Fusion Reactor Plasmas with Polarized Nuclei

R. M. Kulsrud, H. P. Furth, E. J. Valeo, M. Goldhaber
1982 AIP Conference Proceedings  
Nuclear fusion rates can be enhanced or suppressed by polarization of the reacting nuclei. In a magnetic fusion reactor, the depolarization time is estimated to be longer than the reaction time. The dependence of nuclear fusion reactions on nuclear spin suggests that polarization of the reacting particles may provide some control of the reaction rates and the angular distribution of the reaction products. The large cross section for the reac tion D(T,n) He at low energy arises primarily from a
more » ... s primarily from a J = 3/2 resonant level of He at 107 keV above the energy of the free D 2 and T nuclei. At low energies, the reaction occurs only in the £ = 0 state, so that the angular momentum must be supplied by the spin of the D and T nuclei. Since D has spin 1 and T spin 1/2, their possible combined spin states are S = 3/2 and 1/2. The reaction is due almost entirely to interacting pairs of D and T nuclei with S = 3/2. The statistical weight of this state is 4 while that of the S = 1/2 state is 2. Thus, for a plasma of unpolarized nuclei, effectively only 2/3 of the interactions contribute to the reaction rate. D oisrmiTiuu or ncs MCU^M: <S uaiMirtn
doi:10.1063/1.2945625 fatcat:wfxfon26uff3plbhwjrobmqxzq