Acoustic instrumentation for a bubble chamber towards dark matter searches

M Reis,J.G Marques,A Kling,T Morlat,M Felizardo,A C Fernandes,K Coulié,P Febvre,G Micolau

doi:10.1051/e3sconf/20198801002

Abstract

Dark matter is one of the top unsolved mysteries in physics. Its existence is well-established although its nature remains unknown. Despite the progress made in the direct search effort, reflecting over 10 orders of magnitude in sensitivity since 1984, no true candidates to explain this phenomenon have appeared in searches covering a range from ~10 GeV to 1 TeV. This article reports on the development of a 1 kg freon bubble chamber prototype, including the chamber recompression system design and testing, initial acoustic detection of bubble formation, and initial neutron and alpha detector response studies. The prototype constructed was a transparent acrylic containment vessel, capable of withstanding recompression cycles to a pressure of 16 bar. The acoustic signal accompanying bubble formation was investigated using three different sensors: a low frequency microphone (Panasonic) with a flat response over 0.020-16 kHz, an ultrasound externallypolarized condenser microphone (AviSoft) with a flat response over 10-150 kHz, and an hydrophone (Reson) with a flat response over 5-170 kHz. Acoustic signatures of several induced events were successfully registered. The data acquisition digitizer used, to meet the range of the three microphones, was the NI PCI-6251 16-Bit, with at least 1.25 MSps for 1-Channel.

Highlights

In 2012, the SIMPLE Collaboration [1] imposed the most stringent SpinDependent constraint on the dark matter exclusion plot, contributing to reduce the possible window of existence of a WIMP to explain the dark matter phenomenon
SIMPLE obtained this result while working with superheated droplet detectors (SDDs) to remain competitive with other experiments in the field, it needed to increase the total active mass
The encountered solution was to substitute the SDDs in the search for dark matter, with a bubble chamber, increasing the active mass in more than 2000%

Summary

Introduction

In 2012, the SIMPLE Collaboration [1] imposed the most stringent SpinDependent constraint on the dark matter exclusion plot, contributing to reduce the possible window of existence of a WIMP (weakly interacting massive particle) to explain the dark matter phenomenon. SIMPLE obtained this result while working with superheated droplet detectors (SDDs) to remain competitive with other experiments in the field, it needed to increase the total active mass. The encountered solution was to substitute the SDDs in the search for dark matter, with a bubble chamber, increasing the active mass in more than 2000%. This article describes precisely the complete deployment, i.e., construction, instrumentation, and analysis of acoustic results from particle calibrations, of a bubble chamber detector for dark matter searches

Dark Matter

Bubble Chamber Deployment

Findings

Conclusions