Completed Projects

A major experimental capability at Bates, especially during the last years of its operation as a National User Facility for Nuclear Physics, was the Bates Large Acceptance Spectrometer Toroid (BLAST).  BLAST was designed to use the storage ring capability of the South Hall Ring along with internal gas targets, including polarized targets.  The scientific program…

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Historically, electron scattering from nucleons and nuclei was used to measure the size and the electric and magnetic properties of the nucleons and nuclei.  It was always assumed that the scattering was mediated by the exchange of a single photon.  Then, in 2000, measurements at JLab showed a significant discrepancy in the ratio of the…

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Another major and pioneering experimental effort at Bates involved the Out-Of-Plane Spectrometer (OOPS).  OOPS was a special version of coincidence measurements with magnetic spectrometers.  Prior to OOPS coincidence events from electron scattering were carried out with both spectrometers supported in the horizontal plane.  This was the case because the problem of detecting one of the…

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An international collaboration of scientists working at Jefferson Lab has completed a new precision measurement of parity-violating electron scattering on the proton at very low Q2 and forward angles to challenge predictions of the Standard Model and search for new physics. A unique opportunity existed to carry out the first precision measurement of the proton’s…

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Measurement of the Singlet Anomalous Magnetic Moment of the Proton using Parity Violating Elastic Electron Scattering The SAMPLE experiment was designed to measure the contribution of strange quarks to the magnetic moment of the proton.  The experiment was proposed in 1989, and ran in the Bates North Experimental Hall from 1998 to 2001.  The collaboration…

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