A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z    

England, R.J.

Paper Title Page
TPPT040 X-Band Dipole Mode Deflecting Cavity for the UCLA Neptune Beamline 2627
 
  • R.J. England, B. O'Shea, J.B. Rosenzweig, G. Travish
    UCLA, Los Angeles, California
  • D. Alesini
    INFN/LNF, Frascati (Roma)
  
  Funding: This work was funded by the Department of Energy under Grant No. DE-FG03-92ER40693.

We report progress on the design and construction of a nine-cell dipole (TM 110 mode) cavity for use as a temporal diagnostic of the 14 MeV 300 pC electron bunches generated at the UCLA Neptune Laboratory linear accelerator, with an anticipated temporal resolution of 150 fs at a peak input power of 50 kW. The cavity is a center-fed standing-wave pi-mode structure, operating at 9.6 GHz, and incorporating a knife-edge and gasket assembly which minimizes the need for brazing or welding. Results of initial RF tests are discussed and compared with simulation results obtained using the commercial code HFSS.

 
TOPA006 High Energy Gain IFEL at UCLA Neptune Laboratory 500
 
  • P. Musumeci, S. Boucher, C.E. Clayton, A. Doyuran, R.J. England, C. Joshi, C. Pellegrini, J.E. Ralph, J.B. Rosenzweig, C. Sung, S. Tochitsky, G. Travish, R.B. Yoder
    UCLA, Los Angeles, California
  • S.V. Tolmachev, A. Varfolomeev, A. Varfolomeev, T.V. Yarovoi
    RRC Kurchatov Institute, Moscow
  
  We report the observation of energy gain in excess of 20 MeV at the Inverse Free Electron Laser Accelerator experiment at the Neptune Laboratory at UCLA. A 14.5 MeV electron beam is injected in an undulator strongly tapered in period and field amplitude. The IFEL driver is a CO2 10.6 mkm laser with power larger than 400 GW. The Rayleigh range of the laser, ~ 1.8 cm, is much shorter than the undulator length so that the interaction is diffraction dominated. A few per cent of the injected particles are trapped in a stable accelerating bucket. Electrons with energies up to 35 MeV are measured by a magnetic spectrometer. Simulations, in good agreement with the experimental data, show that most of the energy gain occurs in the first half of the undulator at a gradient of 70 MeV/m and that the structure in the measured energy spectrum arises because of higher harmonic IFEL interaction in the second half of the undulator.  
RPAP033 Investigation of X-Ray Harmonics of the Polarized Inverse Compton Scattering Experiment at UCLA 2303
 
  • A. Doyuran, R.J. England, C. Joshi, J. Lim, J.B. Rosenzweig, S. Tochitsky, G. Travish, O. Williams
    UCLA, Los Angeles, California
  
  Funding: U.S. Dept. of Energy grant DE-FG03-92ER40693.

An Inverse Compton Scattering (ICS) experiment, which will investigate nonlinear properties of scattering utilizing a terawatt CO2 laser system with various polarizations, is ongoing at the UCLA Neptune Laboratory. When the normalized amplitude of the incident laser’s vector potential a0 is larger than unity the scattering occurs in the nonlinear region; therefore, higher harmonics are also produced. ICS can be used, e.g., for a polarized positron source by striking a thin target (such as tungsten) with the polarized X-rays. As such, it is critical to demonstrate the production of polarized scattered photons and to investigate the ICS process as it enters the nonlinear regime. We present the description of the experimental set up and equipment utilized, including diagnostics for electron and photon beam detection. We present the current status of the experiment.