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Shkvarunets, A. G.

Paper Title Page
THOAC04 RMS Emittance Measurements Using Optical Transition Radiation Interferometry at the Jefferson Lab FEL 2645
  • M. A. Holloway, R. B. Fiorito, P. G. O'Shea, A. G. Shkvarunets
    UMD, College Park, Maryland
  • S. V. Benson, W. Brock, J. L. Coleman, D. Douglas, R. Evans, P. Evtushenko, K. Jordan, D. W. Sexton
    Jefferson Lab, Newport News, Virginia
  Funding: Office of Naval Research Joint Technology Office

Optical Transition Radiation Interferometry (OTRI) has proven to be effective tool for measuring rms beam divergence. We present rms emittance measurement results of the 115 MeV energy recovery linac at the Thomas Jefferson National Laboratories Free electron Laser using OTRI. OTRI data from both near field beam images and far field angular distribution images give evidence of two spatial and angular distributions within the beam. Using the unique features of OTRI we segregate the two distributions of the beam and estimate separate rms emittance values for each component.

slides icon Slides  
FRPMS033 OTR Measurements of the 10 keV Electron Beam at the University of Maryland Electron Ring (UMER) 4006
  • R. B. Fiorito, B. L. Beaudoin, S. J. Casey, D. W. Feldman, P. G. O'Shea, B. Quinn, A. G. Shkvarunets
    UMD, College Park, Maryland
  Funding: Research supported by Office of Naval Research, Joint Technology Office, and the Department of Energy

We present strong evidence of the observation of optical transition radiation (OTR) from aluminized silicon targets intercepting the UMER 10 keV, 100 ns pulsed electron beam, using fast (300ps and 1ns rise time) photomultiplier tubes. An intensified gated (3ns-1ms) CCD camera is used to image the beam using OTR and to study its time evolution throughout the beam pulse. A comparison of wave forms and time resolved OTR images is presented along with time integrated images obtained with phosphor screens for different initial conditions, i.e. beam currents and gun bias voltages.

correspondance email: rfiorito@umd.edu

FRPMS034 Optical Diffraction-Dielectric Foil Radiation Interferometry Diagnostic for Low Energy Electron Beams 4012
  • A. G. Shkvarunets, R. B. Fiorito, P. G. O'Shea
    UMD, College Park, Maryland
  • M. E. Conde, W. Gai, J. G. Power
    ANL, Argonne, Illinois
  Funding: ONR and the DOD/Joint Technology Office

We have developed a new optical diffraction radiation (ODR) - dielectric foil radiation interferometer to measure the divergence of the low energy (8 - 14 MeV) ANL - Advanced Wakefield Accelerator electron beam. The interferometer employs an electro-formed micromesh first foil, which overcomes the inherent scattering limitation in the solid first foil of a conventional OTR interferometer, and an optically transparent second foil. The interference of forward directed ODR from the mesh and optical radiation from the dielectric foil is observed in transmission. This geometry allows a small gap between the foils (1 - 2 mm), which is required to observe fringes from two foils at low beam energies. Our measurements indicate that a single Gaussian distribution is sufficient to fit the data.

correspondance email: shkvar@umd.edu