Author: Xiao, L.
Paper Title Page
TUPEA087 Experiment on Multipactor Suppression in Dielectric-loaded Accelerating Structures with a Solenoid Field 1319
 
  • C.-J. Jing, S.P. Antipov, A. Kanareykin, P. Schoessow
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • C. Chang, L. Ge, L. Xiao
    SLAC, Menlo Park, California, USA
  • M.E. Conde, W. Gai, R. Konecny, J.G. Power
    ANL, Argonne, USA
  • S.H. Gold
    NRL, Washington, DC, USA
 
  Funding: US DoE SBIR Phase I project under contract #DE-SC0007629
Efforts by numerous institutions have been ongoing over the past decade to develop a Dielectric-Loaded Accelerating (DLA) structure capable of supporting high gradient acceleration when driven by an external rf source. Multipactor is the major issue limiting the gradient that was revealed in earlier experiments. A theoretical model predicts that the strength of solenoid field within an optimal range applied to DLA structures may completely block the multipactor. To demonstrate this approach, two DLA test structures have been built and the first high power test will be conducted in December 2012. The results will be reported.
 
 
WEPFI082 Double-tip Magnetic Field Enhancement 2887
 
  • F.Y. Wang, L. Xiao
    SLAC, Menlo Park, California, USA
 
  The local electric field enhancement factor β in an rf accelerator cavity has been studied experimentally for decades and found to be in the range from few tens up to few hundreds for various rf frequencies and materials. A large field enhancement factor is usually thought to come from sharp tips whose β is roughly the ratio of their height to their tip radius. For a β of few hundred, the corresponding tip height would need to be more than 10 microns, which should be visible in a scanning electron microscope (SEM). However, the estimated β from SEM images of cavity surfaces is around 10. Therefore, the physics of such large β values is still not clear. In this paper, we have studied differentμstructures and found that the magnetic field could be enhanced many times in the presence of two nearby tips with β of 10. The large local magnetic field enhancement could lead to large enhanced pulsed heating and thus could melt surface in a very short time and form a liquid Taylor cone.