ENDT: A FORTRAN PROGRAM TO PREPARE CROSS-SECTION DATA FOR UNC-SAM-3 FROM ENDF/B TAPES.

With the establishment of the Cross Section Evaluation Center at Brookhaven National Laboratory, more detailed, evaluated cross section information has become available, permitting more accurate analysis of problems of interest. In order to make use of this wealth of information in the UNC-SAM-3 Monte Carlo code, the ENDT program, generating an element data tape for later use in UNC-SAM-3 has been written. The present version of the code addresses itself to its use in generating the data required for shielding calculations and takes into consideration the accuracy of todays measurements. ENDT reads the Evaluated Nuclear Data File and calculates total, total scattering, and inelastic cross sections, and established the tables required to treat the angular distribution of neutrons emerging from elastic scattering collisions and the energy distribution of those emerging from inelastic scattering collisions. The code permits Doppler broadening in the resolved resonance range but in the present version no attempt has been made to extend the treatment to all energies since the effect has little significance in shielding calculations. The report tries to document the treatment of the cross section and distribution data, stating explicitly the assumptions made. The FORTRAN listing of the code contains numerous comment cards which should be helpful to a programmer going through the code, and should facilitate the alteration of the code to suit the needs of a given installation. Author