1973 Volume 22 Issue 12 Pages 681-689
The geometrical efficiencies of a point and a disc source on the radiation detection by a detector with circular window were calculated by a polynomial expression. Those were calculated in the case of a source off the center line of the detector window, too.
It was found that the geometrical efficiency Gpof a point source at a point P (x, z) off the center line, in the case of z≥5A, can be approximately expressed as:
Gp/Go=1.0-1.54 (x/z) 3+0.89 (x/z) 3
Go=1/2 (1.0-D/z) : geometrical efficiency of a point source on the center line.
The geometrical efficiency Gsof a disc source (radius R) on the center line, in the case of z≥5A, can be approximately expressed as:
Gs/Go=1.0-0.84 (R/z) 2+ (R/z) 3