The shaft seal is leaking on the Y-end chilled water booster pump.  This pump "boosts" the chilled water pressure to make up for transmission losses.  I valved-out the parallel chilled water circuit which contains this booster pump and which supplies the Mechanical Room and VEA.  The HVAC should not be affected.  The pump has been removed and will be repaired or replaced asap. 

Today, while doing some cabling for PSL Picomotors, I noticed that the clamping of hte PZT actuator doesn't look right (see attached photos).

It seems that the screws that apply the clamping force, thus constraining the PZT body between the upper vee and the lower vee (and compressing the viton damping cylinder in the process) were not sufficiently tightened.

The PZT actuator cylinder appears to be floating on top of the viton cylinder, lightly constrained by the upper vee, but not the lower one - there is an obvious 1-2 mm gap between the PZT cylinder and the lower vee, on both sides.

To aid the diagnosis of RF whistles (aka arches), I tried a matlab script that LLO has been using. It essentially just makes normalized spectrograms of channels that are good witnesses of the whistles. The attached plots are the outputs from running this script on data from last night's lock, around 10:00:00 UTC. The whistles/arches are clearly visible in the OMC PI (parametric instability) readout channel up to 32 kHz; they're also quite visible in IMC_F and PRCL (8 kHz and below). At this time the IMC VCO frequency was between 78.781 MHz and 78.794 MHz.

The script is 'look_for_arches.m', and is in:  /ligo/home/peter.fritschel/Whistles/

Filiberto, Ed, Richard, Rich A

ETM-X ESD drive system has been floated from any connection to ground.  After establishing that the whole system is floating WRT rack or building ground, we made a single connection to the beam tube as a reference point (see attached PDF diagram)

Summary of Actions:
I. For cable HI-SUS-ETMX-90 cut pin 8 (and unused pin is by accident) to remove a ground
in the D1100809 AA Chassis Interface Board (CH I to 6) input connection. The actual cut was made in the gender changer on the front panel D 15 monitor output of the HV AMP. This cable is the HV monitor read back for the HV Amplifier Box.
2. Removed all rack ground connections in remote DC power supplies.  The returns of all the DC outputs were previously connected to the rack/building ground
3. Connected the HV Amp & LV AMP to beam tube ground next to ESD rack.  This is the single ground point for the ESD system
4. Installed dielectric breaks between rack and HV ESD amps
5. Verified entire ESD system is floating, then deliberately grounded to beam tube
6. Lifted cable shield connection on cable H1-SUS-ESD-5 at the LV Driver PI input connector (D-I 5)
7. Lifted cable shield connection on cable H1-SUS-ESD-6 at AA input (LV Driver monitors D-9)
8. Restored ground voltage mon (PEM) between beam tube & top of LV ESD Amp
9. Transitioned back to permanent ESD DC supplies in remote DC racks
10. Swapped HV preamp back to the one that was originally installed in EX so the 3RD IFO unit can be
returned to the H2 building

WP8108 DAQ 10GE switch reconfigure

Jonathan, Dave:

Please see alog below for details. DAQ computers were restarted twice during this upgrade. The DAQ was not reconfigured.

WP8038 h1guardian1 machine relocation

Jonathan, T.J., Dave:

the new V4 h1guardian1 machine was moved from its temporary location to its correct location. The V2 machine (old guardian) which was in this slot will get racked as h1dmt4 once we get a compatible rail kit installed.

TJ monitored the restart of the guardian nodes, there were no issues.

WP8075 DMT test machine upgrade

Jonathan, Greg, Dave:

h1dmt2 was moved from its current location to below the h1dmt0,1 stack (a slot vacated by the h1guardian1 move). This in turn frees the space for the new h1dmt4 machine.

cdsfs1 reboot

Carlos, Jonathan:

Carlos discovered issues with cdsfs1. It was updated and rebooted.

Beckhoff restarts and SDF restart.

Daniel, Dave:

Daniel restarted some Beckhoff systems and found that the SDF for C1PLC1 became unresponsive. I restarted h1sysecatc1plc1sdf to fix this.

P. King, R. Savage, J. Oberling, D. Sigg

FSS RefCav Picomotor Mirror Mounts

At the request of the LHO commissioning team, today we installed 2 picomotor equipped mounts in the FSS RefCav path.  We replaced the mount for mirror M27 (immediately after the FSS EOM, 1st attachment) and for the upper periscope mirror (UPM, 2nd attachment).  We used M27 instead of the lower periscope mirror (LPM) because the LPM is too close to the RefCav; with this setup, M27 primarily changes beam position while the UPM primarily changes beam angle.  The 3rd attachment shows both new picomotor mounts.

