U. Wienands, Y. Cai, F.-J. Decker, M. Donald, W. Kozanecki, Yu. Nosochkov, T. Raubenheimer, J. Safranek, D. Sagan., A. Seryi, K. Sonnad, C. Steier, P. Tenenbaum, A. Terebilo, J. Turner, M. Venturini, A. Wolski, M. Woodley, Y. Yan, G. Yocky, M. Zelazny PEP-II Lattice & Optics Progress

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug-04 2 Progress: New Tools Model lattice for given config about measured orbit Updated Online Phase-Advance Package Online Coupling (C 12 ) Analysis Orbit-Response-Matrix Analysis Fudge-Factor Configurations

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug-04 3 Progress: Ring Optics The HER got steered! Coupling in both rings monitored routinely –appears to be ok in LER –global coupling wave in HER ß y * got reduced in both rings to ≈1 cm ß x * in LER got reduced to 33 cm, match HER A 90° lattice for the HER is designed –ps parameters known, working on implementation

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug-04 4 Online Phase Advance MHD interpolation algorithm now standard –Good results for HER and LER –much more robust against noisy data C 12 analysis integrated with package Wave fits possible for ß and for C 12, Together with Colocho’s macros, this measurement is now vastly faster than before –important for machine characterization

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug-04 5 HER Coupling… raw C 12 (bar) HER Coupling… C 12 (bar) – fit wave Note how Solenoid comp. is non-closed Data of 10-Jun

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug-04 6 HER C 12 … Design M. Donald

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug-04 7 LER Coupling… raw C 12 (bar) LER Coupling… C 12 (bar) – fit wave Note better closure of solenoid compens. Data of 10-Jun before ß change

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug-04 8 LER C 12 … Design M. Donald

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug-04 9 HER Coupling 18-Sep-04

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug Ring Characterization Ph.-Advance, , ∑, Orbits about once/3 weeks –When indicated add MIA, ORM, CTA –Historical trend for these variables Monitor & correct (if applicable) lattice –Get idea about significance of changes Guidance to schedule ß changes etc.

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug HER ß y * HistoryLER ß y * History LER ß x * HistoryHER ß x * History G. Yocky

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug ∑ x History ∑ y History Steering Knob Recalib.

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug ORM Data Analysis We have HER and LER models in AT (LOCO) We have data sets for both rings for reasonably current configurations, together with phase-advance & MIA data The analysis gives ß functions & tunes in agreement with phase-advance We have derived magnet values from ORM

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug HER Magnet Factors P. Tenenbaum

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug Fudge-Factor Configurations We have now Fudge-Factor Configs. They modify the magnet-family strengths before handing them to the model Goal is to get config. model to agree with measurement

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug Fudge-Config Example

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug HER Steering The HER was steered in Jan. right after the xmas break Steered HER; - target = flat everywhere (incl. Str. 10 on-axis, IR2 sexts), except: PR12 collimators, HTFB (reset to hitorical values) IP parameters (X = 1000 mu, Y = 3000 mu, XP = murad, YP = 1500 murad) - achieved: etay rms mm, etay* = -1.7 mm. coupling = 1.5 kHz after restoring sym. component of IR2 sexts + decoupling w/ global skewsuads low-current collisions: CapSigMax * CapSigmin = 167 * 6.3 mu (23% gain in IP spot size) PEPlog excerpt:

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug-04 18

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug ß y * Reduction In the HER, used quads at the far ends of Arcs 1 & 3 (Yuri knobs) –local chromaticity correction preserved In the LER, we cannot do that –Use Q{F,D}BM & fix chromaticity (MHD, JLT) Both worked successfully Both rings now close to ß y *=1 cm There is a question about the HER global ß y behavior: not as predicted from knob test.

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug HER before May-4 ß y * reduction Note ß y * is 1.26 cm HER after May-4 ß y * reduction Note ß y * is 1.14 cm

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug HER ß y * Knob—Design M. Donald

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug Tune knob & ß beat HER tune knobs were characterized –calibration, ß x beat Calibration & orthogonality are good ß x beat changes significantly with x –follows 1/( x -0.5) ß y beat does not change

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug ° HER Lattice Reduce bunch length to 83% comp. to 60° –momentum compaction >.00168….0017 Put  beat back in =>  x =48 nmr –Can probably be taylored to bunch current May keep µ y at 60° => lower magnet strength Dynamic aperture is acceptable Power supply parameters determined

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug HER 90° Lattice Dispersion Yu. Nosochkov

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug HER 90° Lattice Dynamic Aperture Yu. Nosochkov

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug Some Open Issues HER coupling not quite right, needs fixing –(or is it needed to make vertical emittance?) HER ß y does not look like it should, why? –QDS0XS appear to be able to fix this Where does the drift in ß (y) come from? –given that we control the orbit well… Config model & ORM model in MAD get coupling wrong

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug More Issues… Once the config & ORM lattices are right (i.e. we have good fudge factors) –assess effect of the optics on beam emittance coupling, dispersion –assess dynamic aperture of actual lattices –use these lattices to design knobs

U. Wienands, SLAC-PEP-II PEP Run 4 WS: Optics, 4-Aug (Pre-) Run 5 Optics Tasks I’d like to be in a position to –Steer the LER successfully => need strategy to deal with effect on ß x –Fix ß beats in both lattices probably essential to lower x -> 0.5 may allow increased beam-beam tune shift requires a useable set of fudge factors We need ß*=33 cm/1 cm design lattices We need working x emittance knobs –no side effect on coupling or other plane