NEA-1688 SACALC3.

1. NAME OR DESIGNATION OF PROGRAM:  SACALC3

3. DESCRIPTION OF PROGRAM OR FUNCTION

SACALC3v1.4 calculates the average solid angle subtended by a right cylinder detector, a cuboid detector, a plane disc window detector, a plane rectangular window detector, or a spherical detector to a circular or rectangular, plane, thick or point source at any position and orientation to the detector. The program also calculates the number of hits on the detector sides and the average path length through the detector volume (assuming no scattering or absorption). The current performance of personal computers makes it realistic achieve accuracies of solid angle estimates typically better than 0.03 %.

The program also calculates the number of hits on the detector walls and the average path length through the detector volume (assuming no scattering or absorption).

The input data can be done on screen, or for batch processing, multiple cases can be entered as a text file.

4. METHODS

The program uses a Monte Carlo method to calculate the average solid angle for source-detector geometries that are difficult to analyse by analytical methods. The values of solid angle are calculated to accuracies of typically better than 0.03%. The calculated values from the Monte Carlo method agree closely with those produced by polygon approximation and numerical integration by Gardner and Verghese, and others.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The sources are assumed to be uniformly distributed. To avoid rounding errors, differences less than 1e-12 are assumed to be zero.

6. TYPICAL RUNNING TIME

It depends on the number of random events selected by the user.

7. UNUSUAL FEATURES

The program models non-coaxial and non-parallel geometries, and combinations of source and detector shapes.

10. REFERENCES

- R. Whitcher:
A Monte Carlo Method to Calculate the Average Solid Angle Subtended by a Right Cylinder to a Source that is Circular or Rectangular, Plane or Thick, at any Position and Orientation (Radiation Protection Dosimetry 2006 118(4):459-474)

- R. Whitcher:
SACALC3 v1.4 How to Use (March 2012)

11. HARDWARE REQUIREMENTS

The program runs on any Pentium (or compatible) processor PC, operating Microsoft Windows OS XP, Vista or 7. A screen resolution of 800x600 or higher is preferable, but not essential.

13. SOFTWARE REQUIREMENTS

The program was compiled with Turbo Delphi 2006. On an Intel Core i7 Q740 1.73 GHz with 4 Gbytes RAM under OS Windows 7.

15. NAME AND ESTABLISHMENT OF AUTHORS:
Ralph WHITCHER
Crawley
United Kingdom

SACALC3v14.EXE Executable to run the SACALC3 code
SACALC3 Documentation in PDF Format
SACALC3v14_readfile_example.txt Example of a text file for batch processing