Speaker
Hiroki ROKUJO
(Nagoya University)
Description
Gamma-Ray Astro-Imager with Nuclear Emulsion (GRAINE) is a project of cosmic gamma-ray observation using a balloon-borne emulsion detector. The angular resolution of the emulsion gamma-ray telescope (0.08$^{\circ}$ @ 1-2 GeV) is one order of magnitude better than that of the Fermi-LAT. In addition, it has the polarization sensitivity using the pair creation mode. GRAINE aims at high-resolution imaging of SNRs and point sources in the Galactic plane/center and the polarimetry in the unexplored subGeV/GeV region, by long duration balloon flights with large aperture area telescopes ($\sim$10 m$^{2}$). In 2015 May, GRAINE 2nd balloon-borne experiment is conducted in Australia to detect well-known bright gamma-ray source, Vela pulsar, and to demonstrate the performance of the emulsion telescope. The aperture area is 3600 cm$^{2}$ and the flight duration is $\sim$24 hours.
We adopted and developed a balloon-style pressure vessel for GRAINE 2015. The entire emulsion telescope is contained in a pressure vessel pressurized to $\sim$0.2 atm to maintain the vacuum-packed emulsion chamber at balloon altitudes. It consists of aluminum rings, two hemispherical rubber films, and shells made of plastic fabric, which reduces the absorbance of signals and the backgrounds caused secondary interaction at the surface of the vessel.
We present a balloon-style pressure vessel and the flight performance in GRAINE balloon-borne experiment in 2015.
| Registration number following "ICRC2015-I/" | 846 |
|---|---|
| Collaboration | -- not specified -- |
Author
Hiroki ROKUJO
(Nagoya University)
Co-author
GRAINE collaboration
(GRAINE collaboration)
