of the LIGO Detector
LIGO Hanford Observatory
University of Tokyo
July 12, 2002
Hanford Observatory (LLO)
Livingston Observatory (LLO)
LIGO Hanford Observatory
Scientists Resident at Grad Students Support Staff
LHO » Bill Butler – Rochester » Dave Barker – CDS
» Dick Gustafson – UM » Masahiro Ito – UO » Greg Mendell – LDAS
» Michael Landry – postdoc » Rana Rakhola – UO » Richard McCarthy –
» Fred Raab – Head LHO Elect.
» Rick Savage Operators
» Josh Myers – Elect.
» Paul Schwinberg » Betsy Bland
» Doug Cook – Optics
» Daniel Sigg » Corey Gray
» Kyle Ryan – Vac.
Visiting Scientists » Mark Guenther
» John Worden – Vac.
» Stan Whitcomb – CIT » Nathan Hindman
» Bartie Rivera –Vac.
» Robert Schofield – UO » Mark Lubinski
» Nergis Mavalvala – MIT » Gerardo Moreno
» Christine Patton – Sys.
» Peter Fritschel – MIT » Hugh Radkins Admin.
» Rana Adhikari – MIT » Cheryl Vorvick » Otto Matherny –
» Bill Kells – CIT
» Jill Berry – Admin.
» Luca Matone - CIT
LHO Daily Schedule
Operators on site seven Electronic log book (elog) for
days per week. all detector-related activities.
» Two shifts per day » Available on the web
– 7:00 AM to 5:00 PM http://blue.ligo-wa.caltech.edu/ilog/
– 4:00 PM to 2:00 AM
Some increased seismic noise
» Two operators per shift
due to construction of new
Electronics troubleshooting, building
cabling, system maint., etc. » Typically 6:30 AM to 3:30 PM
typically in the mornings.
High winds (> 25 mph) usually
Begin operation of make full lock difficult, if not
interferometers at about 2:00 impossible.
Hanford Control Room
No electronics racks
in this room
Epics Control System
-All control via
-Digital length and
of input matrix in
(ala M. Evans)
4k Digital Suspension Control
Lots of digital filter
» Whitening and
» Resonant gain stages
LIGO Control and Data System
(D. Barker at LHO)
12,770 “slow” EPICS 3 MB/sec per ifo. written to
channels per interferometer frames
(LHO 4k ifo. with digital 15 TB of full-frame storage
suspension controllers) capacity at LHO
425 “fast” channels per ifo. --> Previous 390 hrs. or
(256 Hz, 2 kHz, 16 kHz) 16.25 days of data available
60 16-kHz channels per ifo. on disk
16 CDS computers (IOCs) Past 25 days of second-
per ifo. trend data available on disk
All past minute-trend data
available on disk
Automation of Interferometer
Common mode transition script
(D. Sigg) Automated initial alignment
# Turn MICH and PRC boost on
excawrite -b -r "H2:LSC-MICH_SW1R" -l "SET" "H2:LSC-MICH_SW1" 0000000000010000
ezcawrite -b -r "H2:LSC-PRC_SW1R" -l "SET" "H2:LSC-PRC_SW1" 0000000000010000 sleep 2
# Turn servo gains to final values
ezcawrite "H2:LSC-DARM_ERR_K" -1.2
ezcawrite "H2:LSC-CARM_ERR_K" -1.0
ezcawrite "H2:LSC-MICH_ERR_K" -0.085
ezcawrite "H2:LSC-PRC_ERR_K" -0.15 sleep 1 # # Set CM initial state
ezcawrite -b -r "H2:LSC-CM_SELECT_RD" -l "XOR" "H2:LSC-CM_SELECT" 01000001000000
ezcawrite H2:LSC-CM_OVERRIDE 0
ezcawrite H2:LSC-ComMode_CommGainIn 1
ezcawrite H2:LSC-ComMode_AOGainIn 11
ezcawrite H2:LSC-ComMode_ALGainIn 3
ezcawrite H2:IOO-MC_ERR_EXC_ENABLE 0
ezcawrite H2:IOO-MC3_LSC_IN 1
ezcawrite H2:LSC-ComMode_OpenLoop 1
“One-click” Generation of
Calibrated Spectra (M. Landry)
– uses most recent
calibrations DTT software package
– makes swept sine by D. Sigg
from TM drive
– pole-zero fit using
– measures AS_Q
LHO 2k Interferometer Status
5 Watts laser power Tidal prediction applied to
delivered to modecleaner. reference cavity
» Attenuation at AS port gives 20- temperature.
40 mW effective power
Recycling factor 15-25 Fine actuators (PZTs on
» Contaminated optic? ETM stacks) used for
Analog suspension residual tidal compensation.
controllers. First part of intensity
Only WFS 1 active stabilization loop is active.
» Improved optical lever damping Automated calibration.
Common-mode servo Multi-hour locked stretches,
configuration changed (now often 6-10 hours.
similar to TAMA)
Hanford 2k Ifo.
