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Fliller, R. P.

Paper Title Page
TUP040 Progress on a Cryogenically Cooled RF Gun Polarized Electron Source 339
 
  • R. P. Fliller, H. Edwards
    Fermilab, Batavia, Illinois
  
  RF guns have proven useful in multiple accelerator applications. An RF gun capable of producing polarized electrons is an attractive electron source for the ILC or an electron-ion collider. Producing such a gun has proven elusive. The NEA GaAs photocathode needed for polarized electron production is damaged by the vacuum environment in an RF gun. Electron and ion backbombardment can also damage the cathode. These problems must be mitigated before producing an RF gun polarized electron source. In this paper we report continuing efforts to improve the vacuum environment in a normal conducting RF gun by cooling it with liquid Nitrogen after a high temperature vacuum bakeout. We also report on a design of a cathode preparation chamber to produce bulk GaAs photocathodes for testing in such a gun. Future directions are also discussed.  
TUP057 A Compact, Normal-conducting, Polarized Electron, L-band PWT Photoinjector for the ILC 376
 
  • D. Yu, Y. Luo, A. Smirnov
    DULY Research Inc., Rancho Palos Verdes, California
  • I. V. Bazarov
    Cornell University, Ithaca, New York
  • R. P. Fliller
    Fermilab, Batavia, Illinois
  • P. Piot
    Northern Illinois University, DeKalb, Illinois
  
  The International Linear Collider (ILC) needs a polarized electron beam with a low transverse emittance. High spin-polarization (>85%) is attainable with a GaAs photocathode illuminated by a circularly polarized laser. Low emittance is achievable with an rf photoinjector. DULY Research has been developing an rf photoinjector called the Plane Wave Transformer (PWT) which may be suitable as a polarized electron source for the ILC. A 1+2(1/2) cell, L-band PWT photoinjector with a coaxial rf coupler is proposed for testing the survivability of GaAs cathode. It is planned to produce a high-aspect-ratio beam using a round-to-flat-beam transformation. In addition to its large vacuum conductance, the modified PWT has a perforated stainless steel sieve as a cavity wall, making it easy to pump the structure to better than 10-11 Torr at the photocathode. An L-band PWT gun can achieve a low emittance (0.45 mm-mrad for a 0.8nC round beam) with a low operating peak field (<25MV/m). A low peak field is beneficial for the survivability of the GaAs photocathode because electron backstreaming is greatly mitigated.  
TUP092 Emittance Exchange at FNPL 478
 
  • T. W. Koeth
    Rutgers University, The State University of New Jersey, Piscataway, New Jersey
  • R. Andrews, D. A. Edwards, H. Edwards, R. P. Fliller, M. J. Syphers
    Fermilab, Batavia, Illinois
  • P. Piot
    Northern Illinois University, DeKalb, Illinois
  
  An experiment to attempt the exchange of the transverse emittance with the longitudinal emittance of the Fermilab/NICADD PhotoInjector electron beam is being developed. The emittance exchange occurs by placing a TM110 mode RF cavity in the maximum dispersive region of a magnetic chicane. Properly employed, the cavity's longitudinal shearing Electric field zeros the momentum spread at the cost of generating a non-zero betatron oscillation amplitude. We report on the beam line modeling, beam line design, the RF cavity design, present status as well as the future program.  
THP060 Capture Cavity II at Fermilab 719
 
  • T. W. Koeth
    Rutgers University, The State University of New Jersey, Piscataway, New Jersey
  • J. Branlard, R. H. Carcagno, B. Chase, P. Czarapata, H. Edwards, R. P. Fliller, C. M. Ginsburg, B. M. Hanna, A. Hocker, A. Klebaner, M. J. Kucera, M. McGee, D. F. Orris, P. S. Prieto, J. Reid, J. K. Santucci, W. M. Soyars, C.-Y. Tan
    Fermilab, Batavia, Illinois
  
  Capture Cavity II is a 9-cell high gradient TESLA Superconducting cavity intended to upgrade the existing Fermilab Photoinjector electron beam energy from 15MeV to 40Mev. DESY provided the cavity which performed to 33MV/m. Beam tube component preparation and installation onto the cavity was completed at DESY. The cavity was shipped to FNAL under vacuum. Installation and testing of this cavity has provided an opportunity to demonstrate Fermilab’s SCRF High Power Testing infrastructure. We report on the high power RF tests performed with Capture Cavity II at both 4.5K and 1.8K, Cryogenic System Performance, Piezo Electric based fast tuner, and low level RF control.