Author: Tantawi, S.G.
Paper Title Page
MOP047 A 200 μm-period Laser-driven Undulator 131
  • F. Toufexis, T. Tang, S.G. Tantawi
    SLAC, Menlo Park, California, USA
  Funding: This project was funded by U.S. Department of Energy under Contract No. DE-AC02-76SF00515 and the DARPA AXiS program.
To reduce the linac energy required for a given synchrotron radiation wavelength, and hence the size of the device, a smaller undulator period with sufficient field strength is needed. In this work, a microfabricated, laser-driven undulator with 200um undulator period is proposed. A TE wave that co-propagates with the electron beam is excited between two polysilicon thin films, having a gap of 16.5um. The mode that is excited is a deflecting mode and causes the electron beam to wiggle. The device is fabricated on a silicon wafer, using conventional silicon micromachining techniques. A single polysilicon thin film is supported on a silicon chip, which has a slit from the back to allow delivery of the laser beam. Two such chips are bonded together to form a 16.5um gap, within which the electron beam passes through. The final device has dimensions 1cm x 1cm x 1.1mm and has approximately 35 undulator periods. In this paper, the model, design, fabrication, and cold measurements of the device are reported.