Transmission function of a statistical chopper and its application in spectra processing

Some important characteristics of the correlation spectrometer constructed for investigation of neutron inelastic scattering are considered. The purpose of the investigation is to improve processing of correlation spectra. The ideal and real transmission functions of the neutron chopper have been analyzed with the help of the theory of matrices, and their influence on results of evaluating correlation spectra are discussed. On the IBR-30 reactor the transmission function of chopper with a pseudo-random sequence of 127 elements is measured. The data acquisition and the control of measurements wer performed by TPA-i computer and by a special time-division unit. It is shown that the evaluation of the spectra by means of a series, reverse to the measured one, decreases the measurement statistical error