(Studies of nuclear reaction at very low energies): Technical progress report

Abstract

We summarize the accomplishments of the first full year's operation of the Colorado School of Mines low energy nuclear physics project utilizing the General Ionex Model 1545 low energy, high current particle accelerator. The projects which we have completed which were explicity included in the original contract proposal include the measurement of the gamma ray branching ratios of the p + /sup 6/Li, p + /sup 7/Li, and p + /sup 11/B reactions as well as the absolute yield of the reaction /sup 9/Be(p,..gamma..)/sup 10/B between proton laboratory energies of about 40 to 180 keV. in the course of these measurements we have demonstrated the associated gamma ray technique for Germanium detector efficiency calibration at gamma ray energies up to 12 MeV using very low energy proton beams. We have, in addition, pursued a fairly comprehensive investigation of an extremely interesting and totally surprising phenomenon in which we see a yield of the d-d fusion reaction during bombardment of deuterated polyethylene by light to medium ion and molecular beams which is greatly enhanced over the yield expected from a straight-forward secondary ion reaction calculation. This enhanced yield is seen to correlate with the beam line pressure, suggesting target heating effects to be the source of the enhancement. In conjunction with a parallel contract with the Applied Plasma Physics Program in the DOE Office of Fusion Energy, we have developed an eight channel fast gamma ray spectrometer utilizing the fluorocarbon liquid scintillator NE226. The system has been operated at total gamma ray count rates up to 2.5 MHz with good energy resolution and with no measured dead-time and acceptable levels of pulse pile-up.