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Problem 2) Assume that a radioactive solid-sealed point source X with the following decay scheme is placed at a fixed distance from the face of 3x3 inch Nal(TI) detector. For simplicity, assume that the intrinsic peak efficiency of the detector is 100% for all photon energies involved. X 75% 25% 2.5 MeV 0.7 MeV 67% 12 MeV 67% Y Z (a) Sketch the expected differential pulse height spectrum from the detector, identifying all important features (such as X-axis, Y-axis, peak energies, etc) (b) Calculate the statistical energy resolution for the 0.7 Me V gamma-ray photopeak based on the following information about the Nal(TI) detector and associated PMT: . Nal(TI) light yield = 38000 photons/Me V . Light collection efficiency = 85% Quantum efficiency = 20% Fano Factor = 0.5