Jefferson Lab > CIO > IR
Privacy and Security Notice

Publications

Publication Information

Title Electrostatic Design and Characterization of a 200 keV Photogun and Wien Spin Rotator
Authors Gabriel Palacios-Serrano
JLAB number JLAB-ACC-21-3467
LANL number (None)
Other number DOE/OR/23177-5278
Document Type(s) (Thesis) 
Category: Electrical Engineering
Associated with EIC: No
Supported by Jefferson Lab LDRD Funding: No
Funding Source: Nuclear Physics (NP)
  Thesis
A PHD thesis
Advisor(s) :
   Carlos Hernandez-Garcia (JLAB)
   Matthew Poelker (JLAB)
Publication Abstract: High-energy nuclear physics experiments at the Jefferson Lab Continuous Electron Beam Accelerator Facility (CEBAF) require high spin-polarization electron beams produced from strained super-lattice GaAs photocathodes activated to negative electron affinity in a high voltage photogun operating at 130 kV dc. A pair of Wien filter spin rotators in the injector provides precise control of the electron beam polarization at the end station target. An upgrade of the CEBAF injector to better support the upcoming Moller experiment requires increasing the electron beam energy to 200 keV, resulting in better transmission through injector apertures and improved photocathode lifetime. In addition, the energy increase is expected to reduce unwanted helicity correlated intensity and position systematics. These requirements led to the design of a shielding electrode described in this work, which minimizes the electric field at the triple-point junction and linearizes the potential along the insulator, thus reducing the risk of field emission induced insulator arcing. The Wien spin rotator design was modified for increasing the electric field from 1.6 to 2.7 MV/m and the magnetic field from 9.1 to 13 mT. The upgrades required detailed modeling in Solidworks, electrostatic simulations using CST, beam dynamics using GPT, device implementation, and in situ high voltage characterization of the world?s first 200 keV polarized photoelectron gun and compatible Wien filter spin rotator.
Experiment Numbers:
Group: Ctr for Injectors&Sources
Document: pdf
DOI: http://doi.org/10.25777/mf9f-r453
Accepted Manuscript:
Supporting Documents:
Supporting Datasets: