Technique for ultrahigh temperature measurement

A method for determining the temperature of a gas medium by using the effect of rethermalization of thermal neutrons is described. During neutron-atom scattering in a hot medium the neutron energy spectrum hardens. This phenomenon is uniquely connected with the medium kinetic temperature. The method is based on the use of a source of thermal neutrons and a detector sensitive to changes in the neutron energy spectrum. Calculations show a relatively high sensitivity of the method for hydrogen temperatures ranging from 2000 to 5000 deg K