Application of a hybrid method for efficiency calibration of a NaI detector

Highlights: • A novel hybrid method was extended to include other gamma–source forms. • A developed C code was used to calculate the peak efficiency numerically. • The results were validated by means of the MCNPX. • The hybrid method is a time–efficient for peak efficiency calculations. A previously proposed hybrid analytical–numerical method for efficiency calibration of a NaI detector for a point $\gamma$-source is extended and applied for other shapes of sources. The shapes include line, disk, and cylindrical sources of various dimensions and locations with respect to the right circular cylindrical NaI detector. The results obtained by this method have been evaluated through comparison with Monte Carlo (MC) calculations. A relative maximum difference of 3.5% is found between the two methods.