Jeff K, Darkhan T,
Overview
CAL-CS synchronized oscillator settings for cal. line coherence calculations were lost after the recent power glitch (LHO alog 29592). The settings were lost because after populating the settings (see LHO alog 28995) on August 10, not all of the channels were monitored by SDF_OVERVIEW.
Today we restored the coherence calculation settings and accepted the changes in SDF_OVERVIEW.
Details
The power glitch did not cause losses of the H1CALCS filters, so running set_coherence_h1.py (that populates filter modules) was not necessary this time (only changes names of the "1/f^2" filters to ":1,1", same as in PCAL models).
However filter module switches needed to be turned on (those previously weren't monitored by SDF_OVERIVEW). Some of the synchronized oscillator settings were also lost during the power glitch, they have been fixed now.
Today we updated coherence calculation settings for the following lines:
35.9 Hz - ESD, SUS_LINE1 36.7 Hz - PCALY_LINE1 37.3 Hz - DARM_LINE1 331.9 Hz - PCALY_LINE21083.7 Hz - PCALY_LINE3
All channels have been added to the list of monitored channels and the values have been accepted in SDF_OVERVIEW tables (safe.snap and OBSERVE.snap).
Note: IFO was not locked when the screenshots were taken.
Terra, Dave:
new h1susprocpi model was installed. This adds 64x2k chans to the science frame. The 'place holder' zeroed data were removed at the same time. DAQ was restarted.
These 64 channels we're now saving are the BP_IN1 and DAMP_OUT of each mode in the damping scheme, so essentially the pre-damping loop downconverted error signal and the post-damping loop pre-upconverted drive signal.
related to 29648,
The output from HWSY doesn't look reasonable. This is something we knew, but this time a surprising thing was that, if I interpret the data as it is, the self heating on ITMY introduced negative lensing rather than positive lensing. This does not make sense. See the second attachment below. The first attachment is the HWS signal for ITMX with its prediction from the TCS simulator for comparison.
State of H1: has locked and made it to DC readout
Activities:
Relocking:
Jeff K, Chris Whittle
Following on aLOG 28363 (initial proposal) and 29250 (installation), we measured the open loop gain of the IMC loop (without full CARM) with the AG4395A, both with and without the daughter board 200 kHz pole. The GPIB is still connected to the AG4395A by the Common Mode Board.
TFAG4395A_15-09-2016_140247.txt has the transfer function without the daughter board, TFAG4395A_15-09-2016_140553.txt with the daughter board. The attached plots were generated with daughter_tf_plots.py.
See the attached plots of open loop gain, loop suppression and closed loop gain. Takeaways:
Also note some variation in the OLG at about 200 kHz compared to the previous measurement.
J. Kissel I've now measured the CARM Open Loop Gain Transfer Function in the two different states of the IMC PDH common mode board's new 200 kHz pole daughter board. As expected from above, the CARM loop is barely affected by the 200 kHz response change. (Also note that the daughter board can be turned on and off at will without affecting a 2W DC READOUT lock.) As such, I have left the 200 kHz pole enabled, and accepted H1:IMC-REFL_SERVO_FASTOPT as "On" in the down.snap of CS ECAT PLC2 beckhoff SDF system such that it sticks after reboots (there are no safe or OBSERVE.snaps for this SDF system). Attached are the results of the measurement. TFAG4395A_15-09-2016_191957.txt is the open loop gain with the daughter board ENABLED. TFAG4395A_15-09-2016_191352.txt is the open loop gain with the daughter board DISABLED. Summarizing the attached plots in words: the CARM loop has a UGF of 15 kHz, with a phase margin of 40 [deg] and very tolerable amount of gain peaking at about a factor of 2 at 20 kHz, all regardless of the configuration of this switchable pole in the IMC PDH common mode board.
Added 200mL to the crystal chiller.
FAMIS#6488
State of H1: unlocked, maintenance activities
Activities:
As of 20:29UTC:
Commissining Work: LSC and ISS
Daniel, Keita, Dave:
we installed new versions of h1psliss and h1lsc. This required a DAQ restart.
A brief history of IP10, the controller for IP10 had A channel go somewhat bad on 9/3/2016, controller was set to output 5k volts but its output was only able to do about 2k, then we had a power glitch on 9/10/2016, that caused the current output to go down and the pressure to go up (see attached graph).
Since IP12 is currently valved out, where the pump is pumping on a small volume, we decided to swap controllers between pumps. So for now IP12 will show some alarm values until the controller is fixed. And to keep the small volume at IP12 good, we are pumping with one channel despite of what the signal says.
