Workshop Aim and Numbers The aim of the
Workshop Aim and Numbers The aim of the workshop is to review the status of the ILC and CLIC beam dynamics studies. It should foster code development and benchmarking between different codes as well with experimental data. In particular, the maximum use of the test facilities CTF 3 and ATF 2 will be discussed in detail. Further, the work programme for the future will be discussed with the emphasis on integrated studies and the preparation of the TDR for ILC and CDR for CLIC. 3 days 36 registered participants >40 contributions 1 power cut
Imperfections Modelling • Two alignment studies – Oxford: theoretical study of use of markers – CERN: practical and theoretical study of wire-based system • Further improvements envisaged – Potential for synergy in calculations (Thomas) • Ground motion modelling – Some progress in data analysis – Vibrations at ATF 2 – Need to have model including support and stabilisation (Christophe, Juergen, Benoît) • Dynamic stray fields – Measurements • Proposal to have Fermilab experts come over and perform measurements at CERN/DESY (Daniel) – Simulation of impact (Jochem)
Drive Beam and CTF 3 • Progress on frequency multiplication scheme – More studies needed (Bernard, Caterina) • Decelerator well studied – Updates might be required (Erik, once his thesis is finished) • Losses in decelerator can be studied (HTGEN+PLACET) – Losses appear small 1 e-7 but more studies to follow (Helmut, Miriam) • Looking for more collaborations on drive beam
RTML • Significant effort for ILC – Relative complete design – Now come close to target performance for single stage compressor – Better performance for double stage compressor • We have holes in the design – Addressing the bunch compressors is the right choice – Instrumentation, collimation, spin rotation missing – Should copy as much as we can (Frank) • Need performance studies – Try to copy as much as possible (Frank) • We agreed to receive some help for a system of our choice – Need to decide system (Frank) • Need to look at integrated issues like current and phase stability – Including damping ring and injectors (Yannis, Louis, Frank)
Main Linac • Coupler kick had been a concern for ILC – Now essentially solved • Study of short range wakefield formulae – Good agreement with formula that we used – Where we err, we err on the good side • Structure tolerances – Tight but not out of reach (Riccardo) • Hope to progress on the comparative study for the main linac (Daniel) – First pre-corrected machine – Then maybe uncorrected machine and correction
BDS and ATF 2 • Our BDS is quite complete – Improvements welcome – Collimation needs work – Hardware issues, e. g. final quadrupole • Good progress at ATF 2 – Hardware development and experience • Need to improve our tuning algorithm – No effort for ILC visible – ATF 2 is ideal test bed with effort from ILC and CLIC side (Rogelio, Eduardo) • Solenoid simulations – Important limitation on anti. D for CLIC – Collaboration with Saclay (Barbara) • Discussion about low-beta functions – First stable beam then low beta-function (Rogelio, Eduardo) • Post collision line with collaboration of UK – Rob Appleby (Rogelio)
Collimation • Collimation requirements have been re-established – Some follow-up (Barbara) • Collimator alignment needs to be accurate to few micrometres – Alignment procedure to be studied (Jochem? , Eduardo? ) • Beam jitter is amplified – Should be included in all studies (Jochem, Eduardo, . . . ) • Faster wakefield for PLACET collimators – No systematic benchmarking has been done sofar – According to Javier current routines 10 minutes for one bunch (more than the whole rest of the tracking) – New routines from Adina should be faster (Barbara) • Dielectric solution for LHC collimation does not seem to work for CLIC
Dynamic Effects • Stabilisation feedback as orbit correctors – Significant progress, more to come (Juergen) • Intra-pulse interaction point feedback – Important, will need interaction with detectors (? ) – Collaboration on kicker for CLIC drive beam phase feedback (Daniel) • Feedback theory – Could expect some help with adaptive feedback (Juergen) • Integrated studies are important (Jochem+)
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