TITLE: 04/14 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 68Mpc
INCOMING OPERATOR: Jeff
SHIFT SUMMARY:
LOG:
Quiet shift, lock just rolled over 20 hours and nothing much is happening.
TITLE: 04/14 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 69Mpc
INCOMING OPERATOR: Jim
SHIFT SUMMARY: Locked for the entire shift and 12.5 hours total. No issues.
LOG: None.
Locked for 8.5 hours. Nothing to report.
While LLO was down:
1) We shook the input beam tube at low frequencies: no significant coupling below 8 Hz was found.
2) Tapped on top of a lot of chambers to see if falling metal oxide dust might produce fast transients like blip glitches: some transients were produced, more analysis to come.
3) We shook ISCT1 at 12.5 Hz (about the sway resonance of the table) and injected at an amplitude that produced clear scattering harmonic peaks in the 200 Hz region (consistent with motion amplitude of about 1 micron). This required about 40 times background velocity (see plot). We found dumped beams that were bight in the viewer and blocked them with black glass while watching the scattering peaks. The scattering harmonics seemed to mostly go away when we blocked a particular beam hitting one of the razor blade dumps (see figure). The razor blade dump seems to dominate the scattering and may not be quite good enough. We should replace it with a black glass dump with the reflected beam dumped on a razor blade dump.
Robert, Jenne, Vaishali, Heather
From 0:04:30-0:05:30 UTC, a Ducati motorcycle could be heard pulling out from the beam tube enclosure section near the control room. As a reminder to all motorcyclists on site, according to the list of NOT Acceptable activities in T1500425, while we are in Observing there should be "no running motorcycle engines closer than the Staging Building."
Mine was in the garage all day....so wasn't me.
Mea culpa. Thx Travis, and good discrimination in L. Twin vs. Inline 4.
TITLE: 04/13 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: Jeff
CURRENT ENVIRONMENT:
Wind: 26mph Gusts, 21mph 5min avg
Primary useism: 0.07 μm/s
Secondary useism: 0.14 μm/s
QUICK SUMMARY: Robert, Jenne, et al. doing some commissioning work in LVEA HAM 1 enclosure. LLO is finally back up and commissioners have been notified to wrap up their work. No issues regarding the IFO were handed off.
23:18 Jenne, Heather, Robert, and Vaishali out of the LVEA
23:19 Back to Observing
At the request of Rick and Sudarshan, the HIGH_FREQ_LINES Guardian node will start at 5751.3Hz and then decrease by 500hz every 24 hours after a lock loss. Currently the end is set to be at 1000hz, but it sounds like it will most likely be stopped manually before then.
Lower limit is now set to 2000Hz instead of 1000hz.
Committed the following files to the SVN repository /opt/rtcds/userapps/trunk/sus/h1/burtfiles/h1susprocpi_safe.snap /opt/rtcds/userapps/trunk/psl/h1/burtfiles/fss/h1pslfss_safe.snap /opt/rtcds/userapps/trunk/sus/h1/burtfiles/h1susitmy_observe.snap /opt/rtcds/userapps/trunk/sus/h1/burtfiles/h1susitmx_observe.snap /opt/rtcds/userapps/trunk/sus/h1/burtfiles/h1susprocpi_safe.snap /opt/rtcds/userapps/trunk/psl/h1/burtfiles/fss/h1pslfss_safe.snap /opt/rtcds/userapps/trunk/cal/h1/burtfiles/h1calcs_OBSERVE.snap
The attached image shows the condensate that has accumulated in our VBOD Main Turbo's exhaust after several years and many bake loads. This is a maglev turbo that has only been backed by scroll pumps and that has only pumped Class-A prepped parts.
Dropping the intent bit to commissioning so Robert can work on the list below. I just spoke with LLO and they are still working their issues. Will keep in contact with LLO Ops on status. Commissioning Activities: 1). Shake input arm below 8 Hz 2). Bang on HAM6 to make sure dust doesn’t produce blip glitches 3). Look into mitigating scattering on ISCT1 so we can use POP AIR
Optical lever trends: ITMY SUM has dropped from around 40K to less than 20K.
Commissioning and relocking this morning, while LLO is down. Environmental has been troubling, with high and gusty winds and a couple of small earthquakes. The primary microseism is elevated with the wind. Ran A2L repair script due to YAW coherence up to 0.9. After clearing SDF Diffs for PSL-FSS_COMMON_GAIN and IMC-REFL_SERVO_IN1GAIN went back to Observing while commissioners are resetting for the afternoon.
Everything looks fine here.
