Neutron suppression in polarized dd fusion reaction - art. no. 054614

We report a model-independent partial-wave analysis of polarized nd fusion reactions at low energies. The radial transition amplitudes, designated by the central, spin-orbit, and tensor forces, are determined by fitting angul ar distributions of the tensor and vector analyzing powers A(XZ)(theta), A( ZZ)(theta), A(XX-YY)(theta), and A(Y)(theta), and the unpolarized cross sec tion sigma(0)(theta). The polarized fusion cross section sigma(1,1)(theta) is then predicted from these radial transition amplitudes. We stress that t his is feasible only when these amplitudes are separated according to the t ensor rank of the interaction. This study includes the D-state components o f the deuteron, triton, and He-3, and the partial-wave expansion is done up to the d wave for both the entrance and exit channels. Experimental data a t E-lab = 30, 50, 70, and 90 keV for the d(d,p)t reaction are very well fit ted with this method. It is found that the ratio of polarized to unpolarize d cross sections is about 86% at 30 keV and goes down to 22% at 90 keV. The implication of the suppression of a polarized dd fusion reaction is discus sed in the context of the neutron-lean fusion reactor with polarized D-He-3 fuel. It turns out that the important range of energy for suppressing the d(d,p)t and d(d,n)He-3 reactions at the plasma temperature T = 60 keV is E- d = 80-600 keV. More experimental data are needed in this range to make a d etailed study of the neutron suppression. [S0556-2813(99)04409-X].