PSR-0125 GNASH.

1. NAME OR DESIGNATION OF PROGRAM:  GNASH-FKK.

3. DESCRIPTION OF PROGRAM OR FUNCTION

GNASH provides a   flexible method by which reaction and level cross sections, isomer ratios, and emission spectra (neutron, gamma-ray,  and charged-particle) resulting from particle-and- photon-induced reactions can be calculated. The September 1991 release of GNASH incorporated an additional option for calculating gamma-ray strength functions and transmission coefficients by including the Kopecky-Uhl model. In addition, improvements were made to the output routines, particularly regarding gamma-ray strength function information.
Major improvements in the 1995 GNASH-FKK release include  added capabilities: to read in externally calculated  preequilibrium spectrum from, e.g., Feshbah-Kermin-Koonin  theory, to do multiple preequilibrium calculations, to   calculate appropriate spin distributions for nuclear states formed in preequilibrium reactions, and to do incident-photon  calculations.

In the 1998 release, improvements were made  in the accuracy of the exciton model and other calculations, and provision was made for including energy-dependent renormalization of the reaction cross section and energy-dependent exciton model parameterization (for data evaluation purposes).

4. METHOD OF SOLUTION

GNASH uses Hauser-Feshbach theory to calculate  complicated sequences of reactions and includes a preequilibrium correction for binary tertiary channels. Gamma-ray competition is considered  in detail for every decaying compound nucleus. A multi-humped fission barrier model is included for fission cross-section calculations. Three options for level densities are available.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

In its present configuration, each calculation can handle decay sequences involving up to 38 compound nuclei and each decaying compound nucleus can emit a maximum of 5 types of radiation ( neutrons, gamma rays, protons, alphas, etc.). Angular-momentum effects and conservation of parity are included explicitly. Each residual nucleus in a calculation can  contain up to 78 discrete levels whereas its continuum region can be represented by up to 204 energy bins. The incident-particle types that are permitted are neutrons, protons, deuterons, tritons, 3He and 4He. Angular distributions are not calculated; i.e., isotropy is assumed in the center-of-mass (c.m.) system. Angular distribution effects can be added in postprocessing utility codes making use of, for example, Kalbach-Mann systematics. The above restrictions can be easily adjusted by increasing the array dimensions in the parameter statements in the code.

6. TYPICAL RUNNING TIME

The running times typically range from a few seconds to a few minutes per incident energy depending upon incident particle energy, mass range of the target, number of compound nuclei included, and the energy bin width that is used.

7. UNUSUAL FEATURES: UNUSUAL FEATURES OF THE PROGRAM

8. RELATED AND AUXILIARY PROGRAMS

AUXILIARY CODE:
SEARCH3:   Operates on the output of the GNASH-FKK code to produce
            ENDF/B-formatted cross section records.

DATA LIBRARY:
STRUCTURE.DAT: Nuclear level energies, spins, parities, and
                gamma-ray branching ratios.
TRANS.COEF:    Particle transmission coefficients from spherical
                or deformed optical model calculations.
MASS.DAT:      Table of ground-state masses, spins, and parities.

10. REFERENCES

- J. Kopecky and M. Uhl:
  Test of Gamma-Ray Strength Functions in Nuclear Model Calculations
  Phys. Rev. C41, 1941 (1990)
- P.G. Young, E.D. Arthur, M.B. Chadwick:
  Comprehensive Nuclear Model Calculations: Introduction to the
  Theory and Use of the GNASH Code.
  LA-12343-MS (July 1992)

-  M. Chadwick:
   readme.tr98 (January 1998)
-  P.G. Young, M.B. Chadwick:
   Code Input Description, Version T2/PGYC/93GNASH/GN7SRC (Update 17)
  (May 1996)
-  P.G. Young, E.D. Arthur and M.B. Chadwick
   Comprehensive Nuclear Model Calculations: Theory and Use of the GNASH code
  (to be published)  (1998)
-  M. Chadwick:
   readme.tr98  (January 1998)
-  P.G. Young, M.B. Chadwick:
   Code Input Description, Version T2/PGYC/93GNASH/GN7SRC (Update 17)
  (May 1996)
-  P.G. Young, E.D. Arthur and M.B. Chadwick
   Comprehensive Nuclear Model Calculations: Theory and Use of the GNASH code
  (to be published)  (1998)

11. MACHINE REQUIREMENTS

GNASH was developed originally on  the CDC 6600 and 7600 then on CRAY.

The current release runs on Sun Sparcstations. Using GNASH and ENDF evaluations to 150 MeV, requires more than 100 MB RAM, to include all the necessary decay chains.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED

The codes run on  Cray computers under the UNICOS operating system. The gnash and search3 Fortran sources call routines which are Cray specific, but they can be ported to other Unix systems. Calls to filerep and qstart equate internal and external file names and may be removed. Substitutions need to be supplied for "date" and "second" which retrieve calendar data and time of day. Two "encode" statements in search3 may need to be changed.

At RSICC GNASH-FKK was run on a Sun Sparcstation20 under Solaris 2.6 using f77 Vers. 4.2. Double precision (-r8) is needed.