The same driver (PICO D) that runs the picomotors for the PMC input mirrors (mirrors M06 and M07) had 2 empty channels, so we used these for the new RefCav picomotors.  As of now, channels 1 & 2 are for the PMC picomotor mirrors and channels 3 & 4 are for the RefCav; Daniel changed the displayed channel names on the picomotor control MEDM screen to reflect this.  To end, we confirmed that all picomotors functioned as expected, which they did.  When we left the enclosure the FSS RefCav TPD read ~4.1V, and the PMC was transmitting ~54.5W.  During the next maintenance window where we do not have an enclosure incursion, I will tweak the alignment into both the PMC and RefCav.

70W Amplifier Power Monitor PD

We had noticed some odd behavior with the 70W amp power monitor PD (the PD that the 70W amp power watchdog triggers off of).  When blocked directly at the PD aperture, the PSL Beckhoff software reports ~3W on this PD; when blocked farther away the reading is ~52W.  We suspected the cause to be room lights, so we added a tube with a RG850 (808nm pump light filter) screwed onto the end (4th attachment); this second RG850 was added to block more of the room light, as one wasn't quite enough.  This reduced the blocked reading to ~3W regardless of how far away the blockage occurred, with no degradation in the amount of power read by the PD when unblocked.

The DMT computers have been patched and rebooted, bringing in gds2.18.16-1.el7 and " new features needed to connect idq to the low latency frames," as per WP 8106. John Zweizig will be reconfiguring the new features.

WP8108

Jonathan, Dave:

The DAQ Fujitsu 10gigabit switch was reconfigured today in preparation for a dual-data-concentrator upgrade.

In the old configuration, all ports belonged to VLAN-102, and there were some gaps in the port assignments.

In the new configuration, a new VLAN-110 was created and assigned to the first 6 ports. All old ports were shuffled to the right to clear these first 6 ports, and port gaps were filled. This required a data interruption for all DAQ machines except h1tw1.

We did the upgrade in two phases.

PHASE-I, assign and activate ports 7-16 to VLAN-102, move DAQ machines one-at-a-time to their new port, waiting for each one to come back before proceeding. h1dc0 was last to be moved, since its return caused all the other systems to restart again. From a user's point of view, this looked like two DAQ restarts (with no configuration change). Where necessary, ports 17-24 were assigned to the default VLAN-100 and disabled.

PHASE-II, disconnect the FE-DC0 link from direct Netgear-to-h1dc0 to Netgear-VLAN110-h1dc0. This was done in two steps to ensure h1dc0 continued to run throughout. First the fiber from the last Netgear port (50) was disconnected at h1dc0 and rerouted to port-1 of the Fujitsu. A new 2M fiber from port-3 Fujitsu (VLAN-110) took its place at h1dc0. While this was being routed about half the front end's data was bad. This was most of the corner station. Last step was to disconnect Netgear-port49 to h1dc0 and replace this with the second 2M fiber from Fujitsu-port-4.

Data went good again, no restarts of mx_stream or h1dc0 were needed.

Updated the corner TwinCAT code to the most recent SVN revision. This adds the names for the new picomotors installed in the PSL reference cavity path. Nothing else should have changed.

Tried getting the 2G TTFSS working.  In summary, it failed.

    More details to follow.

Nutsinee Daniel

With the discovery that the noise eater can add noise to the beat note between the PSL and SQZ lasers (LLO alog 43837), we added a 100MHz high pass filter to the spare TTFSS (S1700330).

On the PFD D1002471 we changed:

1. R1 was removed
2. F1 was stuffed with a Mini-Circuits PHP-100+

This unit was installed and the old unit removed (S1700331). We also removed the IQ demod version of the TTFSS that was still on top ISCT6.

Noticed that the fan of the laser power supply starting to sound like a coffee grinder...

J. Kissel, J. Oberling
Work Permit 8109
FRS Ticket 12394

Jason installed new components for SR3 optical lever this morning, which had died mid-February 2019 (LHO:47066). To check it's functionality, I've 
- Checked that the SUM is nice and high (good!)
- Checked its centering (good!), and
- Compared its amplitude spectral density in Pitch, Yaw, and SUM against PR3's optical lever -- a similar optical lever watching a similar suspension on a similar isolation system. (not yet good)

The noise above ~50 Hz is dominated by some white noise at the equivalent of ~1.5e-11 rad/rtHz, which I suspect is ADC noise. 
The straightforward solution is to just apply some analog whitening as has been done with all other levers. 
PR3's lever doesn't hit white noise until ~500 Hz, at the equivalent of 2e-12 in YAW; PIT is not limited by ADC noise, so we should be able to achieve this level of performance.

Once the whitening has been tuned, this test will need to be repeated, so I've stored the template for this measurement in 
    /ligo/home/jeffrey.kissel/Templates/DTT/
        H1_XR3_OpLev_Comparison.xml
for that future use.

