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W. KozaneckiMDI meeting, 9 Mar 07 MD goals Experimental procedure HER-only x & y scans + high-current extrapolation [LER only X & y scans] + high-current extrapolation MD report: IP aperture scans P. Grenier, W. Kozanecki & M. Weaver + S. Ecklund's watchful eyes!
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W. KozaneckiMDI meeting, 9 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. KozaneckiMDI meeting, 9 Mar 07 Locations of the IP BPMs & neutron monitors Neutron_bckw_1 Neutron_forw_1 Neutron_forw_2 CsI 7 LIPP BPM Support-tube (ST) BPM HIPP BPM LIPP BPM
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W. KozaneckiMDI meeting, 9 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. KozaneckiMDI meeting, 9 Mar 07 Experimental procedure Operating procedure: general manual scans, CRR plots vs time 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 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)
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W. KozaneckiMDI meeting, 9 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. KozaneckiMDI meeting, 9 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. KozaneckiMDI meeting, 9 Mar 07 HER-only XP scan (1a) Normalized to HER-only prediction BW dmd, normalized TR-23 (EMC) E-collim (PR12 9082) x 2.6 x 1.7 x 2.3
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W. KozaneckiMDI meeting, 9 Mar 07 HER-only XP scan (1b) PR02 VP7032 PR02 VP8020 PR02 VP8029 CsI 3054
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W. KozaneckiMDI meeting, 9 Mar 07 HER-only XP scan (2a) neutron fwd_1 SVT occpcy, = 0 (E) SVT occpcy, = 180 (W) x 2.7 x 3.6 x 11
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W. KozaneckiMDI meeting, 9 Mar 07 HER-only XP scan (2b) PR02 VP7034 PR02 VP7042 PR02 VP8027 PR02 VGH_8027
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W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (1a) neutron bwd_1CSi7052 Xcoll PR12 7102 Ycoll PR12 8072
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W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (1b) SVT occpcy, = 0 (E) SVT occpcy, = 180 (W)
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W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (1c) PR02 VP8027 PR02 VP8020 PR02 VGH_8027
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W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (2) neutron fwd_1 TR-23 (EMC) BW dmd, normalized Normalized to HER-only prediction
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W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (3) neutron fwd_2CSi3054 PR02 VP8024
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W. KozaneckiMDI meeting, 9 Mar 07 High-current extrapolation: HER-only HER current XP_ST (e - ) YP_ST (e - )
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W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (4) E-collim (PR12 9082) PR02 VP8029
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W. KozaneckiMDI meeting, 9 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. KozaneckiMDI meeting, 9 Mar 07 High-current extrapolation (HER-only) (1a) TR-23 (EMC) BW dmd, normalized E-collim (PR12 9082) Dynamic pressure
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W. KozaneckiMDI meeting, 9 Mar 07 High-current extrapolation (HER-only): pressure sampling Thermal outgassing
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W. KozaneckiMDI meeting, 9 Mar 07 High-current extrapolation (LER-only): angles vs. I XP_ST (e + ) YP_ST (e + ) LER current
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W. KozaneckiMDI meeting, 9 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. KozaneckiMDI meeting, 9 Mar 07 To do… Document usable scan ranges first pass (PG) @ http://www.slac.stanford.edu/BFROOT/www/Detector/Backgrounds/ApertureScan-05Mar07.html supply tables of XP(LER/HER, ST BPMS) vs. time stamps Detailed analysis for each subdetector SVT occupancies, DCH current + occupancies, DIRC scalers & currents - use normalized quantities (2004) wherever possible clean up data sets (e.g. remove spikes associated with LER LFB problems, with knob turning, etc) how well does the 'family' concept hold? Analyse temperatures Analyse vacuum signatures Volunteers needed!
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W. KozaneckiMDI meeting, 9 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) There may be subdetectors '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. KozaneckiMDI meeting, 9 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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