LHO 4k Interferometer Status
1 Watt laser power delivered Tidal prediction to reference
to modecleaner cavity temperature
» 20 mW effective at AS port
Fine actuators on ETM
Recycling factor 40-50
stacks for balance of tidal.
controllers Inner loop of intensity
» Lots of digital filter stages stabilization active.
» Frequency-dependent Lots of code changes.
diagonalization of drive of TM
drives Shakedown of digital
Only WF1 active suspension code now
Original common-mode (almost) complete.
servo configuration Now locking for up to 8
Hanford 4K Ifo.
LLO 4k Interferometer Status
1.9 Watt laser power to MC. Feed-forward to ETMs to
Recycling gain ~ 50. reduce large microseism.
Analog suspension Inner loop of intensity servo
Original common-mode Unable to lock during logging
servo configuration. – most weekdays.
Closed-loop control of ref. Adversely affected by traffic
cavity temp. for CM tides. on highway.
Fine actuators for residual Lock broken by trains twice
tidal correction. nightly.
PEPI to reduce 0.3 –5 Hz Locking for multi-hour
seismic noise at ETMs stretches when noise allows.
Livingston 4k Ifo.
Interferometer noise modeling
EO shutter at AS
port attenuates light
by factor of 50
New optical lever
should reduce ADC
noise by factor of
Below 15 Hz, freq.
noise resulting from
2k Sensitivity Improvement:
Reconfiguration of CM servo
Original configuration of frequency stabilization topology
From Nergis M.
Reconfiguration of Common-mode
Servo (D. Sigg)
Eliminate CARM drive to ETMs
MC servo feedback to laser frequency actuator only
From Nergis M.
Improved Displacement Spectrum
Relative Intensity Noise
4k laser current shunt xfer. fctn.
Free-running slow power
Insufficient drive range, D.C level = 1.7 V 0.37%/V
causing power glitches Design range > +,- 2.5%
(with Y. Aso, 5/02)
New Intensity Stabilization Servo
New two-loop servo
LHO 4k Outside-the-loop RIN Spectra
and new low-noise
Inner loop with PD just
Outer loop with PD just
RIN goal: 1e-8/rtHz
Only inner loop
installed, June, 2002
+,- 10 V drive range Stabilized
DP/P = 5e-8 Hz-1/2
LHO 4k RIN Spectra
Gain ~ 30 dB at 1 Hz
RIN not yet measured downstream
of MC with this servo.
Grounding and EMI
60 Hz and harmonics servo error point
» Green – laser power supply in
» Red – laser power supply
moved to top of PSL enclosure
Measurement made with RM
aligned and other optics
1 Hz period indicates small
6 fringes >> 3 micronspeak
Tried to identify which optic
moving by changing
damping gains – no change
because edge is below
Source of Parasitic Interferometer
Non-stationary noise Post MMT2 slippage
from parasitic ifo. investigation
» “uncovered an unsettling
scenario. From the plots, SM1
has been without it's
photodiode sensor readbacks
(and damping) since
Measured downstream ~12/18/01.” J. Myers July1, 2002 elog
of modecleaner entry
Delay of S1 Run
Friday, June 28, 2002
2k mode-matching telescope small optic
pitch monitor channel
LHO x-end vertical seismometer channel
peak to peak vertical velocity in
the spike is 80 microns/sec
Slack MMT2 Suspension Wire
Repair of MMT2 Suspension
“A preliminary inspection of mirror Working hypothesis is that
MMT2 shows two broken
the loss of control of one of
magnet assemblies. The wire
break is along the free section the other optics (SM2)
of wire, not in the clamp. The caused the laser beam to hit
optic is on its way to the optics the suspension wire of
lab for a post-mortem and MMT2, precipitating the
repairs. Chamber door is going breakage.
back on and we hope to be Tests of breaking wires
under load with hot irons
Fred Raab7/2/02 appear to support this
Earthquake stops did not hypothesis.
prevent magnet breakage – New baffles to protect
re-design underway. suspension wires designed
New Baffles to Protect Suspension
Wires from Laser Beams
New baffle Baffle
MMT2 repaired and re-
Waiting for water vapor
pressure to decrease
Pumpdown began at 12:35 so that gate valves to
PST on July 9. beam tubes can be
Fit to early Preliminary alignment,
pumpdown centering on Faraday
trend isolator, etc., looks
1e-7 torr It looks like the S1 run
on July 18 will begin the day after
the LSC meeting on
August 23, 2002.
After the S1 Run
Still lots to be done! Many pending hardware and
software installation tasks
P. Fritschel 6/02
LIGO Run Plan
Science 1 run – Upper Limits “During 2003 and 2004,
» June 29 to July 15 (Delayed) we will plan to run in this
» 2.5 weeks comparable to E7 search mode for at least
» Target sensitivity: 200x design 50% of the calendar time,
Science 2 run – Upper Limits followed by the planned
» Nov. 22 to Jan. 6, 2003 one year integrated LIGO
» 8 weeks science run at design
» Target sensitivity: 20x design sensitivity. This science
Science 3 run – Search Run run will be completed prior
» July 1, 2003 to Jan. 1, 2004 to proposed major
» 26 weeks interferometer
» Target sensitivity: 5x design replacements.”
LIGO Lab Planning Memo.