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ILC Beam Delivery System / MDI Issues for LCC-phase (~< 2016). Glen White, SLAC May 14 2014 AWLC14, Fermilab. “ All of this has happened before, and will happen again”. BDS Cost Drivers. “Tunnel length” and major infrastructure changes likely to be small BDS tuning “Value Engineering”
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ILC Beam Delivery System / MDIIssues for LCC-phase (~<2016) Glen White, SLAC May 14 2014 AWLC14, Fermilab
“All of this has happened before, and will happen again”
BDS Cost Drivers • “Tunnel length” and major infrastructure changes likely to be small • BDS tuning “Value Engineering” • Emittance -> luminosity • Understand tradeoffs between design choices and impact on time required to deliver required luminosity • FFS complex, non-linear system. Mechanism of tuning system important.
Critical Issues • Lattice design / optics (Thursday BDS sessions) • All lattices -> “complete” status for TDR baseline(250, 350, 500 GeVcm) • both IR’s, (“no-detector” IR?), EXT, tune-up/abort lines • e+ source (lengths correct w.r.t. timing) : BDS responsibility? • linac->BDS transition • FFS optics properly matched and tuned for all configurations • Optics designs for low energy running • 10 Hz specific items : bypass-lines? • Optimal BETA*? • Balance between horizontal and vertical for given luminosity (-> beam dynamics/ tolerance studies) • Determine largest practical L* configuration
Critical Issues • Beam dynamics (BDS/Linac S2E session Tuesday) • Update dynamic tuning simulations (in S2E context) • Evaluate credible luminosity delivery: folding in all error sources and countermeasures • Provide well-motivated and complete list of tolerances • Magnet field accuracy, Multipoles, apertures, component alignment, mover capabilities, PS requirements • Jitter tolerances • Crossing angle • Smaller? Larger? • Try to quantify risk from beam dynamics perspective • Specify incoming beam dynamics tolerances to accept from linac • Review vacuum requirements • Evaluate impact of having 2 different L* optics • Review of diagnostics/technical systems • BPM resolution requirements? • Where are movers really needed?
Critical Issues • Collimation systems & backgrounds : re-evaluate • LW photon detection • Muon shielding requirements • Demonstration of SC FD prototype (vibration tests) • CF / BDS tunnel layout, equipment distribution, central region integration, MDI issues • load distributions • service tunnel • high-power dump enclosures • Muon shielding • Detector hall layout • Crab cavity integration (cryogenics) • SC Octupolecryogenetics • push-pull logistics
Less Critical Issues & Beyond Baseline • Lattice design / optics • “Traditional” vs. baseline FFS • Evaluate tuning efficiency • tail-folding octupoles • Phase-control of FFS • Adequate number of matching quadrupoles? • Profile measurement at FFS IP-image point • Split QF7 • Additional LW infrastructure / technology • Beam dynamics • Wakefield sources : specify complete list • collimators • beam pipes, transitions, ports, chambers, flanges etc • BPMs • Capability to correct momentum dispersion within BDS • Tweaker quads/skew-quads in chicanes? • Commissioning (see joint BDS/MDI/CFS commissioning session) • Consider ability to diagnose fault conditions • Special IR “no-detector” configuration • Need QD0 installation infrastructure? • AUX FD quad/split QF1? • Additional IP-based BPMs/profile monitor(s)?