Third generation of lead slowing-down spectrometers: First results and prospects

At the same neutron-source intensity S, lead slowing-down spectrometers (LS DS) for neutrons possess luminosity 10(3)-10(4) times as great as that of t ime-of-flight spectrometers with the same energy resolution <(Delta E)over bar>/(E) over bar (for the former, <(Delta E)over bar>/(E) over bar approxi mate to 35-45% at a mean energy (E) over bar less than 50 keV). In combinat ion with high-current proton accelerators, third-generation LSDSs can opera te at S values exceeding those acceptable for second-generation LSDSs coupl ed to electron accelerators by a factor of 10(2) to 10(3). At the Institute for Nuclear Research (Russian Academy of Science, Moscow), the first third -generation LSDS facility called PITON (about 15 tons of lead) has been ope rating successfully and a large LSDS (more than 100 tons of lead) is now un der construction. The results of the first experiments at the PITON facilit y are presented, and the experimental programs for both facilities is outli ned.