TITLE: 08/30 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: TJ
SHIFT SUMMARY:  Down for maintenance, SRC Gouy phase measurements, and ISS work until ~21:00.  Ran through initial alignment and the IFO locked up to DC Readout easily.
LOG:

15:03 Karen to LVEA

15:09 Bubba getting 3IFO crates down from LVEA racks for Betsy

15:11 Ed to EY OPLEV work

15:22 Peter to PSL racks looking at connectors

15:29 Peter out

15:29 Gerardo to LY vac rack

15:33 Richard to HAM2

15:45 Kiwamu to LVEA for Gouy phase measurements

15:52 FIle to EY WFS readbacks

15:56 Chandra to LVEA

16:00 RIchard to LVEA

16:15 Hugh restarting HEPI pump station

16:23 Norco to MX N2

16:54 Gerardo done

16:58 Chris to EX

16:58 Hugh to ends for HEPI checks

17:04 Richard to LX vac rack

17:06 Robert to LVEA setting up injection equipment

17:08 Karen to EY

17:09 Kiwamu out

17:21 RIchard out

17:34 John and Chandra to LVEA

17:46 Hugh done

17:51 Jeff B to LVEA

18:00 Gerardo to LVEA

18:01 Jeff B done

18:13 Karen out of EY

18:16 Corey to squeezer bay

18:37 John and Chandra done

18:37 Gerardo done

18:40 Jenne to LVEA regluing seismos

18:40 Kiwamu done with SRC meas.

18:40 Keita to swap ISS board

18:44 Corey out

18:55 Jenne done

19:02 Robert to LVEA

19:41 Keita done

20:22 Gerardo done

20:22 Chandra done

20:24 Kiwamu and Corey to LVEA taking pics

20:50 Kiwamu and Corey out

21:10 ETMx RMS WD tripped

22:34 Sheila to LVEA

Elli (remotely), Kiwamu

Today, I spent a few hours to get an SRC gouy phase measurement done. I was able to finish a first round of measurement.

The data will be analyzed by Elli remotely.

[The set up]
The first attachment shows a simplified layout of ISCT6 for the measurement.

It seems that the set up have been almost unchanged except for CAM17 which seems to be further away from the beam splitter in front by a couple of inches (see previous setup in 25510). This shift  could be due to the re-alignment activity that Koji and I did 20 days ago (29030). We might have shifted the CAM17 position because it was in the way of the OMC reflection path. Nevertheless, the alignment of the beam onto CAM17 was already good from the beginning and I need a slight touch on a steering mirror to get the beam centered on CAM17.

Additionally, some more pictures are available at ResouceSpace.

[The measurement]
As opposed to the previous method, the method we tried today is an AC measurement or some kind of lock-in technique where we excite an optic (e.g. BS or PR2) at a non-zero frequency. Our hope is that it is going to get rid of undesired effects from slow drift of suspensions' alignment.

Laser power into IMC = 25 W

IFO configuration = single bounce with ITMY aligned (i.e. ITMX misaligned)

CO2Y = 287 mW

ITMY ring heater = 0.5 W (0.25 W for upper and lower segments each)

- The first measurement
 Started at 18:10:42 UTC (Aug/30/2016)
 Ended at 18:20:42 UTC (Aug/30/2016)

 Excitation to SUS-BS_M1_OPTICALIGN_Y_EXC
 Frequency 0.2 Hz
 Excitation amplitude 5 urad

- The second measurement
Started at 18:28:20 UTC (Aug/30/2016)
Ended at 18:38:20 UTC (Aug/30/2016)

Excitation to SUS-PR2_M1_OPTICALIGN_Y_EXC
Frequency 0.2 Hz
Excitation amplitude 20 urad
 

[Detailed settings]

I adjusted the exposure time so that none of the pixels saturate while keeping high intensity counts. This ended me up with an exposure time of 700 (usec, I believe) for ASAIR (CAM18). Doing the same adjustment, I set that of CAM17 to 1000 usec. Also the followings are the camera settings that I used.

-CAM18 setting
[Camera Settings]
Camera Name = H1 AS Air (h1cam18)
maxX = 659
maxY = 494
Exposure = 3000
Analog Gain = 100
Auto Exposure Minimum = 150
Name Overlay = True
Time Overlay = True
Calculation Overlay = True
Do Calculations = True
Auto Exposure = False
Calculation Noise Floor = 25
Snapshot Directory Path = /ligo/data/camera
Frame Type = Mono12
Number of Snapshots = 1
Archive Image Minute Interval = 0
Archive Image Directory = /ligo/data/camera/archive/

[No Reload Camera Settings]
Base Channel Name = H1:VID-CAM18
Camera IP = 10.106.0.38
Multicast Group = 239.192.106.38
Multicast Port = 5004
Height = 480
Width = 640
X = 0
Y = 0

- CAM17 settings

[Camera Settings]
Camera Name = (h1cam17)
maxX = 659
maxY = 494
Exposure = 3000
Analog Gain = 100
Auto Exposure Minimum = 150
Name Overlay = True
Time Overlay = True
Calculation Overlay = True
Do Calculations = True
Auto Exposure = False
Calculation Noise Floor = 25
Snapshot Directory Path = /ligo/data/camera
Frame Type = Mono12
Number of Snapshots = 1
Archive Image Minute Interval = 0
Archive Image Directory = /ligo/data/camera/archive/

[No Reload Camera Settings]
Base Channel Name = H1:VID-CAM17
Camera IP = 10.106.0.37
Multicast Group = 239.192.106.37
Multicast Port = 5004
Height = 480
Width = 640
X = 0
Y = 0


[The data]
All the data that I took can be found in kiwamu.izumi/Public/measurements/20160830_SRCgouy/data/
The relevant time series are saved with dtt and therefore they are in xml format. The camera images were recorded for each measurement and they are saved in avi format.

Gerardo, John, Chandra

Craned the small scissor lift next to BSC4. Installed wide range hot cathode/pirani gauge and second all-metal valve on bottom existing valve (below CC/pirani pair). Pumped down and valved into main volume. Needs cables.

Left scissor lift next to BSC4.

This morning at about 16:00UTC I made some adjustment to ETMY oplev as per WP #6123. I've included some photos of a 5day trend as well as a before and after 5 the AA reset. THe output power was increased by 7mV in an attempt to stop glitches. I don't know if the after reset pic is of any use as the suspension hadn't quite settled down.

I've re-epoxied Newtonian noise sensors #23 and #25 to their locations on the floor.  These were removed during the HAM6 vent, and I hadn't taken the time to put them back yet.  I still need to tape the cables to the floor - didn't want to do that until the epoxy is cured.

Jim & I put this PS back in the mix after it was off for a couple weeks for routine maintenance--just cleaned it up, checked the spider, and see directly how bad the pump seal leak was.

Attached is the 30 minutes of the servo'd platform positions and the local inertial L4Cs.  You might believe the spike seen on the IPS_Z is correlated with the pressure drop (chans 15 & 16) when we valved in the still slow moving pump.  But that glitch is not exceptional considering others occurring.  The inertial vertical sensors do see some noise along with the Z IPS when the pump is finally up to speed and the servo drops the drive down to put the pressure on setpoint.  It makes sense that the Z sensors would see this DC adjustment as it is the only DOF where the sign of all the sensors are the same (except horz pringle-not shown.) All other dofs have opposite signs cancelling DC shifts this change in DC pressure would produce.

Putting the PS back in service closes WP 5986.

B. Weaver, J. Kissel 

Betsy smartly gathered charge measurements yesterday while the PSL was down so as to avoid the usual Tuesday morning chaos. I've processed her measurements, and they show a similar story as last week. Nothing unexpected here -- we need to flip the bias sign if we have any hope of getting it back down to 0 [V] effective bias before the next observing run.

LHO WP 6119 work has been completed. Monitoring and tuning of the new routers will continue in a non-disruptive manner.

Plots of the water flow rates, after yesterday's work on the flow sensors, are attached.  The early
behaviour looks promising.

Jenne, Sheila, Jeff, Kiwamu, Keita, Terra

Once the laser was back and Corey had finished inital alignment today, we made some progress:

• We followed Koji's suggestion to align the OMC QPDs using OM1 and 2, then picomotored to center on the WFS. The attached screenshot shows the position of the OMs and the movement of the picomotors.  The drives to the OMC suspension are small before we power up now, but we still see large drives as we power up (second attachment shows a comparison of the drives to the OMC suspension from a lock over the weekend to one today).  This must mean that there is a significant difference between the alignemnt of the carrier at the AS port and the sidebands as we power up. 
• We also saw that the OMC QPDs were saturated in full lock, so we turned off 1 stage of whitening (we now have no whitening filters) and reduced the whitening gain from 36 dB to 21 dB. 
• Keita, Kwiamu, Jenne and I followed old alogs with instruction on how to engage both the ISS 2nd and 3rd loops at once (alog 27940).  Today we have been stable enough to turn off the 3rd loop, engage the second loop, and then add the 3rd loop back (we used FM6 and FM9 off, gain of -0.25). We tried to measure the OLG of the 3rd loop in the configuration but could not get a good measurement.  We have added this to the IMC_LOCK guardian, in states called CLOSE_TR_AROUND_SECOND_LOOP and SECOND_AND_TR_LOOPS_CLOSED.
• With both loops closed, the noise in DARM at high frequencies is still dominated by intensity noise, as can be seen from the 3rd attachment. Motivated by this we started some differential TCS tuning with the second loop off so that we are totally dominated by intensity noise.  Our nominal in lock settings have been 0 for CO2 Y and 0.2 for CO2 X, at 2:36 UTC I set CO2Y to 0.1 W, at 3:06 UTC I set CO2Y back to 0, at 3:32 I set CO2 Y to 0.1 and CO2 X to 0.1.  None of these changed the intensity noise, so I tried one more step which caused the rotation stage problem TJ described.  This caused us to be down for 2 and a half hours, but when we relocked the intensity noise coupling was much lower.  The low intensity noise time was at 6:49 UTC, when according to the TCS simulation ITMY substrate defocus was 1.75e-5 diopters, and ITMX was 7e-6 diopters.  I am not sure if we should trust these simulations though, because it looks as though the arm powers may be miscalibrated (?) 
• We sucsesfully in switched the quad coil drivers to the low noise state once using the indiviual coil switching, thanks to Jeff's violin mode damping. 
• We also saw that there was an instability in CSOFT P that was improved by reducing the loop gain.  We reduced the gain in CSOFT pitch, from 0.5 to 0.1, the instability went away but came back and broke the lock when we tried to close the second loop. We have also twice lost lock due to what seems more like the dP dtheta instability after turning on the second and third loops together. We will try to look at these locklosses in the morning.

Note that the DARM spectrum here is not in the low noise state, it is only meant to show that the intensity noise coulping (without the 2nd loop on) changes dramatically with the thermal state of the interferometer.  For now we are leaving the inteferometer in the coil_drivers state, to see what happens with PI.  This means we are at 50 Watts input power, recycling gain of about 23, no ISS second loop, high noise ESD driver, low noise pum states. 

TITLE: 08/30 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: None
SHIFT SUMMARY: Commissioning work continues. The violin modes were rung up a bit from a large eathquake yesterday and Jeff K worked to damp them out. Sheila and I ran into some TCS rotation stage issues that we "fixed" by logging into the system manager and temporarily changing the warning flag values. Meanwhile the TCSX was putting 2W into the IFO so ITMX is a bit hot and still cooling down.
 

There were two versions of the RS screens out there with some differences between the two that has caused some minor confusions today. The older one was mainly just lacking information compared to the new one, so I just made sure that all the links go to the new one now.