If you happen to be on one of the Debian machines, I've been working on the Python scripts for this task. They can be launched from the bottom two buttons (BSC CPS Python & HAM CPS Python) on the OPS>>WEEKLIES screen. They now plot properly calibrated spectra for the CPS with sensor noise specs and save images of the spectra directly to your Desktop folder. The script also looks at the high frequency ASD average (over 80-120 hz) and will say on the xterm window which sensors (if any) are "out of spec". Sadly, these scripts won't work on the Ubuntu machines, because their scipy.signal libraries are too old and don't include welch. Maybe if operators find this workflow easier (push 2 buttons, look at plots, check xterm, and attach images to alog, done) we can convince Hugh to change the FAMIS task.
Per Keita: Spoke with Brian O’Rielly. LLO will be down for an unknown period. LLO ops will contact LHO ops when they are about an hour from relocking. Robert will be doing commissioning work until 13:00. The intent bit has been changed to Commissioning.
These are the commissioning tasks Robert will be working on: 1) Look into mitigating scattering on ISCT1 so we can use POP AIR 2) Bang on HAM6 to make sure dust doesn’t produce blip glitches 3) Put heat source under beam path on PSL to test jitter from air path 4) Shake input arm below 8 Hz 5) Probably for a later date: laser vibrometer on swiss cheese baffle
[Vaishali, JimW, Jenne]
During maintenance, while no one needed the IMC, we tried out our new L2A decoupling filter for MC2. Recall that Jim found that it would be helpful in alog 35330, and we measured and fit TFs for it in alog 35397.
We found that (a) the pre-existing L2A decoupling was in fact worse than doing nothing at all, and (b) that our new filter works well.
In the attached screenshot, the upper left corner is the Foton Bode plot of our decoupling filter. In the other 3 DTT panels we have the coherence and transfer functions of 3 different MC2 L2A configurations. For these measurements, the IMC was unlocked, but MC2 still aligned. The red traces in all panels are with no L2A decoupling at all. The blue traces are with the old L2A "decoupling" gain. That was a flat gain, and clearly was making things worse than doing nothing at all, over a pretty broad frequency range. The green traces are with our new L2A decoupling filter on, and we win almost 20dB of isolation below a few hundred mHz.
We have accepted the new L2A settings for MC2 in the safe and observe SDF files, so they should always be on now.
I've looked at the coherence between MC2 M1 length drive and the two pitch witnesses (MC2 Trans qpd and MC2 M1 Pit) during locks before and after the install of the new L2P feedforward, and things look better. Attached plot shows the coherence between MC2 M1 L and MC2Trans (top plot, blue is before, red after) and MC2 M1 L and MC2 M1 P (bottom plot, blue is before, red after). Below .1 hz the coherence is much better, which should help for wind and earthquakes, which is what I was looking at originally anyways. Above .1hz the coherence is pretty much unchanged, not sure why, maybe the motion is dominated by the table motion at those frequencies?
Always useful to actually post promised plots...
Beam position based on exciting the pitch(yaw) DOF and then changing P2L(Y2L) gain to minimize the peak. Both measurements use a sign convention that is consistent with UR coil values. The Dec 2013 alpha numbers are as posted, however the beam distance numbers have been recalculated. In Dec 2013 the conversion from alpha to mm was 37.5mm/alpha, and the current conversion is 42.2mm/alpha.
| 13 Dec 2013 | 21 Mar 2017 | change | |||
| alpha | beam distance from center, mm | alpha | beam distance from center, mm | mm | |
| MC1 pitch | -0.043 | +1.81 | -0.057 | +2.42 | +0.6 |
| MC1 yaw | +0.029 | +1.22 | +0.089 | +3.76 | +2.5 |
| MC2 pitch | -0.062 | +2.62 | -0.183 | +7.72 | +5.1 |
| MC2 yaw | -0.048 | -2.03 | -0.020 | -0.084 | +1.2 |
| MC3 pitch | +0.041 | -1.73 | -0.051 | +2.15 | +3.9 |
| MC3 yaw | -0.052 | -2.19 | -0.135 | -5.70 | -3.5 |
The animation that's attached shows the ideal IMC alignment in a dashed magenta line, the Dec 2013 alignment in red, and the Mar 2017 alignment in blue. Green markers show the optics, squares are MC1, triangles are MC2, and circles are MC3.
The lines and markers accurately represent the optics and the beam changes, but are not to scale. I altered some numbers to make the changes visible in this animation.
| 13 Dec 2013 | 21 Mar 2017 | change | |||
| alpha | beam distance from center, mm | alpha | beam distance from center, mm | mm | |
| MC2 yaw | -0.048 | -2.03 | -0.020 |
-0.84 |
+1.2 |
