Diffusion equations for a cascade shower which include an energy cutoff and energy parameters for each particle have not previously been studied. In this paper it is found that an inclusion of both permits collision loss to be represented as a discrete process by modifying the differential radiation cross section.

The previous calculation of the energy spectrum of the high energy deuteron beam from the stripping of He3 (UCRL-2150) was thought to be in error, especially as regards the low energy tail, on the basis of some experiments with the neutron time-of-flight detector, which indicated a considerably narrower spectrum than that calculated in UCRL-2150. Since the value used for the attenuation cross section of deuterons in uranium is considerably lower than that presently considered correct a new calculation was made using this latter cross section. Since the equations used in this new calculation differ somewhat from those used in the previous report a brief derivation is given here.