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Title: Dynamically polarized target for the g p 2 and G p E experiments at Jefferson Lab

We describe a dynamically polarized target that has been utilized for two electron scattering experiments in Hall A at Jefferson Lab. The primary components of the target are a new, high cooling power 4 He evaporation refrigerator, and a re-purposed, superconducting split-coil magnet. It has been used to polarize protons in irradiated NH 3 at a temperature of 1 K and at fields of 2.5 and 5.0 Tesla. The performance of the target material in the electron beam under these conditions will be discussed. The maximum polarizations of 28% and 95% were obtained at those fields, respectively. To satisfy the requirements of both experiments, the magnet had to be routinely rotated between angles of 0, 6, and 90 degrees with respect to the incident electron beam. This was accomplished using a new rotating vacuum seal which permits rotations to be performed in only a few minutes.
 [1] ;  [2] ;  [2] ;  [1] ;  [1] ;  [3] ;  [3] ;  [1] ;  [3] ;  [1] ;  [3] ;  [3] ;  [2]
  1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  2. Univ. of New Hampshire, Durham, NH (United States)
  3. Univ. of Virginia, Charlottesville, VA (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
JLAB-PHY-13-1712; DOE/OR-23177-2727
Journal ID: ISSN 0168-9002; arXiv:1305.3295
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment
Additional Journal Information:
Journal Volume: 738; Journal Issue: C; Journal ID: ISSN 0168-9002
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
43 PARTICLE ACCELERATORS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; polarized target; superconducting magnet; dynamic nuclear polarization