Old: (userapps)/tcs/common/medm/TCS_LASER_POWER_CONTROL.adl

New: (userapps)/ioo/common/medm/LASER_POWER.adl

Sheila, TJ

After requesting a power for TCSX from the rotation stage medm, Sheila noticed that the RS was just spinning and not going to the correct power. She promptly hit abort where it stopped at 2W going into the IFO. Requesting a new power did not seem to work, nor did clicking abort one or five more times. This happened last week as well, but last time it mysteriously fixed itself. We weren't so lucky this time. We logged onto h1ecatx1 and pulled open some Beckhoff manuals and tried reading through the errors to diagnose why the RS got stuck. After about an hour or so of digging through errors, we traced it down the RotationstageIn.Warning flag coming from the hardware that may be stuck somehow, so we decided to force the warning to be False in the system manager and then all we well (after remembering to turn the autoabort back on). RS seemed to go to requested powers again without complaint.

When Sheila went to investigate the initial incident, she found that the RS had actually starting moving before a request right before this. She'll give more info on that later.

J. Kissel

After the large Earthquake ~24 hours ago (see LHO aLOG 29359) that tripped all BSCs, the fundamental violin modes have been quite rung up. So I've spent the evening behind the scenes babysitting the gains of the Violin Mode damping -- trying to push the gains us in amplitude to accelerate the damping without saturating the DAC, only slowed by a few failed attempts at switching the PUM coil drivers to a lower noise (and less actuation range) state.

I've basically been following the instructions as defined in Violin Mode Damping 101, and using the table and parameters defined in LHO's Violin Mode Resonances table. Occasionally, I'd get bold and nudge the phase of the filter by 60 [deg] here or there, but for the most part the filter settings as defined by guardian are good. 

If anyone needs them, I've saved some strip tool templates for the modes that were problematic tonight, they can be found in
/ligo/home/jeffrey.kissel/Templates/StripTool/
H1SUSETMX_ViolinFundamentals.stp
H1SUSETMY_ViolinFundamentals.stp
H1SUSITMX_ViolinFundamentals.stp
H1SUSITMY_ViolinFundamentals.stp
Of course, the ranges must be tuned in proportion to whatever gain the damping loops are set, but it's a few less MEDM screens to open and buttons to click to get started.

J. Kissel

While grabbing RMS Current monitors for every suspension to further research the PUM / L2 Current Limiting Watchdogs, I noticed that most of the monitors for the UIM / L1 stage of the H1 SUS ETMY suspension show an offset of -4200 [ct]. This is typically the case when a single leg of the SCSI input cable to the ADC channel is bent and therefore not connected. This problem type was originally documented in LLO aLOG 1857, and found on these particular ADC channels in Nov 2014; see LHO aLOG 14930.

It had been added to the long standing Integration Issue #9 (II #9, now FRS #5135) then, but because it's likely overwhelming generic, I'll open up an FRS ticket for this specific issue. Should be a quick fix.

This is now FRS Ticket #6114.

The new prototype board was modified to satisfy some of the things in the requirement (T1600064) as listed in 1., 3. and 5. below. I also listed things that were not modified but would have been good if recommendations in T1600064 were implemented.

I wouldn't claim that we won't modify it further, but this is just the current state.

In this entry you'll be able to see the electronics modifications in the attached, but the photos are too small to read the original component values, so read the original drawing D1600298 as necessary.

1. Readback of the PD array signal after the servo loop switch ("SUM PE MON")  needed to be DC coupled.

The "whitening" was originally AC-coupled (second attachment) and therefore it was not compatible with digital AC coupling described in the requirement.

We bypassed the big caps in the input of the opamps with some resistors so it acts as one single pole at 2.7k with DC gain of 50 (second attachment, mod 1).

To make the OLTF measurement easier, we made the same change to the whitening downstream of the summation for the excitation DAC output.

The servo board output readback was also AC-coupled, but we want to see if everything is working fine including DC injected into the inner loop board.

