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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.

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Presentation on theme: "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."— Presentation transcript:

1 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!

2 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

3 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

4 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

5 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)

6 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

7 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

8 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

9 W. KozaneckiMDI meeting, 9 Mar 07 HER-only XP scan (1b) PR02 VP7032 PR02 VP8020 PR02 VP8029 CsI 3054

10 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

11 W. KozaneckiMDI meeting, 9 Mar 07 HER-only XP scan (2b) PR02 VP7034 PR02 VP7042 PR02 VP8027 PR02 VGH_8027

12 W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (1a) neutron bwd_1CSi7052 Xcoll PR12 7102 Ycoll PR12 8072

13 W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (1b) SVT occpcy,  = 0 (E) SVT occpcy,  = 180 (W)

14 W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (1c) PR02 VP8027 PR02 VP8020 PR02 VGH_8027

15 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

16 W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (3) neutron fwd_2CSi3054 PR02 VP8024

17 W. KozaneckiMDI meeting, 9 Mar 07 High-current extrapolation: HER-only HER current XP_ST (e - ) YP_ST (e - )

18 W. KozaneckiMDI meeting, 9 Mar 07 HER-only YP scan (4) E-collim (PR12 9082) PR02 VP8029

19 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)

20 W. KozaneckiMDI meeting, 9 Mar 07 High-current extrapolation (HER-only) (1a) TR-23 (EMC) BW dmd, normalized E-collim (PR12 9082) Dynamic pressure

21 W. KozaneckiMDI meeting, 9 Mar 07 High-current extrapolation (HER-only): pressure sampling Thermal outgassing

22 W. KozaneckiMDI meeting, 9 Mar 07 High-current extrapolation (LER-only): angles vs. I XP_ST (e + ) YP_ST (e + ) LER current

23 W. KozaneckiMDI meeting, 9 Mar 07 High-current extrapolation (LER-only): ST vs. LIPP XP_ST (e + ) YP_ST (e + ) XP (YIPP)YP (LIPP)

24 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!

25 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!

26 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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