Development of a low-alpha-emitting {\mu}-PIC for NEWAGE direction-sensitive dark-matter search

TL;DR

This paper reports the development and testing of a low-alpha-emitting {IG} for the NEWAGE dark-matter search, aiming to reduce background noise from radioactive contaminants in the detector.

Contribution

The study introduces a new low-alpha-emitting {IG} and measures its surface alpha-ray emission rate in a mine environment, improving detector performance.

Findings

Reduced alpha-ray emission rate of the new {IG}

Successful measurement of alpha emissions in a mine environment

Enhanced suitability for dark-matter detection

Abstract

NEWAGE is a direction-sensitive dark-matter-search experiment that uses a micro-patterned gaseous detector, or {\mu}-PIC, as the readout. The main background sources are {\alpha}-rays from radioactive contaminants in the {\mu}-PIC. We have therefore developed a low-alpha-emitting {\mu}-PICs and measured its performances. We measured the surface {\alpha}-ray emission rate of the {\mu}-PIC in the Kamioka mine using a surface {\alpha}-ray counter based on a micro TPC.