LSL-M2, Neutron Spectra Log Adjustment for Dosimetry Applications

1 - Description of program or function: LSL-M2 adjusts calculated neutron spectra to make the fluence values consistent with given neutron dosimetry measurements. The primary output is a set of values for the best estimates of damage parameter values; the solution is based on a least squares fit of all input data. Several input spectra, possibly from different irradiations, can be processed simultaneously. 2 - Method of solution: In an adjustment procedure, consistency is achieved by adjusting the input data in such a manner that a weighted sum of squares of adjustments is minimized. The weights are assigned according to the input uncertainties, i.e., the larger the uncertainty, the smaller the weight. This sum, which is further modified by correlations, represents the negative logarithm of the probability of the outcome of the experiment if the adjusted values are the 'true' data. 3 - Restrictions on the complexity of the problem: The results of the adjustment are valid only if the size of the adjustment does not exceed the input uncertainties. The user should also guard against adjustments that exceed the limitations given by the linearization of the problem. The number of spectra times the number of energy groups may not exceed 400. The number of dosimetry measurements must not exceed 100