GRAINE project and first results on 2018 balloon-borne experiment
2019 July 22
We are developing GRAINE project, 10 MeV -- 100 GeV cosmic $\gamma$-ray observations with a precise (0.08 degree @ 1 -- 2 GeV) and polarization sensitive large-aperture-area ($\sim$10 m$^2$) emulsion telescope by repeating long duration balloon flights. In April 2018, we performed a balloon-borne experiment with various developments, improvements and preparations, and with a 0.38 m$^2$ aperture and 17.4 hour flight duration in Australia to demonstrate overall performance of the telescope with a detection and imaging of a known $\gamma$-ray source, Vela pulsar. In 2021 or later, with a 10 m$^2$ and $>\sim$24 hour flight duration, we aim to start scientific observations.