GNASH-FKK  was run on  a PC  Pentium, 200MHz, 32MB  RAM using a Fortran 77 Lahey system.

15. NAME AND ESTABLISHMENT OF AUTHORS

Contributed by:
                Radiation Safety Information Computational Center
                Oak Ridge National Laboratory
                Oak Ridge, Tennessee, U. S. A.
Developed by:
                Los Alamos National Laboratory,
                Los Alamos, New Mexico, U. S. A.

                Dr Anabella TUDORA
                Bucharest University
                Faculty of Physics
                Bucharest Magurele POB MG-11
                R-76900  ROMANIA

gen/ gnash & gnxs srces & problem-independent input files
fe/ Test case inputs and outputs
nb/ Test case inputs and outputs
pb/ Test case inputs and outputs
u/ Test case inputs and outputs
zr/ Test case inputs and outputs
P125TAR5.LIS List of files
README.CD Readme file
README.RSI Readme file

TAPE13 gr.st. masses, spins, parities
GNASH98.ARJ Archive of GNASH98.EXE
ARJ.EXE Executable
GNASH98.FOR Source file
README.TXT Information file
INFE n + Fe56 test case: output file
OUTFE56 n + Fe56 test case: Output file
FE.T8 n + Fe56 test case: TAPE8 file
FE.T10 n + Fe56 test case: TAPE10 file
FE.T33 n + Fe56 test case: TAPE33 file
FE56.T4 GNXS output files obtained with OUTFE56 (TAPE1): TAPE4 file
FE56.T61 GNXS output files obtained with OUTFE56 (TAPE1): TAPE61 file
FE56.T62 GNXS output files obtained with OUTFE56 (TAPE1): TAPE62 file
FE56.T63 GNXS output files obtained with OUTFE56 (TAPE1): TAPE63 file
FE56.T64 GNXS output files obtained with OUTFE56 (TAPE1): TAPE64 file
INNB n + Nb93 test case: input file
OUTNB93 n + Nb93 test case: output file
NB.T8 n + Nb93 test case: TAPE8 file
NB.T10 n + Nb93 test case: TAPE10 file
NB.T33 n + Nb93 test case: TAPE33 file
TAPE50 n + Nb93 test case: TAPE50 file
NB93.T4 GNXS output file obtained with OUTNB93 (TAPE1): TAPE4 file
NB93.T61 GNXS output file  obtained with OUTNB93 (TAPE1): TAPE61 file
NB93.T62 GNXS output file  obtained with OUTNB93 (TAPE1): TAPE62 file
NB93.T63 GNXS output file  obtained with OUTNB93 (TAPE1): TAPE63 file
NB93.T64 GNXS output file  obtained with OUTNB93 (TAPE1): TAPE64 file
INPB gamma + Pb208 test case: input file
OUTPB08 gamma + Pb208 test case: output
PB.T8 Gamma + Pb208 test case: TAPE8 file
PB.T10 Gamma + Pb208 tst case: TAPE10 file
T33 Gamma + Pb208 test case: TAPE33 file
TAPE53 Gamma + Pb208 test case:TAPE53 file
PB08.T4 GNXS output file obtained with OUTPB08 (TAPE1): TAPE4 file
PB08.T61 GNXS output file obtained with OUTPB08 (TAPE1): TAPE61 file
PB08.T62 GNXS output file obtained with OUTPB08 (TAPE1): TAPE62 file
PB08.T63 GNXS output file obtained with OUTPB08 (TAPE1): TAPE63 file
PB08.T64 GNXS output file obtained with OUTPB08 (TAPE1): TAPE64 file
INPU gamma + U238 test case: input file
OUTU gamma + U238 test case: output file
U.T8 gamma + U238 test case: TAPE8 file
U.T10 gamma + U238 test case: TAPE10 file
U.T33 gamma + U238 test case: TAPE33 file
U38.T4 GNXS output file obtained with OUTU (TAPE1): TAPE4 file
U38.T61 GNXS output file obtained with OUTU (TAPE1): TAPE61 file
U38.T62 GNXS output file obtained with OUTU (TAPE1): TAPE62 file
U38.T63 GNXS output file obtained with OUTU (TAPE1): TAPE63 file
U38.T64 GNXS output file obtained with OUTU (TAPE1): TAPE64 file
INZR p + Zr90 test case: input file
OUTZR p + Zr90 test case: output file
ZR.T8 p + Zr90 test case: TAPE8 file
ZR.T10 p + Zr90 test case: TAPE10 file
T33 p + Zr90 test case: TAPE33 file
ZIR.T4 GNXS output file obtained with OUTZR (TAPE1): TAPE4 file
ZIR.T61 GNXS output file obtained with OUTZR (TAPE1): TAPE61 file
ZIR.T62 GNXS output file obtained with OUTZR (TAPE1): TAPE62 file
ZIR.T63 GNXS output file obtained with OUTZR (TAPE1): TAPE63 file
ZIR.T64 GNXS output file obtained with OUTZR (TAPE1): TAPE64 file
README.TXT Information file
GNXS.FOR Source of GNXS code (Trieste '98)
GNXS.ARJ Archive of GNXS.EXE