IHEP Beijing, Beijing
JAI, Egham, Surrey
KEK, Ibaraki
ICEPP, Tokyo
SLAC, Menlo Park, California
University of Tokyo, Tokyo
Funding: NSFC 10525525 and 10775154. CNRS-IN2P3 and ANR.
The ATF2 project is the final focus system prototype for ILC and CLIC linear collider projects, with a purpose to reach a 37nm vertical beam size at the interaction point. We report on techniques developed based on simulation studies to adjust the horizontal and vertical beam waists independently in the presence of errors, at two different IP locations where the beam size can be measured with different accuracies. During initial commissioning, we will start with larger than nominal β-functions at the IP, to reduce the effects from higher-order optical aberrations and thereby simplify the optical corrections needed. The first measurements in such intermediate β-configurations are reported.
JAI, Egham, Surrey
Royal Holloway, University of London, Surrey
OXFORDphysics, Oxford, Oxon
KEK, Ibaraki
Funding: STFC LC-ABD Collaboration, Royal Society, Daiwa Foundation, Commission of European Communities under the 6th Framework Programme Structuring the European Research Area, contract number RIDS-011899
The KEK Accelerator Test Facility (ATF) extraction line laser-wire system has been upgraded, enabling the measurement of micron scale transverse size electron beams. The most recent measurements using the upgraded system are presented, including the major hardware upgrades to the laser transport, the laser beam diagnostics line, and the mechanical control systems.
SLAC, Menlo Park, California
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
JAI, Oxford
KEK, Ibaraki
IHEP Beijing, Beijing
LAL, Orsay
Royal Holloway, University of London, Surrey
IN2P3-LAPP, Annecy-le-Vieux
OXFORDphysics, Oxford, Oxon
ATOMKI, Debrecen
CERN, Geneva
DESY, Hamburg
Fermilab, Batavia
Kyungpook National University, Daegu
PAL, Pohang, Kyungbuk
Kyoto ICR, Uji, Kyoto
ICEPP, Tokyo
University of Tokyo, Tokyo
UCL, London
BNL, Upton, Long Island, New York
Tohoku University, Graduate School of Science, Sendai
UMAN, Manchester
Hiroshima University, Graduate School of Science, Higashi-Hiroshima
Cockcroft Institute, Warrington, Cheshire
ATF2 is a final-focus test beam line that attempts to focus the low-emittance beam from the ATF damping ring to a beam size of about 37 nm, and at the same time to demonstrate nm beam stability, using numerous advanced beam diagnostics and feedback tools. The construction is well advanced and beam commissioning of ATF2 has started in the second half of 2008. ATF2 is constructed and commissioned by ATF international collaborations with strong US, Asian and European participation.
UCL, London
Royal Holloway, University of London, Surrey
Kyungpook National University, Daegu
KEK, Ibaraki
SLAC, Menlo Park, California
Fermilab, Batavia
University of Cambridge, Cambridge
The ATF2 international collaboration is intending to demonstrate nanometre beam sizes required for the future Linear Colliders. An essential part of the beam diagnostics needed to achieve this goal is the high resolution cavity beam position monitors (BPMs). In this paper we report on the S-band system installed in the final focus region of the new ATF2 extraction beamline. It only includes 4 BPMs, but they are mounted on the most critical final focus magnets squeezing the beam down to 35 nm. We discuss both the design and the first operational experience with the system.