• G. Burt, R.G. Carter, A.C. Dexter, B.D.S. Hall
  Cockcroft Institute, Lancaster University, Lancaster
• P. Goudket
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• J.D.A. Smith
  Cockcroft Institute, Warrington, Cheshire

Multipactor can be a limiting factor in the design on many SRF cavities, however this is often a difficult phenomena to numerically model. In order to study the reliability of various codes we have undertaken to study the simulation of multipactor in rectangular waveguides and to compare this to experimental results obtained in previous work. In this paper we present the simulation results using CST-Particle Studio.

• G. Burt
  Cockcroft Institute, Lancaster University, Lancaster

Deflecting mode cavities are required in several accelerators for use as crab cavities in colliders and light sources and as separators. The space requirements for these applications are extremely tight due to two or more beamlines being close together. In addition the dipole mode cavities have lower and same order modes in addition to higher order modes which require damping to very low Q values. A number of designs are proposed for compact and/or strongly damped SRF crab cavities. This paper will discuss various coaxial type crab cavities which allow the design of compact crab cavities operating at frequencies below 500 MHz. In addition a number of novel damping schemes will be shown and evaluation of these designs including multipacting will be discussed.

Slides

Talk

• P. Goudket, C.D. Beard, R.K. Buckley, B.D. Fell, J.-L. Fernandez-Hernando, P.A. McIntosh, S.M. Pattalwar
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• P.K. Ambattu, G. Burt, A.C. Dexter, B.D.S. Hall, M.I. Tahir
  Cockcroft Institute, Lancaster University, Lancaster

A superconducting RF vertical test facility (VTF) has been constructed at Daresbury Laboratory to eneable the commisioning of a ILC Crab Cavity LLRF Control System. Two Single Cell 3.9 GHz dipole mode cavities are tested simulataneously to enable the evaluation of the LLRF control system. Carefull tuning of the cavities for frequency and external Q to enable a low noise oscillator to be utilised. Several tests have been performed throughout the past 12 months, each test enabling a much improved system performance. The system is described, and the latest performance of the system is presented.