A new data for Fusion power density has been obtained for T-3He and T-T fusion reactions, power density is a substantial term in the researches related to the fusion energy generation and ignition calculations of magnetic confined systems. In the current work, thermal nuclear reactivities, power densities of a fusion reactors and the ignition condition inquiry are achieved by using a new and accurate formula of cross section, the maximum values of fusion power density for T-3He and TT reaction are 1.1×107 W/m3 at T=700 KeV and 4.7×106 W/m3 at T=500 KeV respectively, While Zeff suggested to be 1.44 for the two reactions. Bremsstrahlung radiation has also been determined to reaching self- sustaining reactors, Bremsstrahlung values are 4.5×106 W/m3 at T=700 MeV and 3.8×106 W/m3 at T=500 MeV for T-3He and TT reaction respectively, ignation values then are 136 KeV for T-T and 155 KeV for T-3He. So small Zeff mean small ignition and large fusion power. Tritium Fusion Reactions have large ignition temperature than deuterium reactions.
