New Methods for Measuring Neutron Spectra with Energy from 0.4 eV to 10 MeV by Track and Activation Detectors

Additional possibilities in achieving high-accuracy measurements of continuous neutron spectra by track and activation detectors have been found. An analysis of energy characteristics of detectors containing ²³⁵U in boron filters of different thicknesses shows that they can be used successfully for measuring intermediate neutron spectra. Application of detectors with ²³¹Pa and ²³⁶U considerably increases the accuracy of fast-neutron measurements. The problems associated with increasing the accuracy measurements resulted in the necessity of studying a method for minimizing a directed divergence to use it for unfolding the neutron spectra with energy from 0.4 eV to 10 MeV. A suggested variation of the method makes it possible to decrease the influence of experimental errors and composition of the detector set on the spectrum unfolding errors. The neutron spectra were measured at the Vinča, IBR JINR, and IRT-1000 reactors.