Speaker
Hiroki ROKUJO
(Nagoya University)
Description
Nuclear emulsion is a high resolution 3D tracking device. 0.2 $\mu$m AgBr crystals penetrated by a charged particle grow into 0.8 $\mu$m silver grains which can be observed as a track by a microscope via chemical development process. The recent fully automated readout systems enabled not only high resolution measurements but also large-scale experiments (accelerator experiments, balloon-borne experiments, cosmic ray muon radiography, and so on).
Since 2010, circumstances of the emulsion detector has drastically changed. We have introduced a system of nuclear emulsion gel production to the laboratory in Nagoya University, Japan, and have started self-development and supply of the new, ambitious gel, instead of the photographic film companies. We have also developed a next-generation readout system, Hyper Track Selector (HTS). The scanning speed is designed to 0.9 m$^{2}$/h (100 times faster than that of the current system).
Gamma-Ray Astro-Imager with Nuclear Emulsion (GRAINE) is a project of cosmic gamma-ray observation using the 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. Search for exotic particles and measurement of short-lived particle production rate in cosmic rays at balloon altitudes will be also conducted. In the GRAINE 2nd balloon-borne experiment in 2015 May, 50 m$^{2}$ of the new high sensitive emulsion films are used for the middle-scale gamma-ray telescope (aperture area 3600 cm$^{2}$) which we demonstrate the imaging performance by.
We present the status of the latest emulsion detector and readout system based on results of performance tests conducted for the 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)
