• Dr. Monalisha Dhibar

When gamma rays’ decay in cascade the energies of the coincidence gamma rays are absorbed into the active volume of the detector which gives rise to a gamma spectrum. As a result of the coincidence a sum peak is generated along with the photo peak in the spectrum. These sum peaks make a path for the absolute activity measurement. Modified sum peak method is the way through which absolute activity measurement can be done. In the present work, using this method, we have carried out the measurements and realistic Monte Carlo simulations of the total count rate under the spectrum and peak count rates under the individual peaks of large volume LaBr3(Ce) detector for double gamma emitter sources like Co-60, Nb-94, Sc-46, Na-24. The activity obtained by measurements and simulations for different source and detector combinations are found to be in good agreement with each other. For the first time the Method was tested for big volume 3.5" x 6" LaBr3(Ce) scintillation.

Large volume scintillation detector, modified sum peak, simulation.

"Absolute activity of gamma sources in large volume LaBr3(Ce) detector: Measurements and Simulations ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.10, Issue 1, page no.g745-g750, January-2023, Available :http://www.jetir.org/papers/JETIR2301691.pdf

"Absolute activity of gamma sources in large volume LaBr3(Ce) detector: Measurements and Simulations ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.10, Issue 1, page no. ppg745-g750, January-2023, Available at : http://www.jetir.org/papers/JETIR2301691.pdf