Accelerator Physics and Engineering Seminars

Below is a list of seminars related to the Accelerator Science and Engineering Traineeship (ASET) program.

The ASET program at MSU leverages unique campus-based equipment, systems, and experts at FRIB and NSCL, extensive ASET faculty and research support in several MSU academic programs, and resources at U.S. Department of Energy national laboratories. 

2022

28 January 2022
DC Photoemission Guns and a Quest for Higher Operating Voltage
Carlos Hernandez-Garcia, Thomas Jefferson National Accelerator Facility

Talk abstract: High voltage DC photoemission electron guns have demonstrated high performance for a variety of meaningful accelerator applications, including:

  • Ultra-high vacuum required for obtaining long-photocathode lifetime from high polarization GaAs photocathodes for nuclear physics
  • Generating tens of mA for electron coolers, energy recovery linacs, and free-electron lasers
  • Bright electron beams for electron microscopy and for ultra-fast electron diffraction

The photocathode accelerating field must be sufficiently high (often > 10 MV/m) to compensate for high bunch charge and improve injector transmission, imposing challenging requirements to reliably apply high voltage to the electrodes and HV feedthroughs without breakdown. Further, the electrodes must be free of field emission to preserve the vacuum conditions necessary for long photocathode lifetime. At Jefferson Lab, we have developed compact DC high voltage photoguns based on an inverted-geometry ceramic insulator concept. Our design is based on achieving exceptional vacuum, being free of field emission and operating with reliable approaches to applying high voltage to the photogun. I will provide an overview of DC photogun designs in operational accelerators, practical considerations to reliably apply high voltage, and summarize both successes and failures learned over the two past decades in building these photoguns.

14 January 2022
EDM Measurement in Small Rings
Vasiliy Morozov, Oak Ridge National Laboratory

Talk abstract: V.S. Morozov1, R. Suleiman2, and Ya.S. Derbenev2 present a new design of highly-specialized small storage rings for low-energy polarized electron beams. The new design is based on the transparent spin methodology that cancels the spin precession due to the magnetic dipole moment at any energy while allowing for spin precession induced by the fundamental physics of interest to accumulate. The buildup of the vertical component of beam polarization can be measured using standard Mott polarimetry that is optimal at low electron energy. These rings can be used to measure the permanent electric dipole moment of the electron, relevant to CP violation and matter-antimatter asymmetry in the universe, and to search for dark energy and ultra-light dark matter.

1Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
2Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA

Past seminars are found on the archive page at the links below: