DAY Operator Summary (finishing off Patrick's shift)

Covering the latter part of Patrick's shift from 22-23utc (2-3pmPST).  Here are activities:

• 22:07 Tranfer functions complete for ITMy (Kissel)
• 22:09  swapping in new TCS chiller (was a back up) to replace leaky one & then checking for leaks in LVEA (Greg)
• 22:11 LVEA is now Laser HAZARD (Bubba transitioned)
• 22:14 MY (maybe also EY) to make measurements) (Bubba, & Mark)
• 22:22 IMC work (Jenne at IOT2L & Cheryl at PSL)
• 22:22 Going to Squeezer Rack (Nutsinee)
• 22:33 EY is now Laser SAFE (Evan)
• 22:44 PCal Group back (Travis, Darkhan, Evan, Rick)

23:00----OPS Meeting Time

End Of Ops DAY Shift

HEPI Closed Loop Range of Motion test shows Oplev Len2Angle coefficient makes sense

and there may be a minor amount of yaw coupling.

The attached 25 minute time series shows a +-200000nm drives in X & Y on ETMX. This offset into the ISO loop is ramped in for 120 seconds.  The upper left plot shows the ISO_RZ output keeping the computed RZ_LOCATIONMON at zero.  The lower right plot X_LOCATIONMON is used to calculate the Length to angle coupling on the Optical Lever output:

OpticP(Y)[urad] = OplevP(Y)[urad] - LengthDrive[nm] * Len2Pit(Yaw)CC[mrad/m] * 1e-9[m/nm] * 1e3[urad/mrad];    Len2Pit(Yaw)CC from E1200836: 20.89 (11.9)mrad/m

So in the two upper right plots, the Pitch and Yaw expected to be seen on the Oplev due to the X motion are, shown in blue and subtracted from the raw Oplev output (red) giving the residual in black.  We believe the HEPI calculations for position are very good and our loops hold things at those positions.  With that assumption, we'd expect most of the signal seen on the OPLEV is from the drive.  As the residual during the X drive is small (<20%,) maybe this suggests the coefficients in E1200836 are not too far off.

So, for ETMX, certainly most of Pitch and Yaw seen on the optical lever when driving X is from the Cross-coupling effect.  But there appears to be some actual optic YAW from these HEPI translation.  There is no a priori cross-coupling from Y motion on ETMX as the Optic shears across the optic normal.   The YAW seen during the Y translation is twice as large as during the X motion suggesting that even with our loops closed, we are still getting some YAW at the optic..

This is pretty small and obviously the ASC loops are managing with this and when do we ever translate the optic 200um?  Oh, yes, for tidal relief...

 

Ops Shift Summary

TITLE: 01/11 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
LOG:

Corey covering from 22:00 UTC to 23:00 UTC
Operator meeting at 23:00 UTC (no coverage)

15:07 UTC Chris to LVEA to retrieve clean and bake items for Betsy
15:56 UTC Mark and Tyler to LVEA to retrieve equipment for Rick. Craning equipment over beam tube.
16:28 UTC Mark and Tyler done
16:45 UTC Bubba to end Y
16:48 UTC Gerardo to LVEA to check on aux pump cart by HAM5
16:55 UTC Ed to LVEA to stage cable for WP 7279
17:09 UTC Gerardo back
17:16 UTC Mark and Tyler to end Y to retrieve equipment through outer rollup door
17:16 UTC Jeff B. starting WP 7280
17:18 UTC Ed and Filiberto starting WP 7279
17:39 UTC Bubba back from end Y
18:13 UTC Bubba to LVEA to look for legs for scaffolding
18:19 UTC Bubba back
18:20 UTC Marc to LVEA to look for Filiberto
18:26 UTC Mark and Tyler done at end Y
18:42 UTC Chandra to mid Y and end Y to check on things
19:07 UTC Ed and Filiberto done pulling cables. Ed making pigtails. Cables need to be terminated. Filiberto starting connection of TCS laser to safety system on mezzanine.
19:08 UTC Travis to optics lab to get IR viewer then cleaning area to get headsets.
19:12 UTC Gerardo to LVEA to turn off aux pump cart by HAM5
19:18 UTC Jeff B. out of LVEA
19:19 UTC Travis back
Gerardo back
19:32 UTC Cheryl to IOT2L to install beam block
19:43 UTC Yannick to LVEA to take pictures of PEM devices
19:56 UTC Betsy to LVEA to drop off wipes
19:59 UTC Jenne to join Cheryl at IOT2L table
20:04 UTC Betsy back
20:09 UTC Yannick back
20:45 UTC Jenne and Cheryl back
20:52 UTC Jeff K. taking transfer function on ITMY reaction chain
20:55 UTC Rick, Travis, Evan, Darkhan to end Y for PCAL
21:00 UTC Vent meeting in CR
21:03 UTC PCAL group transitioning end Y to laser hazard
21:37 UTC Ed and Filiberto to LVEA to continue cable pulling
21:54 UTC Bubba transitioning LVEA to laser hazard

