skip to main content

Title: Using Polarimetry to Determine the CEBAF Beam Energy

As Jefferson Lab begins operations with its upgraded CEBAF a ccelerator, the lab once again needs to experimentally determine the absolute beam energy of the machine. Previously, the CE- BAF beam energy was determined using precision measurement s of the bending magnet integral fields along with beam position information. The result obta ined from this technique was cross- checked with elastic scattering from hydrogen where knowle dge of the scattering angles of the electron and proton allow the beam energy to be determined. Wh ile the field integral method will still work with the upgraded machine, the elastic cross sect ion becomes too small to make preci- sion measurements at angles that are large enough to be easil y accessible; thus a new technique for energy determination has been sought. It will be shown th at by making use of polarimetry, one can use CEBAF’s polarized electrons’ g-2 spin precessio n to determine the absolute beam energy. This can be done in a single hall if the parameters of t he machine, such as the injector energy and linac imbalance, are known or with two halls witho ut any knowledge of the machine parameters
  1. JLAB
Publication Date:
OSTI Identifier:
Report Number(s):
JLAB-PHY-13-1785; DOE/OR/23177-2851
DOE Contract Number:
Resource Type:
Resource Relation:
Journal Name: Proceedings of Science; Journal Volume: PSTP2013; Conference: PSTP 2013 (15th International Workshop on Polarized Sources, Targets, and Polarimetry), 09-13 Sep 2013. Charlottesville, VA, USA
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States