Measurement of the 8B neutrino spectrum

Abstract

The neutrino spectrum from the decay of 8B is a crucial ingredient in interpreting recent data from solar neutrino detectors. The β + decay of 8B proceeds to a broad state in 8Be, and the shape of the neutrino spectrum may be obtained from a measurement of the α spectrum following the β + decay. A new technique has been used at the ATLAS accelerator to measure this spectrum by implanting 8B particles into the mid-plane of a 91 μm thick Si detector. The advantage of this method is that both α particles are detected and systematic effects due to energy loss in catcher foils and dead layers of the detector are eliminated. To calibrate the detector, α's from the decay of 20Na ions produced and implanted with the same technique were used.