Vent meeting notes

No planned intervention on PSL
cdsfs0 restart scheduled for ~ 6am next Tuesday
PSL locked/tagged out after laser damage found on IOT2L table panel yesterday
Leak checking done
Plans to install ion pump on CP7
Vent meeting scheduled for next Tuesday at 9:30 am (due to Monday holiday)
Investigation of slightly strange ITMY reaction mass transfer function
HEPI pump maintenance continues
end Y HVAC changes to mitigate temperature increase
Scaffolding to be installed between HAM2 and IO table over HEPI piers tomorrow
Bubba has ALS and PCAL lasers locked/tagged out

Beam dumps added to IOT2L

[Cheryl, Jenne]

We added a few beam dumps to IOT2L, just in case the IMC Refl beam gets moved far enough that it's not going to the designed mirrors and beam dumps.  There is one large dump behind the top periscope on the refl path, and one each behind the 2 high power dumps that dump most of the power. 

EY purge air

I dialed down EY purge air so not all five compressors are running, to help with temperature control in the mechanical room. After adjustment one pump turned off. I think we nominally run on just three at a time, but the soft cover on BSC 10 was not billowing very much so I didn't want to reduce flow much more.

DP measured -16degC. Not great, and it maybe would have dropped slightly more if I had more time to measure before rushing to meetings. It's also raining outside.

 

New H1 SUS ITM QUAD's V4 ('Bounce') and R4 ('Roll') Mode Frequencies and Qs Post BRD Install

J. Kissel

Using similar techniques as described in LLO aLOG 28503, I've characterized the ITMs new highest bounce and roll (V4 and R4) -- namely the new frequencies for ITMX, and the Quality Factors of modes after installation of the Bounce Roll Mode Dampers (BRDs). The results are tabulated below.

                                ITMX               ITMY

    V4 Frequency / Hz      9.797  (0.001)      9.816 (0.001)

    V4 Q / dim.less        4770   (15)         1237 (0.88)

    R4 Freq / Hz           13.902 (0.001)      13.898 (0.001)

    R4 Q / dim.less        2840   (11)         1406 (3.2)

(The uncertainties quoted for the Q are the 68% C.I., 1-sigma [sqrt of the] weighted sample variance resulting from 3 measurement trials on each mode; the value reported is the weighted mean of the three trails. See more details below. The uncertainty on the frequency is simply the requested binwidth of the ASD used after finding the mode frequency.)

Remember, the goal for these BRDs was to reduce the Q of the V4 and R4 modes from ~10^6 to "one to several thousand" (see pg 6 of G1600371, and thermal noise impact discussion in T1500271). 
These Q results are consistent (if not a little lower) than LLO's values, and are within the desired specification. 

A successful implementation of the BRDs!

