Michael, Krishna

This morning, we started the pump-down of BRS-2 by temporarily removing the safety interlock valve, which exists to prevent back-filling of the vacuum in case of a power outage. We expect to pump down with the cart in a day or two and switch to the ion pump, so this arrangement is okay.

Michael and I then placed 3 sets of Piezo stacks under the BRS-2 platform. We then drove the piezo stacks using the Beckhoff DAC module and an amplifier (0-100 V).

The tilt-transfer function measurement consists of driving the platform in pure rotation and measuring the response signal in the autocollimator, at a few frequencies. As the BRS-2 is connected to the pump and is not thermally shielded yet, the low-frequency noise is substantial, hence the measurement takes several hours. The attached pdf shows the measurement and a model assuming d = 10 microns (d is the distance between the center of mass (COM) and the pivot, with positive indicating COM below the pivot). The transfer function is shown relative to the drive which was roughly 1.7 microradian amplitude.

Plan for tomorrow:

1. Open the vacuum can and shift the COM up by ~10 microns.

2. Close up and begin pump down again. Remeasure the tilt-transfer function.

Dave, Nutsinee

TJ spotted the DIAG_MAIN guardian EZCA error (fail to grab a HWS channel) since this morning but we thought it's going to resolve itself. By evening the problem still persisted. Then Dave found out that the hwsmsr computer was crashed. We restarted the machine and re-ran the HWS codes for both ITMX and ITMY. ITMX had low peak counts when we restarted it. I stopped the code, turned the camera and fram grabber off and on then re-ran the code. That seems to have fixed the problem. I attached the image of the ITMX HWS before (low peak counts) and after camera restart (taken when the code wasn't running).

The end station chiller cleaning is on going. We ran out of water at End-X before the second chiller could be completed so we relocated to End-Y. I have called for a water delivery but that is not expected until Friday. We are and have been only running one chiller at each end station and the idle chiller at each station has been cleaned so I have switched units at each station. Chiller 2 at EX and Chiller 1 at EY are the ones currently running.

TITLE: 03/28 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Jim
SHIFT SUMMARY: Struggling to get past DRMI locking most of the day due to ASC issues.  Jenne has been parked in the OPS station helping me out.  An EQ before lunch didn't help and took ~2 hours to ring down.
LOG:
16:26 Jeff B to EX

19:00 Jeff B back

19:19 Karen leaving EY

19:44 Chandra to EX checking pump cart

19:57 Jeff B to EX

19:57 TJ done with charge measurements

21:18 Chandra back, going to MY with John, Bubba

21:26 Krishna and Michael to EY

21:39 Chandra done at EY

Moved pump cart from Ymid to LVEA to connect to RGA for testing

I took charge measurements at both ends today, they finished around 12:50 local. I'll post plots soon.

Following up on this earlier study, Weigang Liu has tried folding some of the
corner-station magnetometer data in 8-second intervals, day-by-day, month-by-month and over nearly the full O1 run
(excluding January because of commissioning work and October 20 for some channels because of anomalous data).

Attached are the summary plots, while links to the daily & monthly plots are here:

H1:PEM-CS_MAG_LVEA_VERTEX_X_DQ
H1:PEM-CS_MAG_LVEA_VERTEX_Y_DQ
H1:PEM-CS_MAG_LVEA_VERTEX_Z_DQ
H1:PEM-CS_MAG_EBAY_SUSRACK_X_DQ
H1:PEM-CS_MAG_EBAY_SUSRACK_Y_DQ
H1:PEM-CS_MAG_EBAY_SUSRACK_Z_DQ

As before, each figure has a top graph with the raw folded (averaged) data,
a middle graph with the spectrum of the folded data, and a bottom graph
which is the inverse FFT of the lowest 40 Hz. 

Remarks:

These graphs are qualitatively similar to those seen before for some EY magnetometer channels
in that there is a 2-second periodicity with a positive excursion at a 1-second boundary, followed by
a negative excursion at the next 1-second boundary.
There is additional fine structure more visible in these channels, most notably an extra transient seen
at the 0.25-second mark in successive 1-second intervals of the CS_MAG_EBAY_SUSRACK_(X/Y/Z) channels. 
The fine structure is seen throughout O1.

Laser Status:
SysStat is good
Front End power is 30.88W (should be around 30 W)
Frontend Watch is GREEN
HPO Watch is RED

PMC:
It has been locked 6.0 days, 0.0 hr 15.0 minutes (should be days/weeks)
Reflected power is 2.987Watts and PowerSum = 24.26Watts.

FSS:
It has been locked for 0.0 days 2.0 h and 26.0 min (should be days/weeks)
TPD[V] = 1.407V (min 0.9V)

ISS:
The diffracted power is around 9.374% (should be 5-9%)
Last saturation event was 0.0 days 2.0 hours and 26.0 minutes ago (should be days/weeks)

• BRS at EY is installed and pumping down
• Model upgrades planned for tomorrow for QUAD, ISI, OAF, and BS
• Vac preps for next weeks vent of HAM 6
• Sno Valley spring cleaning of chillers, first EX, then EY
• Terry Gunter is gone for 2 weeks, Christina filling in for her
• vent planned next week for HAM 6

Tues. maintenance planned tasks:

• PSL guardian fix implemented by TJ
• craning cleanrooms over BT for vent
• LN2 delivery
• Kiwamu working on TCS

TITLE: 03/28 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    Wind: 12mph Gusts, 8mph 5min avg
    Primary useism: 0.14 μm/s
    Secondary useism: 0.19 μm/s
QUICK SUMMARY: Arrived this morning to find the IFO unlocked with many things tripped (TMSX, TMSY, ETMY, EY ISI, EX ISI, IY ISI, IX ISI WDs tripped).  It appears this was due to a pair of EQs in Mexico during the night.  Reset all WDs and began initial alignment.

