A small 1.85-GBq 198Au source (maximum beta-particle energy0.961 MeV, average 0.315 MeV) is enclosed in a lead shield justthick enough to absorb all the beta particles. a) Estimate the energy ?uence rate due to bremsstrahlung ata point 50 cm away. b) What is the estimated bremsstrahlung photon ?uence rateat that point for the purpose of assessing the potentialradiation hazard?