Author: Atkinson, T.
Paper Title Page
WEPWA004 Multi-turn ERL Based Light Source: Analysis of Injection and Recovery Schemes 2129
  • Y. Petenev, T. Atkinson, A.V. Bondarenko, A.N. Matveenko
    HZB, Berlin, Germany
  The optics simulation group at HZB is designing a multi-turn energy recovery linac -based light source. Using the superconducting Linac technology, the Femto-Science-Factory(FSF) will provide its users with ultra-bright photon beams of angstrom wavelength. The FSF is intended to be a multi-user facility and offer a variety of operation modes. The driver of the facility is a 6GeV multiturn energy recovery linac with a split linac. In this paper we compare different schemes of beam acceleration: a direct injection scheme with acceleration in a 6 GeV linac, a two-stage injection with acceleration in a 6 GeV linac, and a multi-turn (3-turn) scheme with a two-stage injection and two main 1 GeV linacs. The key points were costs and beam break up instability.  
WEPWA047 Longitudinal Stability of Multiturn ERL with Split Accelerating Structure 2226
  • Ya.V. Getmanov, O.A. Shevchenko, N. Vinokurov
    BINP SB RAS, Novosibirsk, Russia
  • T. Atkinson
    HZB, Berlin, Germany
  • N. Vinokurov
    KAERI, Daejon, Republic of Korea
  Some modern projects of the new generation light sources use the conception of multipass energy recovery linac with split (CEBAF-like) accelerating structures. One of the advantages of these light sources is the possibility to obtain a small longitudinal beam size. To help reduce it, the longitudinal dispersion should be non-zero in some arcs of the accelerator. However small deviations in voltages of the accelerating structures can be enhanced by induced fields from circulating bunches due to the dependence of the flight time on the energy spread and the high quality factor of the superconducting radio-frequency cavities. Therefore, instabilities related with interactions of the electron bunches and longitudinal modes of the cavities can develop in the installation. Stability conditions for the interactions with fundamental accelerating mode of the split accelerating system are discussed. Numerical simulations are made for two projects - MARS and FSF.