Design and performance of an ionisation chamber for the measurement of low alpha-activities

TL;DR

This paper presents the design and testing of a new radio-pure ionisation chamber optimized for low alpha-activity measurements, utilizing pulse shape analysis to reduce background noise and improve detection sensitivity.

Contribution

It introduces a novel ionisation chamber constructed from radio-pure materials with demonstrated low background rates for long-lived alpha-decay detection.

Findings

Achieved background rate of 10.9 counts/day in 1-9 MeV range

Used pulse shape analysis to discriminate signal from background

Operated successfully over 30.8 days

Abstract

A new ionisation chamber for alpha-spectroscopy has been built from radio-pure materials for the purpose of investigating long lived alpha-decays. The measurement makes use of pulse shape analysis to discriminate between signal and background events. The design and performance of the chamber is described in this paper. A background rate of ($10.9 \pm 0.6$) counts per day in the energy region of 1 MeV to 9 MeV was achieved with a run period of 30.8 days. The background is dominantly produced by radon daughters.