Photon dose equivalent rate from a cylindrical source using a point kernel technique.
The photon dose equivalent rate as a function of distance from a cylindrical source was calculated using a point kernel technique in the energy range 0.3-5 MeV. Buildup factors for a single medium were those given by the geometric progression formula. The buildup factor for the whole geometry was considered as that from a multilayer shield represented by the Broder formula with two corrections applied to it: the first for finite shield and the second for the contribution of the last layer as given by Kitazume. The accuracy of this algorithm was tested by performing a MCNP (General Purpose Monte Carlo Code for Neutral Particle Transport) calculation for the same source and comparing the two sets of results. The conclusion is that the point kernel technique, with the corrections mentioned above included, gives results that agree with those obtained by using MCNP in most cases to within 10%. Therefore, the method presented here is adequate for performing a dose equivalent rate computation as the effort for using it is much smaller than that needed using the MCNP code.