md report: ip aperture scans

W. Kozanecki MDI meeting, 9 Mar 07

MD goalsMD goals

Experimental procedureExperimental procedure

HER-only x & y scans + high-current extrapolationHER-only x & y scans + high-current extrapolation

[LER only X & y scans] [LER only X & y scans] + high-current extrapolation+ high-current extrapolation

MD report: IP aperture scansMD report: IP aperture scans

P. Grenier, W. Kozanecki & M. Weaver

+ S. Ecklund's watchful eyes!


Quantify Babar Quantify Babar background sensitivitybackground sensitivity to IP x & y angles for to IP x & y angles for single beams (HER & LER separately, moderate currents)

collisions (moderate currents, then high currents)

and determine the and determine the optimum anglesoptimum angles (from the background (from the background viewpoint)viewpoint)

Cross-calibrateCross-calibrate LIPP & HIPP BPMs

Babar luminous & boost angles

against against support-tubesupport-tube (ST) BPMs (ST) BPMs

Determine LER IP Determine LER IP angles angles center of luminosity monitor center of luminosity monitor absolute angles (from ST BPMs) at moderate current

reference angles (from HIPP & LIPP), corrected for high-current operation

MD goalsMD goals


Locations of the IP BPMs & neutron monitorsLocations of the IP BPMs & neutron monitors

Neutron_bckw_1

Neutron_forw_1

Neutron_forw_2

CsI 7

Support-tube (ST) BPM HIPP BPM LIPP BPMLIPP BPM


(Intended)(Intended) Measurement SequenceMeasurement Sequence

SetupSetup colliding beams, offset by-2 patterns at 300 mA ea.

Single-beam scans: Babar onSingle-beam scans: Babar on HER

XP scan, then YP scan @ 300 mA, offset pattern

with XP & YP at optimum, raise IH 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 IL until ST BPMs saturated

Luminosity-monitor scans: Babar onLuminosity-monitor scans: Babar on YP(e+) scan attempted; failed bec. IP Multiknob fbk not functional

Current-dependence of ST-L/HIPP correlation in collisionCurrent-dependence of ST-L/HIPP correlation in collision most likely different from single-beam (heat from both beams)

Background scans @ high current: XP(eBackground scans @ high current: XP(e--), YP(e), YP(e++), XP(e), XP(e++), YP(e), YP(e--)) beam-beam tails behave diffferently from beam-gas


Experimental procedureExperimental procedure

Operating procedure: generalOperating 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 onInitial 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-) LER XP = 9.25 mrad (ST BPMS) YP = - 1.1 mrad (ST

BPMs)

HER XP = -16.7 mrad (ST BPMS) YP = + 1.1 mrad (ST BPMs)


HER-only scans: current- & angle historyHER-only scans: current- & angle history

HER current XP_ST (e-)

YP_ST (e-)YP_ST (e-) during XP scan


HER-only scans: ST vs HIPP BPMs @ 300 mAHER-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


HER-only XP scan (1a)HER-only XP scan (1a)

Normalized to HER-only prediction

BW dmd, normalized

TR-23 (EMC)

E-collim (PR12 9082)

x 2.6x 1.7

x 2.3


HER-only XP scan (1b)HER-only XP scan (1b)

PR02 VP7032

PR02 VP8020

PR02 VP8029

CsI 3054


HER-only XP scan (2a)HER-only XP scan (2a)

neutron fwd_1

SVT occpcy, = 0 (E)

SVT occpcy, = 180 (W)

x 2.7x 3.6

x 11


HER-only XP scan (2b)HER-only XP scan (2b)

PR02 VP7034

PR02 VP7042

PR02 VP8027

PR02 VGH_8027


HER-only YP scan (1a)HER-only YP scan (1a)

neutron bwd_1CSi7052

Xcoll PR12 7102 Ycoll PR12 8072


HER-only YP scan (1b)HER-only YP scan (1b)

SVT occpcy, = 0 (E)

SVT occpcy, = 180 (W)


HER-only YP scan (1c)HER-only YP scan (1c)

PR02 VP8027

PR02 VP8020

PR02 VGH_8027


HER-only YP scan (2)HER-only YP scan (2)

neutron fwd_1

TR-23 (EMC)

BW dmd, normalized

Normalized to HER-only prediction



neutron fwd_2 CSi3054

PR02 VP8024


High-current extrapolation: HER-onlyHigh-current extrapolation: HER-only

HER current XP_ST (e-)

YP_ST (e-)




PR02 VP8029


High-current extrapolation (HER-only): ST vs HIPPHigh-current extrapolation (HER-only): ST vs HIPP

XP (HIPP) vs. XP_ST (e+) YP (HIPP) vs. YP_ST (e+)

XP (HIPP)


High-current extrapolation (HER-only) (1a)High-current extrapolation (HER-only) (1a)

TR-23 (EMC)

BW dmd, normalized


Dynamic pressure


High-current extrapolation (HER-only): pressure samplingHigh-current extrapolation (HER-only): pressure sampling

Thermal outgassing


High-current extrapolation (LER-only): angles vs. IHigh-current extrapolation (LER-only): angles vs. I

XP_ST (e+)

YP_ST (e+)

LER current


High-current extrapolation (LER-only): ST vs. LIPPHigh-current extrapolation (LER-only): ST vs. LIPP

XP_ST (e+)

YP_ST (e+)

XP (YIPP) YP (LIPP)


To do…To do…

Document usable scan rangesDocument 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 subdetectorDetailed 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 temperaturesAnalyse temperatures

Analyse vacuum signaturesAnalyse vacuum signatures

Volunteers needed!Volunteers needed!


Summary (preliminary!)Summary (preliminary!)

Background sensitivity to single-beam aperture scans @ 300 mABackground 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/HIPPConsistency between ST BPM's & LIPP/HIPP much improved since run 5

degrades as current increases, esp. for LER XP

Luminosity monitor scanLuminosity 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 No reason to believe that this single-beam optimum will coincide with that for beam-beam tails: with that for beam-beam tails: need to explore XP & YP need to explore XP & YP optimization on both L and backgrounds under physics optimization on both L and backgrounds under physics conditions!conditions!


AppendixAppendix: CRR plot files & data sets: CRR plot files & data sets

PEP-II e-log: 5 March 2007 day + swing shiftPEP-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 filesCRR button files BBR_BKG_LERIPORB.btn

BBR_BKG_HERIPORB.btn

BBR_ALL_BKG.btn

All data in PHYSICS_DATA:[pep2.char.05mar07]All data in PHYSICS_DATA:[pep2.char.05mar07]

md report: ip aperture scans

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