A Universal Source of Polarized Cold and Ultracold Neutrons at the LNPI WWR-M Reactor

Abstract

A universal source of polarized cold and ultracold neutrons is mounted at the LNPI WWR-M reactor. The liquid hydrogen moderator (volume about 1 litre) is placed at the center of the reactor core. The thermal neutron flux at the source is (1.5 – 2) • 10¹⁴ n/cm²S. The heat release in the source material and in the liquid hydrogen is ~2 kW. The heat power is removed by the circulation of liquid hydrogen in the loop with a heat-exchanger which is connected with the helium refrigerator. The neutron guide system consists of the neutron guide for polarized cold neutrons and the neutron guide for ultracold neutrons (Fig. 1).