During Maintenance March 15th, IM1, IM2, IM3 and IM4 all shifted alignment for the same given alignment drive.  The first shift was identified and restored, but the next two shifts were not, and IM2 pitch, H1's biggest shifter, jumped about 40urad in the same direction, so a total of about 80urad alignment shift in pitch.

I restored the alignments (including IM4) to the values before the alignment shifts March 15th.  I did so by moving each optic and leaving some time between each, so I could get a reading of how much each optic (IM1-3) changed IM4 Trans QPD.

The results are that IM4 Trans QPD is:

• 6x more sensitive to IM1 p than IM3 p
• 2x more sensitive to IM2 p than IM3 p
• 10x more sensitive to IM1 yaw than IM3 yaw
• 4x more sensitive to IM2 yaw than IM3 yaw

This suggests that the tolerance for alignment shifts on IM1 need to be smaller than the tolerances we use for IM3.  

Currently we're using a tolerance of 5urad on all IMs, and I would suggest tightening that up for IM1 to 1urad tolerance for both pitch and yaw.

This week:

• ASC work
• Re-establishing 25W operations
• Laser intensity variation tests (e.g., ITM centering)

Week 4/4:

• PSL high power work
• POP_X signal chain  checkout
• HAM6 vent to install GS13 and spring blade dampers
• Currently not planned: Installation of high QE PDs and fast shutter replacement

J. Kissel

Joe Betzwieser has created some new bit of "user" c-code in order to facilitate getting the ISI's GS13s, projected into SUSPOINT longitudinal, to the corner station to be further projected into the IFO's cavity length basis. The code serves to mux multiple low-sampling rate channels (in this case, SEI channels) into one high-sampling rate channel for shipping over the RFM IPC with less overhead. See T1600083 for details.

To absorb this new code for incorporation into the PEM model (as per the plan, see LHO aLOG 26249 and ECR E1600028), I've updated the 
${userapps}/cds/common/src/
directory of the local copy of the cds_user_apps repository.

--------------------------
Exactly what has been received:

jeffrey.kissel@opsws2:/opt/rtcds/userapps/release/cds/common/src$ svn up
A    LOW_FREQ_MUX.c
A    ccodeio.h
A    MAX_MIN_CALC.c
A    LOW_FREQ_DEMUX.c
Updated to revision 12938.
jeffrey.kissel@opsws2:/opt/rtcds/userapps/release/cds/common/src$

Pressures still falling:

HAM 7/8:   5.6e-6 Torr (Friday=8e-6 Torr)
HAM 9:      3.8e-6 Torr (Friday=6e-6 Torr)
HAM 11/12:  3.5e-6 Torr (Friday=5e-6 Torr)

Then turned available annulus IPs ON:

HAM 8:   7 mA (pressure at cart jumped to 9.6e-6 Torr)
HAM 9:   full scale with red light (pressure at cart jumped to 5.5e-6 Torr)
HAM 11:  full scale with red light (pressure at cart jumped to 4.2e-6 Torr) 

Need power and signal cables for IPs on HAM 7 & 12. Power cord on HAM 8 is sketchy with tears in outer insulation. I've asked Phil to replace it.

Continue to monitor pressures to detect any potential outer o-ring leaks.

We did a little bit of ASC work today.  

First, while Kiwamu was running a TCS test I started a script to automate phasing of the WFS.  It uses the lockin, first runs a servo to set the phase of the lockin demod, then servos to minimize some signal.  We have it set up right now to phase the refl WFS to minimize the PR2 pit signal in Q for both REFL 9 and 45, and to minimize the SRM pit signal in AS 36 Q.  There is some code for exciting DHARD, but we need to test amplitudes, phases and gains for this.  The current version of the script does its job although it is painfully slow, and is checked into the svn under asc/h1/scripts  THe resulting phases are in the attached screenshot. 

We saw that the instability in CHARD pit was becasue somehow the LP9 got turned on again, this is now off and CHARD seems fine.  

We tried powering up, were fine at 10 Watts.  We had an instability in PRC1 and PRC2 yaw at 13 Watts.  I reduced the Q on the complex zeros at 1.1 Hz for PRC2Y, which gives us slightly better phase and gain near the point where we seem to be unstable. Attached is a screenshot of the OLG measured with white noise at both 2 Watts and 10Watts, we might need to do a swept sign to get a good measurement around 1 Hz. 

After about 10 minutes at 12 Watts, we had the usual fluctuations in the recycling gain.  So the high bandwidth PRC2 loops haven't totally solved the problem. 

For the record, these are angle settings that give approximately good CO2 powers tonight, and the powers to aim for from Kiwamu's note:

We have twice had the rotation stage for CO2 Y go to an angle that was wrong by a lot (sending a few watts to the test mass for a few seconds).

I'm leaving the IFO locked at 10Watts.