View
222
Download
0
Category
Tags:
Preview:
Citation preview
WG1, Hannover, Jan 2007 1
Commissioning progress at Commissioning progress at GEO600GEO600
Martin Hewitson for the GEO teamMartin Hewitson for the GEO team
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 22
Overview - plansOverview - plans
Ended full-time S5 15 Oct 2006Ended full-time S5 15 Oct 2006• Back to commissioning, overnight/weekend modeBack to commissioning, overnight/weekend mode
Planned work:Planned work:• Investigation periodInvestigation period
Power measurements, simulation improvements, etcPower measurements, simulation improvements, etc
• ESD AA for MIDESD AA for MID• Improve clean-room cleanlinessImprove clean-room cleanliness
New HEPA filters for ACNew HEPA filters for AC
• Fix various mains problemsFix various mains problems Filtering, ground loops, PE to neutral connectionsFiltering, ground loops, PE to neutral connections
• Open central clusterOpen central cluster Exchange HV feedthroughs for ESDs (corroded)Exchange HV feedthroughs for ESDs (corroded) Reposition beam block (scattering suspected)Reposition beam block (scattering suspected)
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 33
Since the last meeting…Since the last meeting…
Investigations:Investigations:• Power build-upPower build-up• Power increase - instability, PUGsPower increase - instability, PUGs• ‘‘Ripple’ noiseRipple’ noise
Commissioning:Commissioning:• MID AA ESDsMID AA ESDs• SR longitudinal loopSR longitudinal loop
Problems:Problems:• Significant series of power failuresSignificant series of power failures
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 44
Not in this talkNot in this talk
Power up stability, glitchesPower up stability, glitches• Detector not stable with full available input power Detector not stable with full available input power
HOT TOPICHOT TOPIC
• Also observed large glitches in the past when at full powerAlso observed large glitches in the past when at full power Not observed recently so hard to investigateNot observed recently so hard to investigate
Ripple noise investigationsRipple noise investigations• See Josh’s talkSee Josh’s talk
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 55
Running performanceRunning performancePost S5 runningPost S5 running
Pow
er c
ut
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 66
PR build-upPR build-up
Two reliable methods used to determine Two reliable methods used to determine factor:factor:• PR cavity pole PR cavity pole • Direct measurement of power reflected from Direct measurement of power reflected from
BS AR coatingBS AR coating Additional measurements of power Additional measurements of power
transmitted at end mirrorstransmitted at end mirrors• Less reliable due to low light levelsLess reliable due to low light levels
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 77
PR cavity polePR cavity pole
Measurements of PR cavity pole giveMeasurements of PR cavity pole give
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 88
PR build-up - SummaryPR build-up - Summary
PR pole and BS-AR measurements agree within PR pole and BS-AR measurements agree within 10%10%• Yield a build-up factor of 840-920Yield a build-up factor of 840-920
Transmission at MFe gives build-up factor of Transmission at MFe gives build-up factor of 1410 (less confidence)1410 (less confidence)
Can be explained by 120-130 ppm/mirror
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 99
Site Power Failure - 02/12/06Site Power Failure - 02/12/06
3 power failures of increasing duration - last one around 3 power failures of increasing duration - last one around 40 minutes40 minutes
Various systems damagedVarious systems damaged• MC turbo pump, computers, ESDsMC turbo pump, computers, ESDs
North ESD damagedNorth ESD damaged• 2 pairs of wires shorted inside vacuum2 pairs of wires shorted inside vacuum
Diagnosed by current-limit of HVADiagnosed by current-limit of HVA Some external rewiring to bypass the problemSome external rewiring to bypass the problem
• Still less actuation after repairStill less actuation after repair 35% less on North drive, 65% less on East drive35% less on North drive, 65% less on East drive All quadrants on East are workingAll quadrants on East are working What else? Charges on test-mass counter-act the dielectric effect of What else? Charges on test-mass counter-act the dielectric effect of
ESD which means less forceESD which means less force
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1010
Charges on East test-massCharges on East test-mass
Lock with north onlyLock with north only Drive East drive with varying bias plus Drive East drive with varying bias plus
