Abstract

For unfolding neutron spectra at physical accelerator facilities in a very wide energy range, Bonner multi-sphere spectrometers are effectively used. Such spectrometers consist of a thermal neutron detector placed in spherical polyethylene moderators of various diameters which are characterized by certain sensitivity functions. The report proposes an approach to optimizing the choice of the number and size of spheres for conducting rational measurements and subsequent unfolding of neutron spectra using Tikhonov’s regularization method. Our approach is based on the use of weighting factors in the regularization functional, built on the condition numbers of the Gram matrix of the set of sensitivity functions. The effectiveness of the approach is demonstrated using the spectral unfolding of reference neutron fields of the JINR Phasotron.