• L. Zang
  Cockcroft Institute, Warrington, Cheshire
• I.R. Bailey
  Lancaster University, Lancaster
• M. Korostelev, A. Wolski
  The University of Liverpool, Liverpool

CLIC will need of order 10 to the 14 positrons per second to achieve its specified luminosity. For such a challenge, an undulator based scheme has been proposed as one of the options for the positron source. As CLIC may operate over a wide range of energy (from 0.5 TeV to 3 TeV), there is a large margin for us to push the performance of the whole system to be more efficient. We report on the undulator parameters and optimization of components of the source such as conversion target, AMD, solenoid and capture RF for different operational scenarios. In addition to maximizing the positron yield the polarization of the positron beam are also considered.

• I.R. Bailey, J.A. Clarke, D.J. Scott
  Cockcroft Institute, Warrington, Cheshire
• I.R. Bailey
  Lancaster University, Lancaster
• C.G. Brown, J. Gronberg, L.B. Hagler, W.T. Piggott
  LLNL, Livermore, California
• L.J. Jenner
  Imperial College of Science and Technology, Department of Physics, London
• L. Zang
  The University of Liverpool, Liverpool

The efficiency of future positron sources for the next generation of high-energy particle colliders (e.g. ILC, CLIC, LHeC) can be improved if the positron-production target is immersed in the magnetic field of adjacent capture optics. If the target is also rotating due to heat deposition considerations then eddy currents may be induced and lead to additional heating and stresses. In this paper we present data from a rotating target wheel prototype for the baseline ILC positron source. The wheel has been operated at revolution rates up to 1800rpm in fields of the order of 1 Tesla. Comparisons are made between torque data obtained from a transducer on the target drive shaft and the results of finite-element simulations. Rotordynamics issues are presented and future experiments on other aspects of the positron source target station are considered.