driven readout mode. Recently, we processed ``XRPIX5b'' with the largest imaging area of 21.9~mm $\times$ 13.8~mm in the XRPIX series. X-ray spectra are successfully obtained from all the pixels, and the readout noise is 46~e$^-$~(rms) in the frame readout mode. The gain variation was measured to be 1.2\%~(FWHM) among the pixels. We successfully obtain the X-ray image in the event-driven readout mode.