The primary source of high energy neutrinos from the sun is the beta-decay of 8B. The results of solar neutrino experiments that measure neutrino oscillations such as SuperKamiokande and Sudbury Neutrino Observatory depend on the exact spectral shape of the neutrinos from 8B.
We are currently working on an experiment to measure the beta-delayed alpha spectrum from 8B using the novel technique of implanting 8B in a silicon detector. Previous experiments used 8B implanted externally in thin metallic foils and the uncertainties of the foil and source thicknesses are suspected to be the source of the observed discrepancies.
Our technique involves the production of a 8B beam using the ATLAS accelerator at Argonne National Laboratory. Boron nuclei with the proper energy for implantation are selected and deposited into the silicon detector. This setup eliminates systematic errors associated with alpha energy loss in catcher foils and detector dead layers.
The 8B beta and neutrino spectra is complicated by the broad energy profile of the final state. We are currently designing the next generation experiment which will measure the beta-decay spectrum from 8B.
Contact Us | Jan. 2004