X-ray true coincidence summing correction in Genie 2000.

An analysis algorithm to correct for the gamma-ray true coincidence summing effects for radionuclides decay by cascading photons was developed and implemented in Canberra's Genie 2000 software in 2001. It has been extended to correct for true coincidence summing effects from low energy gamma-rays, KX-rays from electron capturing and internal conversion, and the 511 keV positron annihilation photons. Validation of these extensions shows significant improvement in Genie 2000's true coincidence summing correction capability and the accuracy of nuclide activity measurement.