Measurement of Cosmic Ray Nuclei with GRAINE2015
2017 August 16
GRAINE(Gamma Ray Astro-Imager with Nuclear Emulsion) experiment consists of a balloon borne emulsion chamber and emulsion film shifting system launched on May 6, 2015 in Australia and its acceptance and flight duration is 3780m$^2$ sr and 14 hours at 37 km above sea level, respectively. The main scientific goals of GRAINE2015 are the precise measurement of sub GeV gamma-rays from Vela pulsar, the measurement of charm particle production cross section at high altitude in the air and the study of cosmic ray nuclei compositions. The nuclear emulsion films used in GRAINE2015 will be able to measure cosmic ray nuclei from hydrogen nuclei to more than iron nuclei. The measurement of the chemical composition of cosmic ray nuclei in the MeV-TeV energy range will reveal new insights about the cosmic ray nuclei life in the our galaxy, from their origin to the propagation in the interstellar medium. The Cosmic ray nuclei absolute charge Z is measured along the trajectory in the GRAINE2015 emulsion films by using high speed emulsion track selector (HTS). This allows to scan the entire emulsion film within the zenith angle less than 63 degree. The charge measurement methods in HTS scan data are here explained, and their performance presented.