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 /sup 235/U in boron filters of different thicknesses shows that they can be used successfully for measuring intermediate neutron spectra. Application of detectors with /sup 231/Pa and /sup 236/U 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 Vinca, IBR JINR, and IRT-1000 reactors.