3:15pm local time Took 1:07 min. to overfill CP3 - half turn open on LLCV bypass valve with bypass exhaust valve open. Next fill due within 72 hours (by Thursday) before 4pm local.
Turbo controller left energized until tomorrow.
First plot shows the last IMC locks before the PSL work started, and the alignment of the IMs.
Second plot shows the our first IMC lock since PSL work started, and the change in the IMs alignment (IM2 pitch, the worst offender).
TJ kindly agreed to restore the pre-PSL work alignment of the IMs, and since we don't have light, we'll need to check IM4 Trans QPD with the next IMC lock.
I managed to get them back to their previous values, but there were a few that I seem to drift on their own. IM3 P was the worst culprit, and I'm guessing this is normal since its slider value is 57700.
Ross, Tega, Terra, Ed Daw
We have updated the h1susetmxpi model to include a linetracking filter (iwave) in order to more accurately track parametric instabilities. The filter is placed between the bandpass and damping filters in each PI mode. The basic idea of iwave is that it is a resonant filter that runs with a phase lock loop. The loop tracks changes in frequency and amplitude of the signal that it is closest to in frequency and adjusts the filter to resonate at the tracked frequency. Two parameters should be set before the line tracker is implemented, the starting frequency and tau. The starting frequency should be set to the closest known line frequency of the signal you want to track. The tau parameter sets the response time of the filter but also the bandwidth. For higher Q signals it is best to use a longer tau parameter. We have also included a phase offset to the model for the linetracker which can be tuned to ensure the ESD is damping the PI with the correct phase. The medm screens mentioned in Terra's alog have been updated to include this filter.
The SUS_CUST_PI_MODE screen should now have a link to the top screen for iwave where tau can be changed and displays a strip chart of the error signal (black), input signal (blue) and frequency tracking (red). The error signal can be used to determine how well the signal is being tracked i.e. it should get smaller as the signal is being more accurately tracked. This screen also has a link to the actual iwave filter screen where the starting frequency can be changed and output monitors including ones for frequncy and amplitude are displayed. The reset button in the filter can be used to reinitialise the filter with the selected tau and starting frequency. A bypass switch is included to allow data to be unchanged when passing through the filter if necessary. We have also updated the mode screen so that the QPD monitors are now looking at epics outputs in the h1etmxpi model rather than the filtered outputs.
We will hopefully begin testing this method of damping in comparison to just using the bandpass filters soon. This will be done by turning off the ring heater, waiting for the signal to ring up and then applying the damping signal to the ESD. We will need a 15W or higher laser power in order to ring up the 15440 Hz mode which has been seen previously.
Kyle, Chandra Verified HAM6 IP was operating and then valved it back into HAM6 chamber at 9e-7 Torr this morning. Immediately valved out turbo pump and will monitor IP and pressure throughout the day to make sure load is not too high for IP supply. Turbo is still ON and ready to be valved back in if need be.
IP supply survived with no turbo help. We will now turn off turbo station.
SEI - Fiddling with the BRS
SUS - All good
PSL - Water flow sensor issue over the weekend. Should be back after the sensor is replaced. ISS investigation.
Vac - Ready to turn on the ion pump. Change the actuator on CP-1. Mid station Beckhoff switch maybe as soon as today.
Fac = Beam tube enclosure sealing on both arms.
There will be no internet from 9-11 NEXT Tuesday. (WP5831)
TITLE: 04/18 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
Wind: 4mph Gusts, 2mph 5min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.25 μm/s
QUICK SUMMARY: The PSL had some issues over the weekend so it seems like that will be worked on today. Many SEI WDs are tripped and a few SUSs.
Attached are plots of the pre-modecleaner, power stabilisation and frequency stabilisation servo
transfer functions as they were on Friday.
I'm not sure what the dip at ~23kHz in the frequency stabilisation plot is but it might be
due to injection locking of the high power oscillator.
The power stabilisation servo needs adjusting. At the moment the displayed diffraction
levels are too high - it needs to be recalibrated.
The pre-modecleaner servo is functional but also needs checking out. Even with attenuating
the light on the locking photodiode, its output bursts into oscillation every now and then which
causes the pre-modecleaner to "blink".
I got some alignment work done, but not as much as I would have liked.
I had just finished aligning the Xarm to green, although it's flashing and not locking. Flashes up to 0.8, so it seems fine, but the PLL is complaining about not enough beatnote signal. I don't actually know where that PD is, so I can't check it's alignment.
The IR flashes also looked good, so I was getting ready to misalign the ITMY, use BS to get the beam onto AS_C, and then work on aligning ISCT6. However, the PSL decided that it had had enough, and decided to turn off. So. I'll come back to this Monday after the laser crew is done with their activities for the day.
Side note: The Yarm green is complaining about beckhoff communications errors, if someone more knowledgeable than me could have a look at that Monday as well.
The PSL has turned itself off.
