ИСТИНА

The further progress in studying of cosmic rays of high and ultrahigh energy is substantially connected with more detailed studying of structure of an energy spectrum (a "knee" close energy 3*10^15 eV, feature in energy area 10^19 eV, a problem of "relic trimming" in energy area 10^20 eV, it is possible also existence of more thin structure of a spectrum in other areas in this energy range). The goal of experiment SPHERE was studying of structure of energy spectrum in energy area above 10^15 - 10^16 eV. One of the most adequate calorimetric techniques of measurement of energy of particles in this area energy is measurement of an integrated stream of cherenkov light of EAS. Preliminary results of the measurements which have been carried out in February - March, 2000 in area of Vol'sk city are presented. Measurements were carried out using of a new method of registration of Cherenkov light of EAS reflected from a snow surface. Experimental array SPHERE was lifted with the help of a fastened balloon on altitude of 1 km.