Physical assumptions for a design of the DET-12 chamber for detection of delayed neutrons

Abstract

Physical assumptions have been outlined to design a new device (DET-12) for measurements of delayed neutron emitted from samples of fissionable materials activated with neutrons at big fusion-plasma devices. The aim is to support in this way a classic neutron activation method used as one of the hot plasma diagnostics at tokamaks or stellarators. Physical fundamentals of generation of the delayed neutrons are mentioned and a resulting concept of the measuring chamber is presented. A general size and dimensions of particular constituent material layers, and a number and placement of neutron detectors are optimized by means of Monte Carlo modelling of the neutron transport. Recommendations for a technical design of the measuring chamber are formulated.