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.
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