Speaker
Field Rogers
(MIT)
Description
Novel large-area lithium-drifted silicon (Si(Li)) detectors have been developed for the General Antiparticle Spectrometer (GAPS) Antarctic balloon mission. GAPS will search for antinuclei signatures of dark matter using a novel detection technique based on exotic atom capture and decay. As the GAPS instrument will require ~10 square-meters of instrumented silicon in order to achieve sensitivity to rare antideuteron events, the successful development of a novel high-yield fabrication process has been critical. We demonstrate here that the resulting 10 cm-diameter, 2.5 mm-thick, 8-strip detectors provide the necessary <4 keV (FWHM) energy resolution for X-rays and <10% energy resolution for heavy particle tracks, while operating in conditions (~−40 C and ~1 Pa) achievable on a long-duration balloon carrying a large-acceptance detector payload. Mass production and calibration of >1000 detectors has begun for the first GAPS flight, scheduled for late 2021. The detectors, while developed specifically for GAPS, have other potential applications, e.g., in heavy nuclei identification at rare isotope facilities such as NSCL/FRIB. Leveraging the success of the Si(Li) development program to further improve detector cost, X-ray resolution, and tracking efficiency would open the door to drastically improved sensitivity to cosmic antiprotons, antideuterons, and antihelium as signatures of dark matter.
Primary author
Kerstin Perez
(Massachusetts Institute of Technology)