fixed ac (calibration) linefixed ac (calibration) line Measure line height in MID error-pointMeasure line height in MID error-point For un-charged test-mass line height For un-charged test-mass line height
should be zero for zero biasshould be zero for zero bias
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1111
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1212
Attempts to dischargeAttempts to discharge
UV attackUV attack• Shine UV into TCeShine UV into TCe
Knock of electrons from metal-workKnock of electrons from metal-work• neutralize test-massneutralize test-mass
Venting central cluster with argonVenting central cluster with argon• Vented to 1mbarVented to 1mbar
failedfailed
failedfailed
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1313
Going on after power cutGoing on after power cut
Decide to stick with lower strength ESDs Decide to stick with lower strength ESDs for now since we want to open vacuum for now since we want to open vacuum anyway soonanyway soon
Calibration adjusted to give old sensitivtyCalibration adjusted to give old sensitivty• Checked with PPDChecked with PPD
Loop gains adjusted for this stateLoop gains adjusted for this state So far seems not to cause too much So far seems not to cause too much
trouble for lockingtrouble for locking
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1414
Improving SR long lockImproving SR long lock
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Motivation:Motivation:• Want to try PRAA for higher powerWant to try PRAA for higher power
PR long noise couples to SR cavityPR long noise couples to SR cavity• Want more SR long gainWant more SR long gain
Current SR long state:Current SR long state:• Loop bandwidth is limited by how much feedback Loop bandwidth is limited by how much feedback
noise we can toleratenoise we can tolerate• Feedback is shot-noise above 100HzFeedback is shot-noise above 100Hz• Previously using the AA quadrant diode for long error-Previously using the AA quadrant diode for long error-
signalsignal• Installed SED resonant for 9MHzInstalled SED resonant for 9MHz
Expect x2 lower shot-noiseExpect x2 lower shot-noise
Motivation:Motivation:• Want to try PRAA for higher powerWant to try PRAA for higher power
PR long noise couples to SR cavityPR long noise couples to SR cavity• Want more SR long gainWant more SR long gain
Current SR long state:Current SR long state:• Loop bandwidth is limited by how much feedback Loop bandwidth is limited by how much feedback
noise we can toleratenoise we can tolerate• Feedback is shot-noise above 100HzFeedback is shot-noise above 100Hz• Previously using the AA quadrant diode for long error-Previously using the AA quadrant diode for long error-
signalsignal• Installed SED resonant for 9MHzInstalled SED resonant for 9MHz
Expect x2 lower shot-noiseExpect x2 lower shot-noise
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1515
Further improvementsFurther improvements
Noticed coherence through dSPACE is not Noticed coherence through dSPACE is not 11
Limited by DAC noiseLimited by DAC noise• First tried flat gain factor for feedback First tried flat gain factor for feedback • Then added whitening at feedback outputThen added whitening at feedback output
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1616
Using new SED for SR longUsing new SED for SR long
Lowers MSR Lowers MSR feedback projection feedback projection to Hto H• We can use this We can use this
gain to improve the gain to improve the control loopcontrol loop
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1717
New SR run-loopNew SR run-loop
Relax feedback low-Relax feedback low-pass filtering allows pass filtering allows more low-frequency more low-frequency gain for similar loop-gain for similar loop-stability marginsstability margins
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1818
Cleaning up the clean-roomCleaning up the clean-room
Additional HEPA Additional HEPA filters installed for AC filters installed for AC systemsystem
We have additional We have additional particle leak from particle leak from pump-room due to pump-room due to over-pressure thereover-pressure there
WG1, Hannover, Jan 2007WG1, Hannover, Jan 2007 1919
Coming upComing up
Opening vacuum systemOpening vacuum system• Reposition beam dump(s) and install Reposition beam dump(s) and install
translation stage(s)translation stage(s)• Repair ESDsRepair ESDs
Fix wiring and install new HV feedthroughsFix wiring and install new HV feedthroughs Improvement of air-conditioning systemImprovement of air-conditioning system
• HEPA filters in clean room HEPA filters in clean room [done][done] Continue work on power increaseContinue work on power increase Continue commissioning of MID ESD AAContinue commissioning of MID ESD AA
Recommended