Author: Lee, H.
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MOPIK023 Cornell Laboratory for High Intensity, Ultra-Bright and Polarized Electron Beams 551
 
  • L. Cultrera, A.C. Bartnik, I.V. Bazarov, C.M. Gulliford, P. Gupta, H. Lee, S.A. McBride, T.P. Moore
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Funding: This work has been funded by the National Science Foundation (Grant No. PHY-1416318) and Department of Energy (Grants No. DE-SC0014338, No. DE-SC0011643 and No. DE-SC0016203).
We report on the current activities pursued at Cornell University for the production of electron beams tailored to a wide range of applications. We have developed the expertise to grow many different type of high quantum efficiency photocathode belonging to the alkali antimonide family. Those materials are ideal candidates to produce high intensity beam with average currents in the mA range. When operated near threshold at cryogenic temperature in transmission mode they can also generate the electron beams needed to perform ultrafast electron diffraction of bio molecules. We have recently expanded our facility with a Mott polarimeter to include the capability to measure polarization of the electron beam. The photocathode lab is being complemented by a dedicated photo-gun laboratory to test the photocathode properties in a real environment and to perform measurement of the beam properties under new and yet unexplored operating conditions. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK023  
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TUPAB127 A Cryogenically Cooled High Voltage DC Photogun 1618
 
  • H. Lee, I.V. Bazarov, L. Cultrera
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  A DC high voltage photogun with cryogenically cooling of the electrode has been newly built at Cornell University. This gun is designed to provide a DC high voltage and a photocathode in this gun can be cooled down to a cryogenic temperature. A photocathode puck design from INFN/DESY/LBNL is used, so we will be able to run a photocathode from other institutions as well. This paper describes the mechanical, thermal, and high voltage design of this gun. We also present data of high voltage conditioning and the thermal profile along the electrode structure.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB127  
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TUPAB128 Single Photoemitter Tips in a DC Gun: Limiting Aberration-induced Emittance 1622
 
  • I.V. Bazarov, L. Cultrera, C.M. Gulliford, H. Lee
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • H.K. Fung
    Cornell University, Ithaca, New York, USA
  • J.M. Maxson
    UCLA, Los Angeles, California, USA
  
  Ultrafast electron diffraction (UED) offers unique advantages over x-ray diffraction, like stronger scattering cross-section, versatility in sample types and ability to offer smaller apparatus foot print. There is a growing need to increase brightness of electron beams especially for single-shot UED applications. We explore the utilization of field enhancement from a micron-scale single tip inside a DC gun to obtain brighter sub-pC electron beams using a nominal cathode electric field of several MV/m. The additional field enhancement can place moderate voltage sources on par with the highest gradient devices and allow improved performance presently not possible in the existing photoemission guns.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB128  
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