Travel grant to support measurement of the astrophysical 4He(3He,g)7Be rate

Lead Research Organisation: University of York
Department Name: Physics


The energy from our Sun, which is essential to maintain life here on Earth, results from a sequence of nuclear reactions which turn Hydrogen into Helium, releasing nuclear binding energy. Several of these reactions also result in the production of neutrinos, very weakly interacting particles which can escape from the Sun and reach us here on Earth. The measurement of these neutrinos in Earth based detectors has resulted in a paradigm shift, since it has revealed that neutrinos have a mass (previously we thought they were massless). The experimental effort is now directed at accurate measurements of the energy spectrum of the neutrinos, from which important details about the structure of neutrinos can be determined. However, paradoxically it is not the accuracy of the measurements which is the limit, but the uncertainty on the flux of neutrinos generated in the Sun. This uncertainty arises because we cannot model the nuclear reaction sequence properly because of uncertainties in the reaction cross sections. One of the key reactions is the fusion of a 3He and a 4He nucleus to form 7Be and the uncertainty in this reaction rate is the remaining major uncertainty in determining the high energy neutrino flux. The situation has been further confused by measurement reported earlier this year which shows a higher reaction rate than previously believed. Our experiment is designed to resolve this discrepancy and to reduce the experimental uncertainty in the cross section measurement.


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Description An experiment performed to measure a key nuclear reaction that is important for energy generation in the sun and the results published
Exploitation Route The results add to the scientific literature and are available to guide future work by other researchers
Sectors Other

Description Nuclear Physics Travel Grant
Amount £3,000 (GBP)
Organisation Science and Technologies Facilities Council (STFC) 
Sector Public
Country United Kingdom
Description Collaboration with research group at TRIUMF Laboratory in Canada 
Organisation TRIUMF
Country Canada 
Sector Academic/University 
PI Contribution Proposed a new experiment to be run at the ISAC Facility at the TRIUMF Laboratory
Collaborator Contribution Beamtime available for experiment at the TRIUMF Laboratory
Impact Collaboration just started. Have been successful in obtaining experimental beamtime, but the experiment has yet to run and so there are no results yet
Start Year 2010