The Compton Spectrometer and Imager (Cosi) Project
CHIEN-YING, YANG2*, S, Boggs1, H-K, Chang2, P, Jean3, for the COSI Collaboration1,2,3,4,5,6,7
1Space Sciences Laboratory, University of California, Berkeley, Berkeley, USA
2Institute of Astronomy, National Tsing Hua University, HsinChu, Taiwan
3The Research Institute in Astrophysics and Planetology (IRAP), Toulouse, France
4Lawrence Berkeley National Laboratory, Berkeley, USA
5Institute of Physics, Academica Sinica, Taipei, Taiwan
6Department of Physics, National Central University, Chungli, Taiwan
7National Nano Device Laboratories (NDL), National Atmospheric Research Laboratory, HsinChu, Taiwan
* presenting author:Chien-Ying Yang,

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 cross-strip germanium detectors, each with 15mm x 80mm x 80mm dimension and full 3D position resolution of less than 2 mm³. 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 were conducted in the past. The most recent flight was launched from Wanaka, New Zealand, in May with a super-pressure balloon flying for 47 days. During this flight, COSI discovered GRB160530A. The COSI collaboration is now working for the next flight in spring 2018, to launch again from Wanaka, New Zealand, for a 100-day flight. We will report the COSI 2016 flight and its current status. COSI is a join
effort of several institutions in Taiwan, US and France.

Keywords: Compton telescope, gamma-ray, Gamma-ray burst, Germanium detector