1. NAME AND TITLE

RADAK: Flux Spectra Unfolding Code System--Neutron or Gamma-Ray Detectors.

AUXILIARY ROUTINES

PRC: Calculator of response functions for spherical gas-filled proton-recoil neutron spectrometers.

NE213: Analyzes pulse height spectra from small NE213 organic liquid scintillation spectrometers.

2. CONTRIBUTOR

United Kingdom Atomic Energy Authority, Winfrith, Dorchester, Dorset, England, through the NEA-CPL Computer Program Library, Ispra (Varese), Italy.

3. CODING LANGUAGE AND COMPUTER

Fortran IV, Assembler Language; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

RADAK calculates flux spectra from the output of multi-channel and single-channel neutron or gamma-ray detectors. It solves the sets of simultaneous linear equations which arise when attempting to determine particle flux spectra from experimental measurements. Associated with RADAK are the programs PRC and NE213 which, respectively, provide the responses of gas-filled proportional counters and organic liquid scintillators.

5. METHOD OF SOLUTION

The output from several detectors may be analyzed simultaneously to produce a single-valued flux solution, and allowance may be made for the uncertainties in the detector response functions. The errors, including correlations, of the flux solution are estimated.

RADAK cycles through flux, partition and matrix adjustments. The fixed flux normalization and/or partition normalizations are printed every 5 cycles so that the investigator can check for convergence. Then RADAK prints, for each case, the solution, the residuals on the rhs, and, if smoothing is operative, the weighted scaled first differences.

PRC calculates the recoil proton distribution in a spherical counter due to monoenergetic neutrons. NE213 calculates a flux spectrum by differentiation of the pulse height spectrum after correcting for the non-linearity of the light function.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for RADAK.

8. COMPUTER HARDWARE REQUIREMENTS

RADAK is operable on the IBM 360/370 computers.

9. COMPUTER SOFTWARE REQUIREMENTS

Fortran IV and Assembler Language compilers are required.

10. REFERENCE

M. J. Grimstone, "The RADAK Users' Manual," AEEW-M 1455 (December 1976).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the library routines, source code and sample problem input and output.

12. DATE OF ABSTRACT

March 1984.