1. NAME AND TITLE
WINDOWS: A Program for the Analysis of Spectral Data Foil Activation Measurements.
INTRIGUE-IIC: Logarithmic and Semilogarithmic Calcomp Plot Routines.
CONVERT: An IBM-to-CDC Program Conversion Code.
WINDOWS is a simplified and slightly faster version of CCC-233/CRYSTAL BALL. Its name
refers to its ability to model integral responses to a neutron flux. These responses may be thought of
as views of the neutron spectrum through a "window" open between the bounds of integration and
colored by the underlying response function.
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
3. CODING LANGUAGE AND COMPUTER
Fortran IV, Assembler Language; IBM 360/370.
4. NATURE OF PROBLEM SOLVED
WINDOWS is capable of unfolding neutron differential spectra, estimating windows and detector
contributions, laying upper and lower bounds for integral response, and obtaining group fluxes from
neutron transport calculations.
5. METHOD OF SOLUTION
Unfolding the neutron spectrum amounts to inverting the set of integral equations (*). Since this
problem in general has no unique solution, WINDOWS seeks the spectrum phi whose shape is closest
to that of a trial spectrum psi, subject to the condition that (*) be satisfied within some preassigned
tolerance. This minimization is achieved by manipulating the normal equations so that Gaussian
elimination can be performed without the need for back-substitution.
6. RESTRICTIONS OR LIMITATIONS
WINDOWS can handle up to 40 foil measurements including group fluxes construed as ideal
7. TYPICAL RUNNING TIME
Running time is dependent upon the difficulty of the tasks posed to WINDOWS as well as the
number of processing cycles included in the input. When the trial spectrum is in good agreement with
the foil activation measurements, unfolding is quick--in the neighborhood of 1-2 sec CPU time per
processing cycle on the IBM 360/91 computer. If the agreement is poor, several iterations will be
required. The linear programming routines are quite time-consuming and can cause the time per cycle
to increase to 10-15 sec.
8. COMPUTER HARDWARE REQUIREMENTS
WINDOWS is operable on the IBM 360/370 computers. It requires 374 K of core storage on the
IBM 360/91 computer. Two tapes or discs are required. Output is sent to a line printer and to a disc
plotter. The clock is not sampled.
9. COMPUTER SOFTWARE REQUIREMENTS
Fortran IV and Assembler Language compilers are required.
Addendum to WINDOWS Documentation.
F. W. Stallmann, J. F. Eastham, and F. B. K. Kam, "Windows--A Program for the Analysis of
Spectral Data Foil Activation Measurements," ORNL/TM-6656 (December 1978).
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, the cross-section library data, the trial spectrum library
12. DATE OF ABSTRACT
KEYWORDS: ACTIVATION DETECTORS; PLOTTING; UNFOLDING