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W. KozaneckiMCC AP meeting, 8 Mar 07 MD goals Experimental procedure HER-only x & y scans + high-current extrapolation [LER only X & y scans + high-current extrapolation] Angles, then & now Summary MD report: IP aperture scans P. Grenier, W. Kozanecki & M. Weaver + S. Ecklund's watchful eyes! Preliminary!
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W. KozaneckiMCC AP meeting, 8 Mar 07 Quantify Babar background sensitivity to IP x & y angles for single beams (HER & LER separately, moderate currents) collisions (moderate currents, then high currents) and determine the optimum angles (from the background viewpoint) and determine the optimum angles (from the background viewpoint) Cross-calibrate LIPP & HIPP BPMs Babar luminous & boost angles against support-tube (ST) BPMs against support-tube (ST) BPMs Determine LER IP angles center of luminosity monitor absolute angles (from ST BPMs) at moderate current reference angles (from HIPP & LIPP), corrected for high-current operation MD goals
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W. KozaneckiMCC AP meeting, 8 Mar 07 (Intended)Measurement Sequence (Intended) Measurement Sequence Setup colliding beams, offset by-2 patterns at 300 mA ea. Single-beam scans: Babar on HER XP scan, then YP scan @ 300 mA, offset pattern with XP & YP at optimum, raise I H as high as it will go, to measure current-dependence of support-tube (ST) - L/HIPP correlation LER XP scan, then YP scan @ 300 mA, offset pattern with XP & YP at optimum, raise I L until ST BPMs saturated Luminosity-monitor scans: Babar on YP(e + ) scan attempted; failed bec. IP Multiknob fbk not functional Current-dependence of ST-L/HIPP correlation in collision most likely different from single-beam (heat from both beams) Background scans @ high current: XP(e - ), YP(e + ), XP(e + ), YP(e - ) beam-beam tails behave diffferently from beam-gas
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W. KozaneckiMCC AP meeting, 8 Mar 07 Experimental procedure Operating procedure: general manual scans, CRR plots vs time (autoscan impractical: knobs not closed!) monitor angles with ST BPMs, LIPP/HIPP orbit fits & monitoring fbks monitor temps & vacuum throughout the scans trickle, Babar on (incl. DAQ, with background-enriched trigger) Initial setup: colliding beams, offset patterns, trickle, Babar on bunch patterns LER: by-2, 300 mA, buckets 400-3400. BPM measdef @ bucket 3200 HER: by-2, 300 mA, buckets 0-3000. BPM measdef @ bucket 200 private BPM calibrations for PR02 BPMS 7052 to 8012, 3024 to 2203 set initial IP angles based in May 2005 lumi-monitor settings (exc. XP - ) LERXP = 9.25 mrad (ST BPMS)YP = - 1.1 mrad (ST BPMs) HERXP = -16.7 mrad (ST BPMS) YP = + 1.1 mrad (ST BPMs) optimize luminosity on tunes
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only scans: current- & angle history HER currentXP_ST (e - ) YP_ST (e - ) YP_ST (e - ) during XP scan
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only scans: ST vs HIPP BPMs @ 300 mA XP (orbFit) vs. XP_ST XP (HIPP) vs. XP_ST YP (orbFit) vs. XP_ST YP (HIPP) vs. XP_ST
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only XP scan (1a) Normalized to HER-only prediction BW dmd, normalized TR-23 (EMC) E-collim (PR12 9082) IDRC normalized x 1.9 x 2.6 x 1.7 x 2.3 Normalized to HER-only prediction
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only XP scan (1b) PR02 VP7032 PR02 VP8020 PR02 VP8029 CsI 3054
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only XP scan (2a) neutron fwd_1DCH normalized SVT occpcy, = 0 (E) SVT occpcy, = 180 (W) x 2.7 x 2.5 x 3.6 x 11 Normalized to HER-only prediction
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only XP scan (2b) These pressure ratios are different from the associated background ratios! PR02 VP7034 PR02 VP7042 PR02 VP8027 PR02 VGH_8027
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W. KozaneckiMCC AP meeting, 8 Mar 07 Locations of the neutron monitors Neutron_bckw_1 Neutron_forw_1 Neutron_forw_2 CsI 7 J. Va'vra
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only YP scan (1a) DCH normalized SVT occpcy, = 0 (E) SVT occpcy, = 180 (W) Normalized to HER-only prediction
