Effective exploitation of a geyser bubble-chamber equipment as a background-free fast neutron detector

TL;DR

This paper demonstrates how a geyser-concept bubble-chamber, originally designed for dark matter detection, can be effectively repurposed as a background-free fast neutron detector with validated efficiency and practical applications.

Contribution

The study adapts MOSCAB geyser bubble-chamber technology for fast neutron detection, establishing background-free operation above 2.5 MeV and validating detection efficiency through simulations and experiments.

Findings

Detector operates background-free above 2.5 MeV neutron energy.

Detection efficiency functions are validated experimentally.

Potential for measuring weak neutron sources and cosmic ray monitoring.

Abstract

MOSCAB equipment, a geyser-concept bubble-chamber originally thought for the search of dark matter in the form of WIMPs, is employed for the detection of fast neutrons. Once the background-free operating conditions are determined such that the detector is sensitive only to neutrons, which occurs when the neutron energy threshold required for nucleation is higher than approximately 2.5 MeV, the detector response to fast neutrons is investigated using an AmBe neutron source. Sets of detection efficiency functions are then produced via Monte Carlo simulations and post-processing, their validation being performed experimentally and discussed. Finally, the use of the detector to measure the fast neutron activity of very weak n-sources in clean environments, as well as to monitor the cosmic ray variations through the neutron component of the Extensive Air Showers, is considered.