Dr Elena Popova (MEPhI)
The TUNKA EAS Cherenkov experiment operates in the Tunka Valley in Siberia. The main physics goals of the experiment are measurements of energy spectrum and mass composition of primary cosmic rays in the energy region of 10^15-10^18 eV and detection of high energy gamma-rays from supernova remnants with energy threshold of 20-50TeV. New 8" hemispherical PMTs from Hamamatsu and ET have been thoroughly studied. They are developed especially for such kind of applications and can withstand high anode current due to night sky background. In case of high energy gamma-ray detection PMTs sensitivities to Cherenkov light are increased by depositing WLS foils on PMTS.