Primary reaction will be fast neutron fission of the Cm-245 isotope. If a secondary is needed, boosting by putting a tiny tritium capsule in the center could increase the energy yield both by fusion and by increasing fission--but the fusion part would have little or nothing to do with D-He fusion. Infact, I would imagine the a tiny bit of LiD in the center could boost quite nicely. Although the problem there is that the pulses may infact become too powerful--especially if they start popping off at 100+ ton yields.