Author: Murokh, A.Y.
Paper Title Page
TUPA39
 Bunch Length Measurements of High Brightness Electron Beams in the Single-shot Mode  
 
  • G. Andonian
    UCLA, Los Angeles, California, USA
  • A.Y. Murokh, M. Ruelas
    RadiaBeam, Santa Monica, USA
  • J.C.T. Thangaraj
    Fermilab, Batavia, USA
  
  The determination of bunch length in the single-shot mode is critical for many advanced accelerator and light source facilities as ultra-short beams become more ubiquitous. These short beams (sub-ps) typically emit coherent radiation via transition radiation (or synchrotron or edge radiation) in the terahertz (THz) frequency range. The Real-Time interferometer (RTI) is a solid-state, spatial interferometer that incorporates terahertz optics and a novel linear, pyroelectric detector array that generates single-shot interferograms that are directly correlated to the beam bunch length. The device has been tested for coherent sources in the IR, and recently demonstrated at the Fermilab A0 test facility [1]. In this paper, we review the physical concepts, recent results, and potential future applications at both the Brookhaven National Laboratory Accelerator Test Facility and the SLAC National Laboratory FACET facility.
[1] J. Thangaraj, G. Andonian, R. Thurman-Keup, et al., Rev. Sci. Instrum. 83, 043302 (2012). 		 
 
TUPA40
 High Resolution Bunch Profile Determination with an X-band Deflecting Cavity  
 
  • G. Andonian
    UCLA, Los Angeles, California, USA
  • R.B. Agustsson, L. Faillace, A.Y. Murokh, M. Ruelas
    RadiaBeam, Santa Monica, USA
  
  The determination of the longitudinal profile of high-brightness beams on the ~fs scale is important for many present-day applications that employ ultra-short beams. A direct method to measure the beam profile in the temporal domain utilizes a transverse cavity operating in the zero-crossing mode. Here we present the development and commissioning results of an x-band deflecting cavity that is currently installed at the Brookhaven National Laboratory Accelerator Test Facility. Initial studies and simulations show that a temporal resolution of <10fs is achievable. In addition, we propose a method to enhance this resolution to the sub-fs scale with the addition of a laser-modulator (a high-power laser and an undulator) to impose an angular modulation on the beam. This modulation, in tandem with the transverse cavity, is resolvable on a distant screen; simulations show that temporal resolutions on the sub-fs scale are achievable.  
 
TUPB59
 Beam Diagnostics of Injector Test Facility for PAL XFEL  
 
  • S.J. Park, H. J. Choi, J.Y. Choi, J.H. Han, J.H. Hong, H.-S. Kang, C. Kim, I.S. Ko
    PAL, Pohang, Kyungbuk, Republic of Korea
  • M.S. Chae
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • A.Y. Murokh
    RadiaBeam, Santa Monica, USA
  
  Funding: Supported by the Ministry of Education, Science and Technology in Korea.
We are constructing an injector test facility (ITF) for the PAL XFEL. The target of the facility is to demonstrate an emittance of < 0.5 mm mrad (projected, normalized rms) at the beam charge of 200 pC with small energy spread and high stablities. By collaborating with the RADIABEAM Technologies*, we have developed beam diagnostics with enough precision and reliability to provide beam information including beam energy, energy spread, charge, profile, position, and bunch length. Resolutions of the beam-size and position measurements will be 17.5 um (rms, for OTR screens) and < 10 um (rms) respectively. A S-band transverse deflecting cavity will be used for measuring the bunch length with resolution down to 10 fs. In this article we report on current status of the PAL-XFEL injector test facility with emphases on its beam diagnostics.
* http://www.radiabeam.com/