GRAINE 2018 experiment: Performance evaluation of gamma-ray telescope utilizing nuclear emulsion
2019 November 14
2019 November 21
The observation of cosmic gamma-rays is crucial to understanding high-energy astrophysical phe- nomena. The Gamma-Ray Astro-Imager with Nuclear Emulsion (GRAINE) aims to precisely ob- serve gamma-ray sources with a balloon-borne gamma-ray telescope utilizing nuclear emulsion, which is a three-dimensional tracking detector with a sub-micron spatial resolution. We launched the third balloon experiment, GRAINE 2018, on April 26, 2018 as a demonstration project. The flight was successful, data acquisition was completed, and we are analyzing the data now. We evaluated the angular resolution for gamma-rays in the 100-300 MeV energy region of the con- verter’s flight data, and it is 0.57◦ (tanθ ≃zenith angle<0.5), 0.81◦ (0.5<tanθ <1.0). This is better than the required performance value, which is 1.0◦ in 100- MeV energy region.