SLAC, Menlo Park, California
IHEP Beijing, Beijing
LAL, Orsay
IN2P3-LAPP, Annecy-le-Vieux
ICEPP, Tokyo
University of Tokyo, Tokyo
KEK, Ibaraki
CERN, Geneva
The primary aim of the ATF2 research accelerator is to test a scaled version of the final focus optics planned for use in next-generation linear lepton colliders. ATF2 consists of a 1.3 GeV linac, damping ring providing low-emittance electron beams (<12pm in the vertical plane), extraction line and final focus optics. The design details of the final focus optics and implementation at ATF2 are presented elsewhere* . The ATF2 accelerator is currently being commissioned, with a staged approach to achieving the design IP spot size. It is expected that as we implement more demanding optics and reduce the vertical beta function at the IP, the tuning becomes more difficult and takes longer. We present here a description of the implementation of the overall tuning algorithm and describe operational experiences and performances
* Beam-Based Alignment, Tuning and Beam Dynamics Studies for the ATF2 Extraction Line and Final Focus System. Glen R. White , S. Molloy, M. Woodley, (SLAC). EPAC08-MOPP039, SLAC-PUB-13303.
KEK, Ibaraki
The beam extraction experiment using the strip-line kicker has been carried out at KEK-ATF. The specification of the International linear collider (ILC) is that the long bunch train (1320 - 5120 bunches), which has the bunch spacing of 189 - 480ns, is compressed to 3 or 6ns bunch spacing into the DR, and again decompressed from the DR. The kicker manipulates the changes of the bunch spacing. The kicker requires a fast rise/fall time (3 or 6ns) and a high repetition rate (3 or 6MHz). A multiple strip-line kicker system is the most promising candidate to realize the specification for the ILC*. The beam extraction experiment at KEK-ATF** using proto-type of the strip-line kicker was done by following parameters, up to 30 bunches of the multi-bunch in the DR, which has 5.6ns bunch spacing, are extracted bunch-by-bunch with 308ns interval to the extraction line. The stored multi-bunch was extracted successfully. The detail of the experiment and the result are reported.
* T. Naito et. al., Proc. of PAC07, pp2772-2274.
** T. Naito et. al., Proc. of EPAC08, pp601-603.
LAL, Orsay
IN2P3 IPNL, Villeurbanne
CERN, Geneva
BINP SB RAS, Novosibirsk
IHEP Beijing, Beijing
The CLIC study considers the hybrid source using channeling as the baseline for unpolarised positron production. The hybrid source uses a few GeV electron beam impinging on a crystal tungsten target. With the tungsten crystal oriented on its < 111 > axis it results an intense, relatively low energy photon beam due mainly to channeling radiation. Those photons are then impinging on an amorphous tungsten target producing positrons by e+e- pair creation. The downstream capture section is based on an adiabatic matching device and a 2 GHz pre-injector linac. The resulting studies are presented here.