1. NAME AND TITLE
CRESO: Resonance Data-handling Code System.
ZRDATA: Cross Sections for Zirconium-91 FROM CNEN/CEA Evaluations.
Comitato Nazionale Energia Nucleare, Bologna, Italy, through the OECD NEA Data Bank, Gif-sur-Yvette, France.
3. CODING LANGUAGE AND COMPUTER
Fortran IV and Assembler Language; IBM 370/160 and IBM 3081.
4. NATURE OF PROBLEM SOLVED
CRESO calculates energy-dependent pointwise neutron cross sections from resonance parameters
read either from cards or from an ENDF/B tape. Both versions IV and V are accepted. It properly
handles the following formalisms: single and multilevel Breit-Wigner, Reich-Moore, Adler-Adler
unresolved resonances with all energy-independent and all energy-dependent parameters and with
energy-dependent fission widths.
5. METHOD OF SOLUTION
In the resolved resonance region, CRESO calculates the cross section at a set of internally
generated energy grid points. The grid is obtained by successively subdividing the intervals between
resonances until the cross section estimated from an interpolation formula is sufficiently close to that
calculated from resonance parameters. The maximum number of sub-intervals between each
resonance is defined by the user. In the unresolved resonance region, cross sections are calculated at
a series of logarithmically spaced energies. The entire energy grid covers the range defined by
ENDF/B rules; however, it may be extended by inputting additional energy points.
6. RESTRICTIONS OR LIMITATIONS
The maximum number of energy points for any reaction is 5000. If this limit is reached, the
calculation proceeds by clearing the buffers and renumbering the points, but it is then no longer
possible to plot all the data or generate an output file in ENDF/B format. Doppler broadening is not
reliable in this event.
7. TYPICAL RUNNING TIME
A sample problem calculating the elastic scattering, capture and total cross section of zirconium-91
in the energy range 10 MeV to 10 keV requires 6 seconds CPU time on an IBM 370/168.
8. COMPUTER HARDWARE REQUIREMENTS
CRESO requires 240 K bytes on an IBM 370/168 computer. The program requires two scratch
devices and two additional decimal units for input and output of cross section data. CRESO was
developed on an IBM 370/168 computer and has been tested on an IBM 3081 computer.
9. COMPUTER SOFTWARE REQUIREMENTS
A Fortran IV compiler is required.
CRESO includes plotting routines designed for a CALCOMP unit but communicates with graphic
software through an interface which can be addressed to any device.
G. C. Panini, "CRESO - A Computer Code for Resonance Data Handling," CNEN-RT/FI(81)30
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one (1.2MB) DOS diskette which contains the source
code and sample problem input and output.
12. DATE OF ABSTRACT
February 1983; updated March 1984.
KEYWORDS: CYLINDRICAL GEOMETRY; GAMMA-RAY; MULTIGROUP; NEUTRON