A Fast High-Voltage Switching Multiwire Proportional Chamber

TL;DR

This paper introduces a novel high-voltage switching multiwire proportional chamber designed for high-rate particle detection, featuring dynamic gain control to mitigate space charge effects, suitable for experiments like DeeMe at J-PARC.

Contribution

It presents a new detector scheme with a dynamic gain control technique that enhances performance under high instantaneous hit rates.

Findings

Successfully reduced space charge effects in high-rate conditions

Verified detector operation with large prompt particle pulses

Achieved reliable single-electron detection in challenging environments

Abstract

A new experiment, called DeeMe, which is designed to search for $\mu$-e conversions with a sensitivity of $\mathcal{O}(10^{-14})$, is in preparation at the Japan Proton Accelerator Research Complex (J-PARC). It utilizes a high-quality pulsed proton beam from the Rapid Cycling Synchrotron at J-PARC. The detector for DeeMe must tolerate large pulses of prompt charged particles whose instantaneous hit rate is as large as 70 GHz/mm$^2$ in a time width of 200 ns and detect a single electron that arrives with delayed timing on the order of microseconds. A special wire chamber has been developed with a new dynamic gain control technique that reduces space charge effects. In this paper, we detail the novel detector scheme and operation verification.