Performance of large area Micro Pixel Chamber

TL;DR

This paper introduces a large-area Micro Pixel Chamber (micro-PIC), a novel gaseous 2D imaging detector with high energy resolution and stable operation, suitable for X-ray, gamma ray, and charged particle imaging applications.

Contribution

Development of a large-area micro-PIC with high pixel density, stable operation, and capabilities for primary electron direction measurement, advancing gaseous detector technology.

Findings

Achieved 30% energy resolution at 5.9 keV

Gas gain of 7000 with argon ethane mixture

Stable operation over 65 hours despite discharges

Abstract

A novel gaseous two-dimensional imaging detector "Micro Pixel Chamber (micro-PIC)" has been developed. This detector is based on double sided printed circuit board (PCB). We have developed large area (10cm x 10cm) micro-PICs with 65536 pixel anodes of 400um pitch on a 100um thick insulating substrate. Achieved energy resolution was 30% (FWHM) at 5.9keV, and a gas gain of 7000 was obtained with argon ethane (8:2) gas mixture. This gain is high enough to detect minimum ionizing particles with such a small electrode pitch. Although several discharges occurred during 65 hours continuous operation, the detectors have kept stable operation with high gain. The micro-PIC is a useful detector for many applications e.g. X-ray, gamma ray, and charged particle imaging. The micro electrode structure allows us to measure directions of primary electrons due to incident X-rays or gamma rays, which provide a strong method for X-ray polarimetry and gamma-ray imaging.