Phase transition time delays in irradiated superheated superconducting granules

TL;DR

This study investigates the timing characteristics of phase transitions in irradiated superheated superconducting granules, revealing material-dependent differences in transition time distributions for nuclear recoil and ionizing events.

Contribution

It provides the first detailed analysis of phase transition time delays in Zn and Sn superheated superconducting granules under neutron and proton irradiation.

Findings

Sn granules show narrow, energy-independent transition time distributions.

Zn granules exhibit broader, energy-dependent transition time distributions.

The results enhance understanding of timing in superheated superconducting granule detectors.

Abstract

The time difference between a particle interaction in a Superheated Superconducting Granule (SSG) and the resulting phase transition signal has been explored. Detectors containing Zn and Sn SSG were irradiated with neutrons and protons to study the heating mechanism taking place in nuclear recoil and ionizing events. Scattered neutrons have been detected by a scintillator hodoscope behind the SSG with a recoil energy measurement resolution of 10% and an interaction time resolution of 1ns. The fast transition of the metastable granules allowed to determine the elapsed time between an energy deposition and the phase transition signal. In the case of Sn granules, the results show that the time distributions are narrow and independent of the deposited energy in nuclear recoil and ionizing events. In Zn, however, the time distributions are much broader and depend on the energy deposition in the granule.