FIELD: recording of nuclear radiations and design of track detectors of charged particles,. SUBSTANCE: temperature of central part of chamber bottom is set below melting temperature or sublimation temperature of steam forming substance. In this case temperature difference between walls and central part of bottom amounts to 5-80 C. Metal cylinder is slide-fitted in central hole of chamber bottom. Heater and trough for steam forming substance have thermal contact and are attached to cover of chamber. EFFECT: enhanced operational reliability. 9 cl, 1 dwg