Following up on 47176, Craig did a series of MICH noise injections at different times during the lock, to check if the MICH to DARM transfer function is changing. He switched off the MICHFF for each measurement, so what we measure is the entire MICH to DARM coupling (not the residual after feed-forward).

The suspicion was that the coupling changes during thermalization. This is confirmed. The plot below shows the measured coupling at different times, reported as minutes elapsed after powering up to 30 W.

Although at first inspection the four measurements seem quite similar, if we compute the ratio of each measurement over the first one (used as reference), we see that there are changes of the order of 4% in amplitude and 2.5 degrees in phase. This is most likely a limitation on the performance of the MICH feed-forward cancelation.

Averaging Mass Centering channels for 10 [sec] ...
2019-03-04 12:04:49.360399
There are 10 T240 proof masses out of range ( > 0.3 [V] )!
ETMX T240 1 DOF X/U = 0.412 [V]
ETMX T240 1 DOF Y/V = 0.317 [V]
ETMX T240 1 DOF Z/W = 0.419 [V]
ETMX T240 2 DOF X/U = -0.307 [V]
ETMX T240 2 DOF Y/V = -0.736 [V]
ETMX T240 3 DOF X/U = 0.345 [V]
ITMX T240 1 DOF X/U = -0.427 [V]
ITMX T240 3 DOF X/U = -0.373 [V]
ITMY T240 3 DOF Z/W = -0.59 [V]
BS T240 1 DOF Z/W = 0.31 [V]

All other proof masses are within range ( < 0.3 [V] ):
ETMX T240 2 DOF Z/W = 0.234 [V]
ETMX T240 3 DOF Y/V = 0.292 [V]
ETMX T240 3 DOF Z/W = 0.292 [V]
ETMY T240 1 DOF X/U = 0.085 [V]
ETMY T240 1 DOF Y/V = 0.264 [V]
ETMY T240 1 DOF Z/W = 0.107 [V]
ETMY T240 2 DOF X/U = 0.107 [V]
ETMY T240 2 DOF Y/V = 0.021 [V]
ETMY T240 2 DOF Z/W = 0.036 [V]
ETMY T240 3 DOF X/U = 0.115 [V]
ETMY T240 3 DOF Y/V = 0.107 [V]
ETMY T240 3 DOF Z/W = 0.289 [V]
ITMX T240 1 DOF Y/V = 0.165 [V]
ITMX T240 1 DOF Z/W = 0.138 [V]
ITMX T240 2 DOF X/U = 0.184 [V]
ITMX T240 2 DOF Y/V = 0.165 [V]
ITMX T240 2 DOF Z/W = 0.257 [V]
ITMX T240 3 DOF Y/V = 0.152 [V]
ITMX T240 3 DOF Z/W = 0.057 [V]
ITMY T240 1 DOF X/U = 0.217 [V]
ITMY T240 1 DOF Y/V = 0.142 [V]
ITMY T240 1 DOF Z/W = 0.192 [V]
ITMY T240 2 DOF X/U = 0.154 [V]
ITMY T240 2 DOF Y/V = 0.268 [V]
ITMY T240 2 DOF Z/W = 0.24 [V]
ITMY T240 3 DOF X/U = -0.092 [V]
ITMY T240 3 DOF Y/V = 0.23 [V]
BS T240 1 DOF X/U = 0.004 [V]
BS T240 1 DOF Y/V = -0.078 [V]
BS T240 2 DOF X/U = 0.079 [V]
BS T240 2 DOF Y/V = 0.29 [V]
BS T240 2 DOF Z/W = -0.02 [V]
BS T240 3 DOF X/U = 0.112 [V]
BS T240 3 DOF Y/V = -0.162 [V]
BS T240 3 DOF Z/W = -0.154 [V]
Assessment complete.

Averaging Mass Centering channels for 10 [sec] ...
2019-03-04 12:07:07.353372
There are 1 STS proof masses out of range ( > 2.0 [V] )!
STS A DOF X/U = -7.969 [V]

All other proof masses are within range ( < 2.0 [V] ):
STS A DOF Y/V = -0.922 [V]
STS A DOF Z/W = -0.258 [V]
STS B DOF X/U = 0.29 [V]
STS B DOF Y/V = -0.523 [V]
STS B DOF Z/W = -0.308 [V]
STS C DOF X/U = 0.358 [V]
STS C DOF Y/V = 0.165 [V]
STS C DOF Z/W = 0.645 [V]
STS EX DOF X/U = 0.026 [V]
STS EX DOF Y/V = 0.345 [V]
STS EX DOF Z/W = 0.317 [V]
STS EY DOF X/U = 0.359 [V]
STS EY DOF Y/V = -0.13 [V]
STS EY DOF Z/W = 0.793 [V]
Assessment complete.

