A study on the calibration of a time-focused Inelastic Neutron Scattering Spectrometer

The calibration of a time-focused spectrometer for the analysis of inelastically back-scattered neutrons is discussed. By comparison with a reference spectrum, a non linear system of the kinetic equations for neutrons is obtained and the calibration process is outlined. This provides a deeper understanding of the question of expected inaccuracies on the measured spectra. In particular, the effect on the parameters of a possible misassignment of the reference spectrum features is examined in detail. A suitable molecular crystal (2,5 diiodothiophene) is identified as the recommended calibrant. Using different transitions from the spectrum of this calibrant the inaccuracies introduced by misassignment are assessed.