Studies of nuclear reaction at very low energies

The deuteron radiative capture reactions on {sup 2}H, {sup 6}Li and {sup 10}B have been measured between center of mass energies of 20 and 140 keV. Of note is the observation that the gamma ray-to-charged particle branching ratio for the DD reaction appears independent of energy down to a center of mass energy of 20 keV, consistent with some and contrary to other theoretical models. We have investigated the ratio of the reactions D(d,p)T and D(d,n){sup 3}He down to c.m. energies of 3 keV and the ratio of the reactions 6Li(d,p){sup 7}Li and {sup 6}LI(d,{alpha}){sup 4}He down to a c.m. energy of 19 keV. The DD reaction ratio is independent of energy while the (d,p) branch of the D-{sup 6}Li evinces a significant enhancement at the lowest measured energies. We have continued our investigation of charged particle production from deuterium-metal systems at a modest level of activity. Noteworthy in this investigation is the observation of 3 MeV protons from deuteron beam loaded Ti and LiD targets subjected to extreme thermal disequilibria. Significant facility improvements were realized during the most recent contract period. Specifically the downstream magnetic analysis system proposed to eliminate beam induced contaminants has been installed and thoroughly tested.more » This improvement should allow the D(a,{gamma}){sup 6}Li reaction to be measured in the coming contract period. A scattering chamber required for the measurement of the {sup 7}Li({sup 3}He,p){sup 9}Be reaction has been designed, fabricated and installed on the accelerator. A CAMAC based charged particle identification system has been assembled also for use in our proposed measurement of the {sup 7}Li({sup 3}He, p){sup 9}Be.« less