The flight of the GAPS prototype experiment

TL;DR

The GAPS prototype flight demonstrated the performance of its subsystems and background measurement capabilities, validating the detector concept for future dark matter searches using low-energy cosmic ray antideuterons.

Contribution

This work provides the first successful prototype flight of the GAPS detector, testing its subsystems, calibration methods, and background measurements for future dark matter detection missions.

Findings

Successful demonstration of GAPS detector subsystems in flight

Calibration of tracker modules and timing subsystem achieved

Background levels of atmospheric and cosmic X-rays measured

Abstract

The General AntiParticle Spectrometer experiment (GAPS) is foreseen to carry out a dark matter search using low-energy cosmic ray antideuterons at stratospheric altitudes with a novel detection approach. A prototype flight from Taiki, Japan was carried out in June 2012 to prove the performance of the GAPS instrument subsystems (Lithium-drifted Silicon tracker and time-of-flight) and the thermal cooling concept as well as to measure background levels. The flight was a success and the stable flight operation of the GAPS detector concept was proven. During the flight about $10^6$ charged particle triggers were recorded, extensive X-ray calibrations of the individual tracker modules were performed by using an onboard X-ray tube, and the background level of atmospheric and cosmic X-rays was measured. The behavior of the tracker performance as a function of temperature was investigated. The tracks of charged particle events were reconstructed and used to study the tracking resolution, the detection efficiency of the tracker, and coherent X-ray backgrounds. A timing calibration of the time-of-flight subsystem was performed to measure the particle velocity. The flux as a function of flight altitude and as a function of velocity was extracted taking into account systematic instrumental effects. The developed analysis techniques will form the basis for future flights.