A Precise Measurement of an Electron Beam Energy for Use in Nuclear Physics
Abstract
An accurate calibration of the MIT-Bates electron beam energy has been achieved. The electron beam was injected into the MIT-Bates South Hall Ring and the spin-precession frequency, Ω_s, was measured. From the spin-precession frequency the equilibrium energy of the ring was determined to be E = 370.3115±0.0021± 0.0004 MeV, where the first error is statistical and the second is systematic. The energy of the beam delivered by the LINAC was determined to be E = 369.954± 0.023±0.300 MeV. This provides a rigorous check on the accuracy of the facility's energy analyzing magnets. The first moment of the energy distribution was also measured. By observing the time constant of the spin diffusion with zero power in the South Hall Ring RF cavity, we obtained a value of σγ/γ = ( 3.7 ± 0.5 ) × 10-4. We provide a lower limit to the polarization lifetime. At a beam energy of 370 MeV no measurable decrease in the polarization was observed up to 2 ms after injection.
- Publication:
-
APS Division of Nuclear Physics Meeting Abstracts
- Pub Date:
- October 1996
- Bibcode:
- 1996APS..DNP..FE04Z