We had a timing glitch at EY this afternoon. All the IOP processes were showing an IRIG-B offset. We restarted all the models and burt restored the SUS and SEI to the safe.snap files. Note that SUS ETMY and ISI BSC6 showed some burt restore errors indicating channels had changed and the safe.snaps need regenerating. The cause of the glitch is not known.

On an unrelated note, we noticed a strong hot plastic smell in the EY rack area, someone should perhaps check that is not serious.

Yesterday around noon the H1 laser shut down automatically. The error message was: NPRO shut down during running. This happend at least once before afte the H2->H1 move.

We had that problem at the AEI reference system a couple of time and could solve it by adding a UPS to filter the power line used by the NPRO driver. Since then we have not seen this problem again "more than one year".

Attached are plots of dust counts > .5 microns.

Remember that ridiculous offset for one of the PZTs (14 volts)?

That was coming from the channel four of the AI output. The input  of the AI was not connected to DAC (dumb), but anyway in that state it was outputing 17 volts differential, and it looked as if it was not balanced:

CH4+ - CH4- = 17 volt

CH4+ - CH3- = 14 volt

CH4- - CH3- = 3 volt

CH3+ - CH3- = 0 volt

or some such.

I used a scsi cable and a breakout board to short out the AI input for this channel and it didn't change.

We need this offset for the alignment (until we relieve it), so at the moment it is left as is.

Doug, Jason, Travis,Mark,Hugh and ISI team
The the previous days alignment was made with the control damping off when the yaw was corrected using HEPI. When we first set up this morning to correct the pitch angle the yaw value was ~100 urads CW and when we switch the damping on at the same time that Travis made an adjustment to correct pitch we noticed a jump in the yaw value to ~300 urad. Subsequent pitch adjustments did not effect the ~300 urad yaw pointing and it remained at ~300 urads. Our first thoughts were that when we turned the damping on today we induced a yaw drive due to some offset value. This wasn't the case. Mark Barton and I looked at the OSEM  trends and could easily identify the pitch adjustment steps and the yaw trends were pretty much flatlined showing only very minor changes.

The dial indicators on the ISI  and digital read outs suggest that no ISI/HEPI movement took place during the pitch adjustments.  

Rechecking the Brunson optical square, total station pointing and laser collimator showed to be consistent with the previous days position and setup. We checked this several times today as well.

It seems like something shifted with the SUS possibly or something we missed with the alignment hardware.

The report for HAM-ISI Unit #5 - Assembly Validation is now posted under the DCC for validation.

This unit was tested at the begining of the month with testing horizontal GS13s (alog #2802). These testing pods were replaced with production pods. All tests involving GS13s were performed again this week. This report is now waiting for approval. This Unit will then be our second HAM-ISI coming out of the staging building with a full set of production GS13s (the first one was HAM-ISI Unit #4).

Reports regading the Assembly validation of previous units at LHO are also available on the DCC:

HAM-ISI Unit #1 - Assembly Validation
HAM-ISI Unit #2 - Assembly Validation
HAM-ISI Unit #3 - Assembly Validation
HAM-ISI Unit #4 - Assembly Validation

D. Cook, J. Oberling, T. Sadecki

After yesterday's SEI adjustment, we had a chance to revisit the IAS alignment of the ETM.  While Jason was going through his standard pre-measurement setup, I took the opportunity to (attempt to) close the ringheater as it had been passed over in previous entrances.  After loosening (or so I thought) the 4 8-32 screws that attach the RH to the Quad lower structure, I attempted to position the halves of the RH into their closed position.  While 3 of the 4 sides were loose enough to move, one side was mysteriously bound so that I could not move it into place.  After searching for interferences that would prevent me from moving it, and finding none, I examined the attachment points.  To my surprise, I found that the RH was not attached to the lower structure with the standard RH attachment blocks (D090438), but rather simply with nuts and washers (which appeared to be stainless on stainless).  Due to the the way in which the lower structure bolts together, I was unable to get a wrench onto the nut, and therefore had to rely mostly on friction with the assistance of allen key pressed against one of the flats of the hex nut.  So, unfortunately, I was unable to fully close the RH or sufficiently tighten any of the hardware attaching it (not a danger of loose hardware per se, just not very tight).  Not much we can to about it at this point either (maybe get a custom end wrench to fit through the 5mm gap and reach the nut) and not sure it's critical for the OAT anyhow. 

