Method of incident low-energy gamma-ray direction reconstruction in the GAMMA-400 gamma-ray space telescope

摘要

The GAMMA-400 gamma-ray space-based telescope has as its main goals to measure cosmic y-ray fluxes and the electron-positron cosmic-ray component produced, theoretically, in dark-matter-particles decay or annihilation processes, to search for discrete y-ray sources and study them in detail, to examine the energy spectra of diffuse y-rays - both galactic and extragalactic - and to study gamma-ray bursts (GRBs) and y-rays from the active Sun. Scientific goals of GAMMA-400 telescope require fine angular resolution. The telescope is of a pair-production type. In the converter-tracker, the incident gamma-ray photon converts into electron-positron pair in the tungsten layer and then the tracks are detected by silicon-strip position-sensitive detectors. Multiple scattering processes become a significant obstacle in the incident-gamma direction reconstruction for energies below several gigaelectronvolts. The method of utilising this process to improve the resolution is proposed in the presented work.