English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We have developed large-area lithium-drifted silicon (Si(Li)) detectors tomeet the unique requirements of the General Antiparticle Spectrometer (GAPS)experiment. GAPS is an Antarctic balloon-borne mission scheduled for the firstflight in late 2020. The GAPS experiment aims to survey low-energy cosmic-rayantinuclei, particularly antideuterons, which are recognized as essentiallybackground-free signals from dark matter annihilation or decay. The GAPS Si(Li)detector design is a thickness of 2.5 mm, diameter of 10 cm and 8 readoutstrips. The energy resolution of <4 keV (FWHM) for 20 to 100 keV X-rays attemperature of -35 to -45 C, far above the liquid nitrogen temperaturesfrequently used to achieve fine energy resolution, is required. We developed ahigh-quality Si crystal and Li-evaporation, diffusion and drift methods to forma uniform Li-drifted layer. Guard ring structure and optimal etching of thesurface are confirmed to suppress the leakage current, which is a main sourceof noise. We found a thin un-drifted layer retained on the p-side effectivelysuppresses the leakage current. By these developments, we succeeded indeveloping the GAPS Si(Li) detector. As the ultimate GAPS instrument willrequire >1000 10-cm diameter Si(Li) detectors to achieve high sensitivity torare antideuteron events, high-yield production is also a key factor for thesuccess of the GAPS mission.

Development of Large-area Lithium-drifted Silicon Detectors for the GAPS Experiment