Difference between revisions of "GTS meeting 6 05 17"

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'''Title:''' Magnetized Electron Beam for Ion cooling at JLEIC
  
  
'''Abstract'''
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'''Abstract:'''
  
JLEIC requires the ion beams to be cooled using co-propagating electron beams moving at the same average velocity but different temperature. The cooling rate can be improved if the process occurs inside a solenoidal field that forces the electrons to follow small helical trajectories thereby increasing the interaction time with ions and improving the cooling efficiency. The fringe field upstream of the cooling solenoid introduces very large beam rotation. To compensate for this effect the electron beam could be generated in a similar field but producing opposite rotation such that the two rotations cancel each other. The anticipated results (demonstration of high-current magnetized beam at 300kV, comparison of the K2CsSb photocathode lifetime difference between magnetized and non-magnetized beam, measurement of magnetization for a variety of charge, bunch dimensions, solenoid strength etc.) and the current status of the magnetized beam (measured results and technical challenges) will be presented.
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A “cooled” ion beam is required to achieve the desired collision luminosity at the Jefferson Lab electron-ion collider (JLEIC). Cooling is the process whereby unwanted transverse motion of ions within an accelerated bunch is transferred to “cold” electrons propagating in the same direction and at the same speed. The cooling rate can be improved if the process occurs inside a solenoidal field – so-called magnetized cooling - that forces the electrons to follow small helical trajectories thereby increasing the interaction time with protons.  However, the upstream fringe field of the cooling solenoid introduces a very large beam rotation. This effect can be cancelled if the electron beam is generated in a similar field but producing rotation in the opposite direction. This poster describes the production of magnetized electron beams using a new DC high voltage photogun biased at 300kV using K2CsSb photocathodes, and presents the current status of measurements against the backdrop of long term goals associated with a multi-year R&D effort that we hope eliminates one of the most significant technical challenges of the JLEIC design.  
  
  

Revision as of 12:35, 6 June 2017

  • Yan's Abstract and Poster Outline:
  1. Abstract is due by June 9, 2017
  2. Poster outline. Poster presentation: June 19, 17:00-19:00.


Title: Magnetized Electron Beam for Ion cooling at JLEIC


Abstract:


A “cooled” ion beam is required to achieve the desired collision luminosity at the Jefferson Lab electron-ion collider (JLEIC). Cooling is the process whereby unwanted transverse motion of ions within an accelerated bunch is transferred to “cold” electrons propagating in the same direction and at the same speed. The cooling rate can be improved if the process occurs inside a solenoidal field – so-called magnetized cooling - that forces the electrons to follow small helical trajectories thereby increasing the interaction time with protons. However, the upstream fringe field of the cooling solenoid introduces a very large beam rotation. This effect can be cancelled if the electron beam is generated in a similar field but producing rotation in the opposite direction. This poster describes the production of magnetized electron beams using a new DC high voltage photogun biased at 300kV using K2CsSb photocathodes, and presents the current status of measurements against the backdrop of long term goals associated with a multi-year R&D effort that we hope eliminates one of the most significant technical challenges of the JLEIC design.


Poster Contents:

  1. Overall Beamline
  2. Major components: Gun solenoid and two slits
  3. Requirements of the electron beam for the JLEIC cooling
  4. Some results: measurement of beam mechanical angular momentum
  5. Technical challenges





  • Emittance Measurements: [1]