My research is presently focussed on two topics in the general areas of nuclear astrophysics and fundamental interactions. In collaboration with Asst. Professor R.B. Vogelaar and Dr. M. Chen of the nuclear physics group and Professor Jay Benziger of Chemical Engineering, I am participating in the development of a large liquid scintillation spectrometer which is designed to detect low energy solar neutrinos. The main design goal of the experiment is to measure the flux of the 0.86 MeV 7Be neutrinos from the sun. The motivation for this measurement is based on the results of present solar neutrino experiments (Gallium, Kamiokande, and Chlorine), all of which detect significantly fewer neutrinos than expected. These results can be explained by a strong suppression of the 7Be neutrinos, possible due to matter induced neutrino oscillations (the MSW effect). A direct measurement of the low energy neutrinos by direct live time counting would be conclusive evidence for this suppression. Since the detection of low energy neutrinos places unprecedented requirements on the purity of the detector, especially for naturally occurring radioactivities such as U and Th, a prototype detector is being constructed to measure U and Th at concentrations of less than 10-16 g/g. At present we are completing the installation of the prototype detector in the Gran Sasso underground laboratory in Italy. Results are expected in the spring of 1995.
In addition to the solar neutrino experiment, I have an interest in studies of fundamental symmetries in nuclear beta decay, particularly to search for violations of time reversal symmetry and evidence for right handed currents in nuclear beta decay. The experiments require spin polarized beta unstable nuclei. We have developed atomic beam methods for polarizing the short lived 19Ne nucleus. With Dr. Albert Young, graduate students Gordon Jones and Stan Anderson are completing experiments with newly developed detector methods on right hand currents and time reversal invariance. Their expected sensitivities will surpass all previous studies and set stringent limits for possible theoretical explanations of the famous CP violation phenomenon. In the future I have an interest to explore optical pumping methods to extend these studies beyond the limits of the atomic beam method.