The ETM was found this morning with its MEDM master switch OFF, and in some unknown, unannounced state of testing.  After sorting its status, we got the damping loops running so we could get accurate IAS readings.  After several iterations of adjustment/tripping watchdogs/turning damping back on, we left the damping loops ON after satisfactory alignment was achieved. 

Either during our adjustment of pitch today, or some other event not yet identified, the yaw of the suspension was knocked back out of spec @ ~300urad.  Pitch is now in spec (I'll leave it to Jason to post the real numbers).

First vacuum completed. Wipe-down started.

Powered down HEPI valve drive chassis and ±24V power going to HEPI Interface modules. Replaced R13 from a 2 KOhm resistor to a 33.2K Ohm resistor on D080521 units. This changes the gain of the L4C channels from 22 to 333, per document E1200420-v1. Tested units after mods, gain ~330. Reinstalled and powered up units, along with the HEPI valve drive chassis.
Serial numbers of units modified: S0900233, S0900152, S0900229, S0900199.

Jim, Corey, Hugo,

The following L4Cs were huddle tested after reception from shipment #3759:

• Vertical L4C #87
• Vertical L4C #14
• Vertical L4C #52
• Vertical L4C #132
• Vertical L4C #73
• Vertical L4C #41

Specra are attached.

Test data is availabe in the SVN.

Gerardo and I are attempting to align the optical lever, we are able to hit the ITM relatively easily but on the reflection back to the QPD, we get this terrible scattered pattern shown in the pictures attached.  We thought it might be the telescope so we switched it out and it just gives us a different scattered pattern with fringes.  It is clear that there are multiple reflections and fringes but we tried hitting all parts of the ITM to make sure we're not clipping somewhere and it doesn't change the pattern.  We also looked at the beam coming out of the telescope and it looks very circular and focuses down well, approximately 25 meters away the spot size looks about 2 or 3 mm in diameter.  So I'm confused, I'm thinking maybe during installation and de-installation the telescopes got bumped and need to be refocused(which I've never done before), or we're using the wrong ones all together.  Another weak point would be the fiber optic cable getting crimped, but there's a  possibility that we're hitting something inside the chamber is messing up our reflected beam (the pattern looks very similar to Van Gogh's Starry Night).  Investigating causes now.

Paul Schwinberg, Peter King, Rick Savage

We found that when we increased the gain of the frequency stabilization servo (Table-top Frequency Stabilization Servo - TTFSS D040105 Rev. B S/N LHO03) to achieve the required bandwidth of around 400 kHz the servo lost lock frequently and had difficulty re-acquiring lock.
Investigations with the RF spectrum analyzer revealed peaks in the Open Loop Transfer Function (OLTF) presumably from resonances in the phase-correcting EOM (Pockels cell) near 793 kHz and 1.8 MHz. (See OLTF.TIF, attached)

We loaded C16 = 150 pF and tuned the existing notch in the Pockels cell path to 793 kHz using C50. (See NOTCH.TIF, attached)

We then added a 20 pF fixed capacitor and a 25 pF variable capacitor in parallel wired in series with a 220 uH inductor and installed between the upstream side of L2 and Ground.  This was tuned to give a second notch in the PC path at 1.8 MHz. (See 2NOTCH.TIF, attached)

Then, by locking the TTFSS with only the FAST path (PC path disconnected), we found a peak in the OLTF at 35.7 kHz which is likely from the FAST actuator (piezo) in the NPRO. (See FASTONLY.TIF, attached)
We tuned the notch in the FAST path to 35.7 kHz after changing L3 to 1000 uH and C49 to 18 nF and 2.2 nF wired in parallel. (See FSTNOTCH.TIF, attached)

After some tuning with the TTFSS installed, the OLTF was measured with the TTFSS locked using only the FAST actuator. (See OLTFFAST.TIF, attached).
With both the FAST and the PC actuators connected, the crossover was adjusted and the loop UGF was set to about 400 kHz where we have about 50 deg. of phase margin and close to 20 dB of gain at 100 kHz. (See OLTF3.TIF, attached)


The loop operates robustly in this configuration.


Prior modifications:
As found (and verified):
R50 = 499 Ohm
C62 = 1000 pF
R44 = 4.75 kOhm
R41= 24.9 kOhm

Attached are plots of dust counts > .5 microns.

