Oral Presentation

A next-generation Compton telescope - The Compton Spectrometer and Imager (COSI)

Author(s): Hsiang-Kuang Chang (NTHU) for the COSI Collaboration

Presenter: Hsiang-Kuang Chang (National Tsing Hua University)

The Compton Spectrometer and Imager (COSI) project is an effort to develop the next generation Compton telescope of higher sensitivity. COSI is currently a balloon-borne telescope project. The heart of COSI is an array of 12 cross-strip germanium detectors, each with 15mm x 80mm x 80mm dimension and full 3D position resolution of less than 2 mm^3. COSI performs Compton spectroscopic imaging in the 0.2-10 MeV gamma-ray band with a field of view about 50 degrees across and capability of polarization measurement. It is also well suitable for monitoring transient events. Several COSI balloon flights have been conducted. The most recent flight was launched from Wanaka, New Zealand, in May 2016 with a super-pressure balloon flying for 47 days. During this flight, COSI discovered GRB160530A and detected several sources, including the 511-keV emission from the galactic center, the Crab, Cen A, and Cyg X-1. The COSI collaboration is now working for the next flight in spring 2019, to launch again from Wanaka, New Zealand, for a 100-day flight. I will report the current status of the COSI project. COSI is a join effort of several institutions in Taiwan, US and France.