I spoke with Jason, and it looks like perhaps the chiller decided to turn off, which triggered the laser interlock to shut off the PSL. The crystal chiller reservoir looked fine, although there was water on the floor and a cap had popped off (apparently this happens as part of the chiller turn-off?).
The H1:PSL-OSC_BOXHUM channel has been exponentially increasing over the last ~20 hours from 28 to 35, which is consistent with the air conditioners being turned off around that time. Jason tells me that when the AC isn't drying things out, the box humidity usually sits in the 35-45 range, so since it's just now getting to 35, it seems like there is NOT a water leak.
Jason logged in remotely, and agrees that things should be safe to leave as-is until he and Peter come in on Monday morning.
Attached is a plot of the power measured at the base of the IO periscope as a function
of the requested angle in the MEDM screen.
The following angles may be of interest:
minimum power -25 degrees
maximum power -70 degrees and 20 degrees
Measurements were performed with the Ophir power meter, using 3 second averages.
The requested angle was consistent with the scale etched on the rotation stage.
To check that the half waveplate was not slipping within its mount, angular requests
moving the waveplate from one end to the other were made and the power measurements
were consistent with previous measured values. So there was no experimental evidence
of the waveplate slipping within its mount.
Jason, Peter
After experiencing some problems locking the frequency stabilisation servo yesterday. The plan was to improve the mode matching to the pre-modecleaner. After which the frequency stabilisation servo still did not lock. The cause was traced to the locking photodiode not having it's power cord plugged in. The power cord, located underneath PSL Rack 1, must have been disturbed. Once plugged in again, the frequency stabilisation servo locked. The power incident to the pre-modecleaner was increased to ~150 W. The measured throughput of the pre-modecleaner was ~124 W, with the power stabilisation off. With the power stabilisation the throughput was ~117 W. The power stabilisation suffers from occasional glitches. It is not known where the glitches come from, they may well come from either the pre-modecleaner or the oscillator. The output power of the pre-modecleaner was attenuated before the IO electro-optic modulator to 60W. The maximum power available at the base of the IO periscope is ~60 W. The so-called "volume" control was tested, and a maximum power of 56 W was measured when the rotation stage MEDM screen was used to request a power or angle. We found that both the requested angle and requested power are consistent with the rotation stage scale and the power meter. A more detailed report will be submitted later. Jason, Peter
All time in UTC
Log:
23:24 Lase CO2 laser to make power measurement.
00:12 CO2 laser turned off. The rotation stages' angles are set such that they output lowest power the next time the lasers are lased. The "Go to minimum" function doesn't seem to work very well with CO2X (it gave 0.9 W output) so I manually set it to go to 40 deg (0.015 W output).
00:41 Resetting WDs.
01:18 Peter and Jason came out. We have the light!
02:45 Keita transitioned LVEA to LASER HAZARD
03:01 Jenne to help Keita at ISCT6
Possible issue with in-vac alignment. Shop closed early.
We also realigned all the main optics.
We're able to see the beam on ISCT6 camera but in-vac alignment is somewhat questionable. We'll align the table once at least the green transmission is seen in ISCT1.
The table fan was turned on and then off.
Accelerometer on HAM6 door is not connected.
The gain of the H1ALS-C-SHG_IR/GR_DC photodiodes needed to be reduced to 20dB each. Comparing the power reading to 14 days ago, we get
| Photodetector | Before | Now | Unit | Scaling |
| H1:ALS-C-SHG_IR_DC | 18 | 54 | mW | 3.0 |
| H1:ALS-C_SHG_GR_DC | 0.13 | 1.0 | mW | 7.7 |
| H1:ALS-C_SHG_GR_DC @32.5C | 1.1 | mW | 8.5 |
SHG temperature started out as 33.5C and was reduced to 32.5C to optmize the new green power.
Miriam, Jenne *SUMMARY* We check the L1 and L2 FASTIMON channels introduced in Feb 2016 and the L3 LVESDAMON at the times of blip glitches (found on data from Feb 11 and Feb 13). This investigation suggests that the actuation electronics are not the cause of blip glitches, but their origin must be in the interferometer. *DETAILS* We investigate 5 different times: 1139199176.774658, 1139240197.712158, 1139246246.086670, 1139400338.701172, 1139412012.846924 The channels we look into are of the kind H1:SUS-(E/I)TM(X/Y)_L(1/2)_FASTIMON_(UL/UR/LL/LR)_OUT_DQ and H1:SUS-ETM(X/Y)_L3_LVESDAMON_(UL/UR/LL/LR)_OUT_DQ. These channels show the actuation on the mirrors. We plot the whitened data from the H1:OMC_DCPD_A_OUT_DQ as well as the whitened data from the channels mentioned above. The vertical lines show the times listed above. In the attachment we show only the channels that showed something significant. When the blip glitches are loud (higher SNR), it can be observed in the plots that the actuation starts pushing on the mirrors only after the DCPD has seen the blip glitch. Therefore, the blip glitch must have originated in the interferometer and not in the actuation electronics.
