Download presentation
Presentation is loading. Please wait.
1
RTML and Main Linac Design (2.6.1 and 2.7.1)
PT SLAC ILC R&D Meeting Global Design Effort
2
2006 BC Emittance Preservation
Kubo-san did studies using steering and dispersion bumps Predicted rather large emittance dilutions Not reproduced when SLAC team did nominally-identical studies SLAC team got much smaller emittance growths, even for simple case of misaligned quads and BPMs What’s up with this? ILC R&D Meeting Global Design Effort
3
2006 BC Emittance Preservation (2)
Found 2 differences in the studies Kubo-san’s study did not include cavity fringe fields Reduce kick effect of pitched cavities by a factor of 2 Reduces emittance effect of pitched cavities by a factor of 4 Brings his results and ours into agreement for cavities Kubo-san’s study did include misalignments of sector bends in “quads and BPMs only” cases Has a nontrivial effect on emittance Added bend offsets to SLAC study, results reproduced Kubo-san’s Need to go back and do full studies with fully-agreed errors Should migrate to 2007 optics Different configurations of bends, RF stations Longer initial bunch (so worse effects expected) ILC R&D Meeting Global Design Effort
4
2006 Coupling Correction Cornell group found that putting decoupler near DRX and wire scanners near spin rotator (ie, far away from each other) does not work well Decoupler can zero <xy> but emittance, y dispersion blow up Observed some interplay with x dispersion correction Putting decoupler right next to wire scanners works very well Didn’t understand why Cornellians sent some files to play with ILC R&D Meeting Global Design Effort
5
2006 Coupling Correction (2)
Problem now understood Misaligned skew quads in decoupler, so tuning them introduces y oscillation Oscillation in turnaround dispersion In presence of x dispersion, adding y dispersion at wire influences <xy> term Complicated parameter space, since tuning skew quads changes betatron coupling and vertical dispersion, and can introduce nonzero <xy> due to x dispersion Raw minimization of <xy> probably not the best “You said zero <xy>, not minimize <yy>” 2007 design has decouplers near wire scanners ILC R&D Meeting Global Design Effort
6
DRX-RTML Junction Started to look at completing connection between DRX and RTML Requires layout of LTR and DRI as well All need to share a single tunnel Had to drop this temporarily Plan to complete prior to DESY meeting If still incomplete at that time, look for other people to do the work… ILC R&D Meeting Global Design Effort
7
RTML FY07 to-do list Connect RTML to DRX Tune up RTML geometry
Do that myself (hopefully) Tune up RTML geometry Cornell FY08-09 WP Tune up RTML matches (Re)Design extraction lines Interest in this at SLAC RF Parameters Static emittance tuning Best effort KEK + SLAC, maybe some CERN Space charge FNAL and LBL groups looking at this Stray fields Understand relevance of ML / RR experience to RTML Return line Cost estimate Like to do a fresh bottoms-up estimate at some point Don’t know if this is practical for FY07 Note: tasks which are “assigned” are in italics ILC R&D Meeting Global Design Effort
8
RTML (2.6) FY08-09 WPs prepared and presented to Mike and Gerry
Not too heavy on “R & D” as such More concentrated on engineering, esp. magnets and beamlines Packing fractions, etc. Some accelerator design work In particular some LEPP WPs in this area FY08: effort centered at SLAC and LEPP FY09: should perhaps look to add some partners inside or outside of US ILC R&D Meeting Global Design Effort
9
ML Design Nothing new to report since 28 Feb 2007
Planning to have completed e+ and e- lattices on June timescale Proper lengths Proper RF units Proper aperiodicities for cryo hocus-pocus Proper undulator insertion in e- side Vertical curvature Proper match out of RTML and into BDS ILC R&D Meeting Global Design Effort
10
ML (2.7) FY08-09 WPs prepared. Plan includes:
LRWF studies 2-2.2 SLAC FTEs RTML, ML, S2E sims, code development SLAC FTEs S-band BPM test in CM SLAC FTEs FNAL and LEPP also major participants NB: This represents a major jump in effort from what we are doing today in this area! ILC R&D Meeting Global Design Effort
Similar presentations