The factory flanged flange containing the inadequate fasteners was "gappy" enough that I tried the easy in-situ replacement of its fasteners but unfortunately it didn't work (2x10-8 torr*L/sec leak) and I had to vent the RGA volume and replace the gasket along with adding the good fasteners -> pumped down RGA volume and leak tested new joint -> No leak detected (Leak Detector baseline signal 3.5 x 10-9 torr*L/sec helium). I didn't have the RGA laptop so I'll need to go out again at the next interferometer (IFO) downtime to verify the the RGA works after having being withdrawn from and reinserted into its protective nipple (this exercise can result in a grounding of some of the tight clearance electrodes upon re-insertion). Leaving work area shut down, i.e. there are no pumps running or related electronics energized etc.
I have increased the chilled water set point by 5 degrees F to 45 F on the corner station chiller.
After tweaking the alignment into the pre-modecleaner, I measured the power noise spectra
for both photodiodes PDA and PDB when either was used as the in-the-loop sensor.
The plot PDA.png is for when PDA was used as the in-the-loop sensor. PDB.png is for when
PDB is used as the in-the-loop sensor. When the ISS is off, in both cases the free-running
power noise measurements agree quite well. However the in-the-loop and out-of-the-loop spectra
disagree quite badly when PDB is used as the in-the-loop sensor. The in-the-loop noise suggests
there's enough gain in the loop in this case with the level being ~1.0E-8. The out-of-the-loop
spectrum is more than a factor of 10 higher, which suggests there's a difference in the two optical
paths (most likely beam pointing).
Not sure why at this stage. I would probably use PDA as the photodiode to be used as the
loop sensor (for now).
The BRS at EY has had a long term drift requiring periodic recentering. That drift seems to have stopped or changed sign, following the power outage on Saturday. Attached image is a 60 day trend for H1:ISI-GND_BRS_ETMY_DRIFTMON. The black streaks are from when the BRS went out of range and when it was recentered during Krishna's last visit. The little blip up to zero at the end is from the power outage, before the commissioners recovered the BRS code. Second image is the last 6 days, outage is when the signal goes to zero. Definitely looks like the drift has changed sign.
I checked the temperature ('H1:ISI-GND_BRS_ETMY_TEMPR') and it looks a bit lower than normal, so it doesn't account for the change in the drift. It may be good to go to EndY and check on the Ion pump controller and make sure that it is ON? If it didn't get turned on after the power outage, a rising pressure might be the cause for the change in drift. The Ion pump controller should have a High Voltage indicator which should be on and clicking the OK button should give you the pump current and pressure reading.
The ion pump was off. It took a couple tries to get it to come back on. Voltage was around 5200V and 9-12 mA when I left the end station, pressure was already back to ~1E-5 torr. The power supply is kind of hidden under some other stuff, under the beam tube. Gerardo tells me that the power supplies at each end station are different, the one at EX comes back on it's own, EY doesn't. I'll see about adding a note to the start up procedure in T1600103.
IP power supply status should be added to vacuum GUI in CDS so we can catch power failures right away.
Dave, Patrick Restarted all web medm screenshots on script0.
And all other driver dofs are quiet as well. Remember, Monday night 29667, this channel, H1:ISI-BS_BIO_IN_CD_ST1_V3_STATUS, was dropping to zero, indicating a thermal problem. Checks suggested the coil driver was not actually sending the bad signal and the BIO Chassis was responding appropriately to simulated state changes. The I/O computer cards were reseated and by default, all the machines were power cycled. Maybe we've seen the last of this issue for the time.
Sheila, Matt, Lisa The ISS has been oscillating a couple of times when reaching 50W in the last two locks. Sheila fixed that by turning off the AC coupling. We leave the IFO locked at 50W with the ISS AC coupling off, at Sep 15, 9.45UTC. It has been locked for about 20 minutes, powers are stable, no PIs. Matt updated SDF with the latest PI settings. We just noted that the PSL NOISE EATER is oscillating -- so please fix that in the morning.
The 50 W lock lasted for about 3 hours. It is unclear what broke it. There were two PI modes (modes 10 and 26) which rung and weren't successfully damped. See the attached.
It's possible MODE 26 broke the lock, although lockloss occured when the amplitude of the mode was much lower than the usual breaking point. We're still re-finding settings after the ETMY ring heater change that happened yesterday afternoon and probably the gain sign was wrong on this mode.
More interesting is the unusual broad noise between 14kHz and 16kHz seen the entire lock. In spectra below, orange is OMC trans showing high frequency behavior during last nights lock and a reference 'normal' lock from a few hours prior. Despite the suspicious frequency range, we don't think this noise is associated with PI (we've checked to make sure we weren't injecting, had wrong settings, etc.); even very high amplitude PI create a symmetric peak with much higher Q. Perhaps laser noise?
Below left is just after locking last night (note the cursor is sitting ~15410 Hz, an area where there's no known mechanical modes). Below right is ~5 seconds before the lockloss 3 hours later. PIs are ringing up in the latter, but amplitudes are below those that have broken locks in the past.

Below is a 'normal' spectrum from a lock earlier in the day while two PIs were ringing up to similar amplitdue.
