1. NAME AND TITLE

FANAL: A Least-Squares Shape Analysis Code System.

2. CONTRIBUTOR

Kernforschungszentorum Karlsruhe, Institut f. Neutronenphysik and Reaktortechnik, Karlsruhe, Federal Republic of Germany, through the OECD NEA Data Bank, Gif-sur-Yvette, France.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 370/3033.

4. NATURE OF PROBLEM SOLVED

Resonance parameters are extracted from neutron transmission data using least-squares shape analysis.

5. METHOD OF SOLUTION

FANAL 2 extracts resonance parameters and total cross sections from neutron transmission data obtained by the time-of-flight technique. It permits the determination of up to 50 parameters characterizing the total cross section by simultaneously fitting calculated transmission curves to experimental values from up to 5 different transmission measurements which may differ, e.g., with respect to sample thickness or flight path.

FANAL 2 was developed for structural materials (Cr, Fe, Ni...). Doppler broadening is applied to level sequences with vanishing potential scattering (p-wave resonances). Resolution broadening is applied to calculated transmission (Gaussian resolution function).

Resonance cross sections are treated as pure s-wave cross sections with a potential-scattering contribution from the p-wave.

6. RESTRICTIONS OR LIMITATIONS

Up to 45 resonances are accepted per nuclide and compound spin. The total number of resonance and potential-scattering parameters must not exceed 200 of which not more than 50 can be adjusted during the fit. The constant resonances can lie within or without the energy range of measured data point.

A plot package must be supplied by the user.

The maximum number of data points is 5120 which belong to 5 different time-of-flight runs. The sample material must be the same for all runs and must not contain more than 5 different nuclides.

7. TYPICAL RUNNING TIME

The CPU time needed for a realistic fitting problem (3 iterations) was 18 min 44 sec on an IBM 370/168 computer.

8. COMPUTER HARDWARE REQUIREMENTS

FANAL is operable on the IBM 370/3033 computers. It requires 252 K to execute on an IBM 370/168 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran H compiler is required. The code will need to be modified in order to use a local plotting package.

10. REFERENCE

R. H. Frohner, "FANAL--A Multi-Level Shape-Analysis Program for Resonance Parameter Determination by Least-Squares Fitting of Several Sets of Neutron Transmission Data Simultaneously," KFK 2129 (August 1976).

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

June 1982.