LARGE-AREA HIGH-EFFICIENCY TIME-OF-FLIGHT SYSTEM FOR DETECTION OF LOW-ENERGY HEAVY EVAPORATION RESIDUES AT THE ELECTROSTATIC SEPARATOR VASSILISSA

A large-area thin timing detector for slow heavy nuclei was developed. The apparatus is based on the transport of secondary electrons by cro ssed electric and magnetic fields with subsequent amplification by mic ro-channel plate multipliers. To increase the registration efficiency secondary electrons are collected from the both sides of the emitter f oil, An intrinsic time resolution of (380+/-30) ps and registration ef ficiency of (95+/-5)% were obtained for the single TOF detector using a Ra-226 alpha-source. A time resolution of (400+/-30) ps and registra tion efficiency close to 100% were measured for heavy ions for the sin gle TOF detector, A time-of-flight system consisting of two such detec tors is extensively used in the experiments with heavy nuclei at the k inematic separator VASSILISSA [1,2].