We made the output whitening a true whitening (second attachment, mod 2). 0.35Hz zero might be too low, though.

2. The board doesn't implement the analog compensation for the in the inner loop filtering upstream of the error point.

The inner loop error point "whitening" works as a very steep boost seen from the outer loop, roughly an equivalent of (z, p) = ([3; 3; 130], [0.07, 0.07]). T1600064 reccomends to implement the same thing in the outer loop somewhere to cancel this effect to make the loop design simpler.

Since this is not compensated in the prototype board, the outer loop OLTF would become huge for f<3Hz. This means that the digital AC coupling servo should work REALLY hard to effectively AC-couple the entire outer loop at, say, f<1Hz, without reducing the outer loop gain at 10Hz and up.

We do not implement this by analog cut and paste job (no opeamp available for this on the board), but we'll try to make it work by an aggressive digital AC-coupling filter.

3. Integrator as a boost doesn't go well with digital AC coupling so it was converted to a usual boost with finite DC gain.

The error point of the digital AC coupling servo is kept zero at DC (i.e. a pole at zero Hz). The outer loop prototype had an integrator as a boost.

Of course they don't go well as any tiny DC difference between the AC coupling error point and the integrator input will be integrated and eventually the servo runs away. But we don't really need a pole at zero Hz.

We changed it such that the first boost acts as 50Hz LPF with DC gain of 10, and when added to a flat unity gain it becomes 500:50 boost (third attachment) (but see the next entry).

4. Boosts were implemented as three parallel integrators added to a flat unity gain.

We had a choice of unity gain, zp=50:0, 100:0 or 150:0. See the first and the third attachment.

As described in 3. above, we already changed one integrator to []:50 LPF so the boost becomes 500:50.

We didn't fix the parallel summation, it might be OK to go without any boost or using just one.

But T1600064 shows our standard practice of connecting boosts in series.

5. Outer loop servo filters on the board were also changed.

Originally the servo filtering was something like (z,p)=(100, [20^2;40]) (fourth attachment). As described in 2. above, 1st loop effectively adds ([3^2; 130], [0.07^2]). IMC adds another pole at ~8kHz.

Everything added together it's like ([3^2; 100; 130], [0.07^2; 20^2; 40; 8k]), and this might be OK.

But we made a change so the board became ([380;9k],[20^2;600]) by changing one of zero-Ohm resistors in the second stage and one C-R pair in the third stage  (fourth attachment). Everything added together it would be   ([3^2;130;380;9k], [0.07^2; 20^2;600; 8k]).

This change might not have been necessary. We just felt that letting a big 4.7uF capacitor and a zero-Ohm resistor to determine AC gain at around 10kHz in the first as well as the second stage was maybe too much of an uncertainty in the AC gain.

6. Sallen-Key at 0.1Hz for Digital AC coupling path might be too aggressive

For the moment the Sallen-Key is disabled for the digital AC coupling path (so the only analog filtering is a 10Hz LPF) to make things easier as we try to make it work.

Terra and I used the PI damping infrastructure to excite the butterfly and drumhead modes on EY, and then ring them down.

We excited the butterfly mode (6053.9 Hz) during a 50 W lock. The observed ringdown time was 23.5 minutes (= 1410 s), giving a Q of 27×10⁶.

We excited the drumhead mode (8158.0 Hz) during at 2 W lock. The observed ringdown time was 13.5 minutes (= 810 s), giving a Q of 20×10⁶.

The templates containing the spectrum data for these ringdowns live in my directory under Public/Templates/SUS/BodyModes.

Since there seem to be some confusions about which PD has what kind of analog filtering and sent to which channel, here it is.

I'm quite certain about HPO output before AOM (which is "Power monitor PD" in D1002929) and ISS 1st loop monitors, but not that sure about "monitor PD"s in D1002164. E-travellers are incomplete (they don't say which one is installed where), so I'm just listing the nominal values for these "monitor PD"s.