- Leak test at HAM1, HAM2
- Still pumping y-beam manifold
- SUS testing at EY, many alarms, watchdogs tripped all day
- ALS working with IAS at EY
- Ops: Meeting with PSL at 1pm tomorrow (Thursday)
- PSL: crew working late (past 6:00pm so far)
- Apollo - ICC, installing panel for Ski, backflow preventor for LDAS room
- ICC upper section of BSC2, cleaned about ring, moved flooring, half chamber bottom
- OpLev: Thomas aligning the OpLev beam on ITMY
- CDS: rebooted h1daq
- MichaelR replacing laser safety signs across the site
- Ongoing discussions about viewport acceptance and installation
- Temperature setpoint raised from 67-70F in LSB lab areas
- Aidan coming next week and wants laser hazard in some areas
- OSB doors locked at 4:15pm
- Heavy rain in the evening

I tested on H1 DAQ and then released it on H2 DAQ. Some DAQ restarts were necessary between 16:00 and 17:00 today.

New data concentrator startup code takes the current set of INI and PAR files and puts them into a location removed from the RCG modification area. All DAQ components (concentrator, frame writers and NDS) have been reconfigured to use the saved configuration set and not the default area. Now if a frame writer or nds is restarted after an INI PAR file change, they run with the saved configuration and not with the latest configuration, maintaining configuration sync between all DAQ systems.

Code change to /etc/init.d/daqd_dc0 on h1dc0 and h2dc0

...
daqdir="/opt/rtcds/lho/h1/daq"
...

	# Copy INI and PAR files to a secure location and create a master file which references them
	# This will permit restarts to frame writers and nds machines against the channel configuration
	# at the time of the data concentrator start, and prevent modified INI and PAR files from being used.
	# D.Barker 23May2012

	# INI and PAR files copied into a directory named by the current date-time
	# a symlink called running is pointed to the latest directory
	DATETIME='date +%d%m%y_%H:%M:%S'
	#echo "${DATETIME}"
	mkdir ${daqdir}/${DATETIME}
	rm -rf ${daqdir}/running
	ln -s ${daqdir}/${DATETIME} ${daqdir}/running
	for f in 'grep "^/opt" /opt/rtcds/lho/h1/target/h1dc0/master'
	do
	#echo $f
	cp $f ${daqdir}/${DATETIME}
	done

	# create new master file referencing this running configuration
	for f in ${daqdir}/running/*
	do
	echo $f >> ${daqdir}/running/master
	done
	# End of INI-PAR copy change. DB.

And the change to daqdrc file in all DAQ systems (h1 system shown):

...
set master_config="/opt/rtcds/lho/h1/daq/running/master";
...

3 of the ~20 joints tested to this point are big leaks -> Bolts of leaking flanges feel "wrong".  Bolt torque is uniform but bolts feel "soft" and far too compliant.  Not sure if they had yielded on initial install or maybe wrong alloy?  (Hex head silver plated - where did these come from?)

JimW EricA Greg

This morning we disconnected the HEPI Actuators because the YAW correction needed by IAS was ~200urads or about .4mm at the HEPI foot.  The range of motion is only +-1mm, plus, the attached actuators will fight that amount of motion and cause non-expected responses.  Jason tweaked up the IAS gear and gave us the confirm on moving.  We brought it from 180urad CCW to 15urad CCW with 1/4 of a turn on each of the big Double Start Counter Wound (DSCW) HEPI Springs.  After lunch we set to reattaching the Actuators and while we'd like to see better centering of the Actuator Plates for max range of motion I think it will be plenty.  We'll have to really do driven range of motion measurements to determine this.
In the end based on the Dial Indicators relative the last In-Chamber Vertical survey of the optical table and post this mornings move and OK by IAS, HEPI has Yawed the Optic from 15urad ccw to 35urad cw (still in spec).  We also improved the level of the optical table, depending on how the tilting of the HEPI actually translates into the tilting of the optical table, from 0.5mm p-p to 0.3mm p-p.  So again all good; really we just got lucky.

I've attached a few pages from my logbook recording the in-chamber vertical survey and all the HEPI DSCW Spring adjustments and the Dial indicators readings.  Let me know if you want a guide or tour.

Brushing of BSC2 was completed and first vacuum started.