High density aerogel for ASHIPH SND—test results

The paper is devoted to the cosmic tests of particle identification system for the SND detector at VEPP-2000. The goal of the tests is to measure main parameters of the system: average signal for the relativistic particles, nonuniformity of the light collection, and time resolution. The measurements of the average signal were done in five points of the counter. The obtained value of the signal is about 10 photoelectrons. The time resolution is about 2ns. The time dependence of the average amplitude was measured also. It was shown that average amplitude of the signal decreases with characteristic time of about two years. The cause of the signal decrease is discussed.