**1. NAME AND TITLE**

SECA: Evaluator of Angular Bounds for a Two-Dimensional Symmetric Gaussian
Quadrature Set.

**2. CONTRIBUTOR**

Gibbs and Hill, Inc., New York, New York.

**3. CODING LANGUAGE AND COMPUTER**

Fortran IV; IBM 360/370.

**4. NATURE OF PROBLEM SOLVED**

SECA calculates the azimuthal boundaries of the areas associated with the discrete directions of
the Gaussian quadrature sets used in discrete ordinate calculations for R-Z and X-Y geometries.

**5. METHOD OF SOLUTION**

The method of computation is based on the numerical integration of the analytical expression for
a differential azimuthal strip on a given polar band.

**6. RESTRICTIONS OR LIMITATIONS**

None noted. SECA is a small analysis routine intended to be run on a Load-and-Go basis.

**7. TYPICAL RUNNING TIME**

Compilation, linkage, and execution of a problem which calculated the azimuthal bounds for S_{4},
S_{6}, S_{8}, S_{12}, and S_{16} quadrature sets ran in about two minutes using an IBM 360 compiler with
Optimization = 2.

**8. COMPUTER HARDWARE REQUIREMENTS**

SECA is operable on the IBM 360/370 computers using standard equipment. Approximately 46 K
of core storage is required. No tape drives are needed.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A Fortran IV compiler is required.

**10. REFERENCE**

Roy A. Castelli and Ed Ochoa, "An Analytical Technique for Evaluating the Angular Bounds for
a Two-Dimensional Symmetric Gaussian Quadrature Set," Informal paper (October 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**

March 1984.

**KEYWORDS**: COUPLING, DISCRETE ORDINATES-MONTE CARLO; GEOMETRY
DATA PROCESSING