Here's another update to previous simulation of the effect of the optical path distortion (OPD) in ITMY due to the point absorber (following up on 47027 and 46952).

Simulation details:

• simulated the effect of the point absorber while moving it with respect to the beam center. I kept the same optical path distortion (OPD) amplitude, but moved the peak from the beam center (labelled 0 cm below) in steps of 1 cm, up to 5 cm from the beam center
• the effects of the intrinsic substrate lens, CO2 and RH are included, following 47060
• improved the IFO locking: now DARM, CARM, PRCL and MICH are locked using the simulated error signals. SRCL error signal is not good for the lock, there are multiple zero crossings, and none of them correspond to a place where the DARM transfer function looks like what it should be in broadband signal recycling configuration. So SRCL is kept at a nominal "zero" position which gives a reasonable DARM response

Results:

• moving the position of the point absorber has a large impact on the RIN to DARM coupling. The trend is not monotonic. The OPD caused by a point absorber at a few cm from the beam center seems enough to explain the measured RIN coupling.
  
• it looks like the change in the high frequency (>100Hz) RIN coupling depends strongly on the MICH locking point. The main effect of the OPD is to induce offsets in the MICH error signal. The plot below shows what happens when MICH is moved around the error signal zero, with the point absorber at 5cm. The DARM / RIN transfer function is computed at 1 kHz for reference. Clearly, the zero of the MICH error signal does not coincide with a minimum of RIN coupling. It's worth noting that moving MICH by a few nm around the error signal zero does not change much the DARM response. The bottom panel shows the I and Q of the MICH error signal. MICH is locked on POP RF45 Q.
  

Danny, Dan

9MHz RIN line over locks

We put a line at 70.123Hz in the 9MHz for a few locks to see how it was behaving over time. When it was one we had a few short locks and two longer ones so far. It seems there are two states in which the coupling finds itself, one that peaks around "8" and another "6". This may coincide with going to LOWNOISE_ESD_ETMX (Guardian state 514) - the jump up in RIN coupling for red/green/orange seems to happen at roughly the same time after we go up to state 514. During the two long locks it's clear there's some long time constant to the RIN coupling, it takes around 4000s after going to 30W for this to settle. So depending on the thermal state we took the RIN measurements previously this might be a reason we got confused.

ITMY Mask

Last night we tried out the ITMY mask. The initial plan was to just apply the mask with the IFO unlocked to see how the induced OPD compared to what we expected. Then as we had the IFO to ourselves we decided to just go for it and try it out in a full lock to see what happened. Edit: this test was just to get the CO2 mask on at the expected power without causing a lockloss, the expected implementation requires changing ring heaters as well which is something to try another day.

Initially the OPD doesn't look quite like we expected. What isn't obvious is the crescent moon like shape seen in alog 46976 (Top right figure). This could be because the HWS probe beam isn't illuminating the full area so we just see a small section of it. I took the 30W point absorber OPD and added it to the offline mask OPD to get a rough idea of what might be the total effect, from this it reduces the overall optical depth and the larger spatial frequency heating from the absorbers.

From initial inspection the alignment of the minimum is not too far off from the point absorbers, we might want to try shifting the mask slightly in future. However it looked reasonably well aligned enough to try in a full lock.

FLIR image of mask

We powered up to the 30W state but didn't go to low noise ASC. We then put the mask in and stepped up in CO2Y power 100mW, 200mw, 400mW in 1000s intervals. We compare this with the 30W lock we had yesterday with the 9MHz RIN line on where we also didn't go to a low noise state. Looking at the RIN coupling we can see an improvement as the mask is introduced, then when we switched it off it goes back to as it was before. I injected a line that was 10x larger than the previous day by accident so the amplitude is rescaled and the line is less noisy. In hindsight we should have left it on a bit longer to see how it affected the steady state after 4000s, however we wanted the thermal state to return to normal for the night shift commissioning. From the data it looks as if the RIN coupling levels off between 3000-4000s. It looks to be at roughly the same level as the steady state case without the mask. Perhaps there is another dominating coupling effect at that stage where the mask no longer helps.

RF90/RF18/PRG/HWS traces with and without the mask.

Comparing with and without the mask we can see:

• RF18 looks slightly higher, RF90 slightly lower
• PRG maybe a little lower
• ITMY spherical power drops 155uD to 148uD

Things to try next:

• Alignment of the mask. The mask OPD needs  ~-0.5cm in x to align it better with the point absorbers. Assuming the CO2 telescope images the mask with a magnification of 23 on to the compensation plate, that means we need to move the mask ~200um
• Could try adjusting CO2X or RH Y to change differential lensing and see if we see similar drops in RIN coupling, RF18, etc. Perhaps we just need to tune the current TCS actuators better.
• Try mask after 4000s and at nominal low noise to see if it actually improves the sensitivity and drops below the steady state RIN we see