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only YP scan (1b) neutron bwd_1CSi7052 Xcoll PR12 7102 Ycoll PR12 8072
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only YP scan (1c) PR02 VP8027 PR02 VP8020 PR02 VGH_8027
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only YP scan (2) neutron fwd_1 DIRC normalized TR-23 (EMC) BW dmd, normalized Normalized to HER-only prediction
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only YP scan (3) neutron fwd_2CSi3054 PR02 VP8024
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W. KozaneckiMCC AP meeting, 8 Mar 07 High-current extrapolation: HER-only HER current XP_ST (e - ) YP_ST (e - )
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W. KozaneckiMCC AP meeting, 8 Mar 07 High-current extrapolation (HER-only): ST vs HIPP XP (HIPP) vs. XP_ST (e + )YP (HIPP) vs. YP_ST (e + ) XP (HIPP)
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W. KozaneckiMCC AP meeting, 8 Mar 07 High-current extrapolation (HER-only) (1a) DIRC normalized TR-23 (EMC) BW dmd, normalized E-collim (PR12 9082) Dynamic pressure
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W. KozaneckiMCC AP meeting, 8 Mar 07 High-current extrapolation (HER-only): pressure sampling Thermal outgassing
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W. KozaneckiMCC AP meeting, 8 Mar 07 High-current extrapolation (HER-only) (2) DCH normalized SVT occpcy, = 0 (E) SVT occpcy, = 180 (W) Dynamic pressure
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W. KozaneckiMCC AP meeting, 8 Mar 07 High-current extrapolation (LER-only): angles vs. I XP_ST (e + ) YP_ST (e + ) LER current
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W. KozaneckiMCC AP meeting, 8 Mar 07 High-current extrapolation (LER-only): ST vs. LIPP XP_ST (e + ) YP_ST (e + ) XP (YIPP)YP (LIPP)
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER angles, Aug 06 & now (HIPP) Data: HER single-beam scans, 300 mA, 7 Mar 07
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W. KozaneckiMCC AP meeting, 8 Mar 07 LER angles, Aug 06 & now (LIPP) Data: LER single-beam scans, 300 mA, 7 Mar 07 Note high ratios!
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W. KozaneckiMCC AP meeting, 8 Mar 07 To do… Complete LER-only analysis More sophisticated subdetector analyses Analyse temperatures Analyse vacuum signatures Volunteers needed!
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W. KozaneckiMCC AP meeting, 8 Mar 07 Summary (preliminary!) Background sensitivity to single-beam aperture scans @ 300 mA significant, may explain part of the discrepancy w/ Jan '04 norm'lztn; is different, in both magnitude & optimum, for different subdetectors. The overall background optimum is incompatible with the SR load, at least in the HER (LER tba) Subdetectors assemble in 'families' that depend on X/Y, HER/LER; within one scan, several sources are at work, depending on the direction of SR fans & local aperture restrictions. Consistency between ST BPM's & LIPP/HIPP much improved since run 5 degrades as current increases, esp. for LER XP Luminosity monitor scan could not be completed for lack of working IPO Multiknob feedback. Can the fast dither play the same role? We need to know the center! may yield LER IP angles different from the single-beam optimum. No reason to believe that this single-beam optimum will coincide with that for beam-beam tails: need to explore XP & YP optimization on both L and backgrounds under physics conditions!
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W. KozaneckiMCC AP meeting, 8 Mar 07 SPARES
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W. KozaneckiMCC AP meeting, 8 Mar 07 HER-only YP scan (4) E-collim (PR12 9082)
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W. KozaneckiMCC AP meeting, 8 Mar 07 Appendix: CRR plot files & data sets PEP-II e-log: 5 March 2007 day + swing shift See also http://www.slac.stanford.edu/BFROOT/www/Detector/Backgrounds/ApertureScan-05Mar07.html for scan times & ranges CRR button files BBR_BKG_LERIPORB.btn BBR_BKG_HERIPORB.btn BBR_ALL_BKG.btn All data in PHYSICS_DATA:[pep2.char.05mar07]
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