FANAC: A Shape-Analysis Program for Resonance Parameter Extraction from Neutron Capture Data for Light and Medium-Weight Nuclei

摘要

A least-squares shape analysis program is described which is used at the Karlsruhe Nuclear Research Center for the extraction of resonance parameters from high-resolution capture data. The FORTRAN program was written for light to medium-weight or near-magic target nuclei whose cross sections are characterized, on one hand, by broad s-wave levels with negligible Doppler broadening but pronounced multi-level interference, and on the other hand, by narrow p-, d- ... wave resonances with negligible multi-level interference but pronounced Doppler broadening. Accordingly, the Reich--Moore multilevel formalism without Doppler broadening is used for s-wave levels, and a single-level description with Doppler broadening for p-, d- ... wave levels. Calculated capture yields are resolution broadened. Multiple-collision events are simulated by Monte Carlo techniques. Up to five different time-of-flight capture data sets can be fitted simultaneously for samples containing up to ten isotopes. Input and output examples are given and a FORTRAN list is appended. 8 figures. (ERA citation 04:045660)