Cross Section Processing Codes and Data Bases (AMPX)

  • W. W. EngleJr.
Part of the Ettore Majorana International Science Series book series (EMISS, volume 3)


The AMPX system, in continuing development at the Oak Ridge National Laboratory, is a collection of computer programs in a modular arrangement.1 Starting with ENDF-formatted nuclear data files or pseudo-problem-independent multigroup cross-section data, the system includes a full range of features needed to produce problem-dependent neutron, gamma-ray production, and gamma-ray interaction cross-section data for use with neutronics transport codes such as ANISN, DOT, MORSE, KENO, CITATION, and VENTURE.

The capabilities of AMPX modules can be loosely categorized into the following areas: (1) basic cross-section processing of ENDF-formatted data into pseudo-problem-independent cross-section libraries, (2) resonance self shielding with the Nordheim integral treatment, the Bondarenko iterative treatment, or a treatment utilizing a one-dimensional integral transport solution, (3) spectral collapsing using either previously-prepared multigroup spectra to flux weight cross sections or one-dimensional discrete ordinates, one-dimensional diffusion, or infinite medium transport theories to calculate system-dependent spectra and flux weight cross sections, (4) format conversion of cross-section libraries, (5) cross-section library service functions such as editing, punching, managing, modifying data, preparing macroscopic data, etc., (6) and miscellaneous cross-section functions such as first-order checking of data libraries, processing of ENDF-formatted elastic scattering, fission, capture, and total cross sections for resonance nuclides into point values, creating ENDF-type point string libraries from point cross-section libraries, etc.

The modularity of the AMPX system is particularly attractive since it allows the user to choose an arbitrary execution sequence from the approximately 40–50 modules available in the system. The modularity also allows selection from different cross-section treatments, permits efficient adjustment to technological change, and provides a means of utilizing features of other state-of-the-art multigroup cross-section processing systems with features of the AMPX system.

The AMPX system is distributed by the Radiation Shielding Information Center (RSIC) in a package identified as PSR-63/AMPX-II. RSIC’s AMPX package includes the following: (1) a tape containing IBM source decks and assembler language decks for the various modules, data libraries, and input and output for sample problems, (2) the AMPX User’s Guide, and (3) other documents which provide “hints” for the novice user of the system.


Elastic Scattering Data Library Radiation Shielding Novice User Treatment Utiliz 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    N. M. Greene, J. L. Lucius, L. M. Petrie, W. E. Ford III, J. E. White, and R. Q. Wright, “AMPX: A Modular Code System for Generating Coupled Multigroup Neutron-Gamma Libraries for ENDF/B,” QRNL/TM-3706 (March, 1976 ).Google Scholar

Copyright information

© Plenum Press, New York 1980

Authors and Affiliations

  • W. W. EngleJr.
    • 1
  1. 1.Oak Ridge National LaboratoryOak RidgeUSA

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