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Ruth, R.D.

Paper Title Page
TPAE030 Distributed Bragg Coupler for Optical All-Dielectric Electron Accelerator 2125
 
  • Z. Zhang, R.D. Ruth, S.G. Tantawi
    SLAC, Menlo Park, California
 
  Funding: Department of Energy.

A Bragg waveguide consisting of multiple dielectric layers with alternating index of refraction becomes an excellent option to form electron accelerating structure powered by high power laser sources. It provides confinement of a synchronous speed-of-light mode with extremely low loss. However, laser field can not be coupled into the structure collinearly with the electron beam. There are three requirements in designing input coupler for a Bragg electron accelerator: side-coupling, selective mode excitation, and high coupling efficiency. We present a side coupling scheme using a Bragg-grating-assisted input coupler to inject the laser into the waveguide. Side coupling is achieved by a second order Bragg grating with a period on the order of an optical wavelength. The phase matching condition results in resonance coupling thus providing selective mode excitation capability. The coupling efficiency is limited by profile mismatch between the outgoing beam and the incoming beam, which has normally, a Gaussian profile. We demonstrate a non-uniform distributed grating structure generating an outgoing beam with a Gaussian profile, therefore, increasing the coupling efficiency.

 
FOAB007 The Compact Light Source: A Miniature Synchrotron Light Source
 
  • R.D. Ruth
    Lyncean Technologies, Inc., Palo Alto, California
 
  Funding: Supported by the National Institute of General Medical Sciences, the National Insitutes of Health, R44 GM665011.

During the past 30 years, synchrotron light sources have become the x-ray probe of choice for physicists, chemists, biologists and research physicians. With their high-quality, intense x-ray beams, these national research facilities have spawned a broad array of applications. Past research at Stanford Linear Accelerator Center has led to a new x-ray source concept that can substantially reduce the size of the required synchrotron.* This research has spawned a new corporation, Lyncean Technologies, Inc. which is now developing the Compact Light Source (CLS). The CLS is a tunable, homelab x-ray source with up to three beamlines that can be used like the x-ray beamlines at the synchrotrons–but it is about 200 times smaller than a synchrotron light source. The compact size is achieved using a laser undulator and a miniature electron-beam storage ring. The photon flux on a sample will be comparable to the flux of highly productive synchrotron beamlines. At Lyncean Technologies, Inc. we have constructed a prototype of this source with funding from the NIGMS Protein Structure Initiative. I will report on commissioning progress and long-term outlook for the Compact Light Source.

*Z.Huang and R.D. Ruth, "Laser-Electron Storage Ring," Phys. Rev. Lett., 80:976-979, 1998.