Characterization of R-134A superheated droplet detector for neutron detection

TL;DR

This paper investigates the use of R-134a superheated droplet detectors for neutron detection, analyzing their response and stability through temperature-dependent nucleation parameters and a two-state model.

Contribution

It provides a detailed characterization of R-134a based SDDs, including response behavior and metastable state kinetics, which was not previously well understood.

Findings

Response varies with temperature

Identified metastable states and their kinetics

Proposed a two-state model for droplet behavior

Abstract

R-134a (C2H2F4) is a low cost, easily available and chlorine free refrigerant, which in its superheated state can be used as an efficient neutron detector. Due to its high solubility in water the R-134a based superheated droplet detectors (SDD) are usually very unstable unless the detector is fabricated using a suitable additive, which stabilizes the detector. The SDD is known to have superheated droplets distributed in a short-lived and in a relatively longer-lived metastable states. We have studied the detector response to neutrons using a 241AmBe neutron source and obtained the temperature variation of the nucleation parameters and the interstate kinetics of these droplets using a two-state model.