Study of gamma ray response of R404A superheated droplet detector using a two-state model

TL;DR

This study investigates the gamma ray response of R404A superheated droplet detectors using a two-state model, analyzing threshold temperatures and efficiency variations to improve understanding of their gamma insensitivity and detection capabilities.

Contribution

It introduces a two-state model to describe gamma ray detection efficiency and transition kinetics in R404A SDDs, comparing experimental results with theoretical predictions.

Findings

Gamma ray threshold temperature identified and compared with theory

Detection efficiency increases with temperature above threshold

Two-state model effectively describes transition kinetics

Abstract

The superheated droplet detector (SDD) is known to be gamma insensitive below a threshold temperature which made them excellent candidates for neutron detection in the presence of gamma rays. Above the threshold temperature, the gamma ray detection efficiency increases with increase in temperature. In this work the gamma ray threshold temperature has been studied for SDD using R404A as the active liquid and is compared to the theoretical prediction. The temperature variation of gamma ray detection efficiency and interstate transition kinetics has also been studied using a two-state model. The experiments are performed at the ambient pressure of 1 atmosphere and in the temperature range of 17-32oC using a 662 keV 137Cs gamma ray source.