%%%%%%%%
Details
%%%%%%%%

Measurement Technique:
    (1) explore the expected V4 / R4 frequency range to find the mode frequencies. 
        - Drive M0 Main Chain Top Mass in Vertical and Roll (I drove out the TEST bank using AWGGUI), using broad-band uniform noise, with a 200 mHz 4th order elliptic band-pass surrounding the expected frequency. You may have to shift the band-pass filter around a bit in the search.
        - Measure the response in L2 OSEMs (in L, P, and Y), L3 Optical levers (in and Y), while watching for digital saturation of the DAC on the M0 LF and RT OSEM chains.
        - Attached are the successful awggui settings during this mode search phase
    (2) Drive up the found V4 / R4 frequencies with pure sine-wave, stop the drive suddenly, and record GPS time
        - Use the maximum DAC range on the M0 drive (which means you can't drive V and R at the same time)
        - Attached is the raw DTT ASD of the above mentioned sensors during the Sine Exc, using the attached awggui settings. The drive level shown is just below DAC saturation.
    (3) Wait for ~1-2 hours for the mode to ring down (not because the Q is that high, but because you want 1-2 hours of excitation-free data for high resolution ASDs during later analysis)
    (4) Rinse and repeat steps 2 and 3 to have several measurement trials (I used three trials)
    (5) Use /ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/BandR_damping_plot_Q.m to analysis each trial's ring down
        - The Q is determined by fitting the decay of RMS of the displacement ASD at the mode frequency to an exponential, A*exp(-t/Tau), and extrapolating the Q as Q = pi*f0*Tau.
        - The FFT, bandpass filter, and RMS parameters/settings play an important roll in the resulting RMS data, so one must play around with these a bit for each mode to find the right settings for all trials of a given mode. For example, if your band-pass is too narrow (say 1 mHz), then the resulting RMS will include some of the non-excited data / impulse response of the filter, which confuses the resulting RMS making it look like a really large Q. However, once you're happy (namely, when the RMS time series remains roughly the same for small changes in analysis settings -- and the same settings give consistent results for all trials), the settings should remain fixed, if possible, for all trials of a given mode.
        - The initial guess of the amplitude A also affects the fit, simply because it is arbitrary when your ~1.5 hour data set starts w.r.t. where the ring-down begins. 
        - The value and its uncertainty is reported by the Matlab built-in "fit" function, and the 68% confidence intervals are reported on the fit object using confint.
    (6) The results are averaged for each mode in /ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/BandR_trials_comp_Q.m, which takes the weighted mean, and weighted sample variance (as well as the standard error on the mean).

The .pdfs attached cover the results of all the data analysis. 

ITMY M0 (LF RT) / R0 (LF RT) OSEM signal chain

Following up on alog 40014 with reported issues on MO and RO signal chain. Looked at possible grounding issues. Tested cable SUS_ITMY-8 at satellite box and found pin 2 shorted to chamber ground. To eliminate the air-side cable, we tested directly at the feedthru. Same results, pin 2 shorted to ground. The AA/AI/Coil driver driver electronics were also power cycled.

FRS Ticket 9683

Sadly, no change in the R0 V and R transfer function performance (composed of OSEMs LF and RT) after the the shorts were identified (and therefore cables re-seated), nor after the power-cycle of the signal chain. Remember, the SUS_ITMY-8 cable Fil refers to is ITMY's M0 (LF RT) / R0 (LF RT) cable between the satellite amp and the chamber feedthru (see D1100022).

Attached are the results.
Maybe one could argue that the 1.11 1.70 2.82 4.52 5.90 (+/- 0.01) Hz features originally called out in LHO aLOG 40014 have been slightly reduced, but I'm not sure if it's related.

SHG is locked!

Daniel, Sheila, Terry, Nutsinee

 

We locked the thing!

Below are some of the relevant information:

 

Broad Band PD at SHG transmitted (Design document: https://dcc.ligo.org/LIGO-T1100467)

Responsivity (1064) = 0.1A/W

Transimpedance = 2kOhms

Calculated power hitting the PD = 10mW

 

EOM1 (Newport 4004 Broad Band Phase Modulator)

Modulation response = 15 mrad/V @1000nm

Drive voltage = 1.5Vp (1Vrms)

Modulation Depth = 22.5 mrad

 

Other values:

Measured transmitted DC level = 2V

Measured RF power envelope (peak-peak) = 8mV

Measured PDH error signal (peak-peak) = 40mV

FSR of the SHG cavity = 3GHz (cavity length ~2.5cm, KTP crystal index of refraction = 1.80302 gives 2.75 cm extra path length. This 3GHz number was also found buried in SURF report by Nathan Zhao)

Finesse = 89.75 (used r=0.9, value for the input coupler) I mistyped the % earlier. Finesse is just a number, not percentage.

Calculated Linewidth = 30MHz

 

Open-loop gain transfer function

The boost labels on the medm screen are still wrong. That's due to be fixed.

The first boost in the common path is actually 0/10 (pole/zero) and the second boost is 40/200

The "boost" in the slow path is actually "compensation" (4/400) and the "compensation" is just a pole at 100kHz with no zero.

TF WITHOUT common path second boost engaged has UGF at ~850Hz

TF WITH common path second boost engaged has UGF at ~1.5kHz

 

Other stuff worth mentioning

• SHG TEC control is now working
• SHG and CLF common mode board retested after the wrong wiring was fixed-- they're good

Pcal work at Yend yesterday

TravisS, DarkhanT, EvanG, RickS

Late yesterday afternoon, we transitioned to Laser Hazard at Yend (removing Bubba's Lock and Tag on the Pcal power supply after consulting with him).

After orienting the ETM to the pre-vent location on the QPD, we went into the manifold and inspected the Pcal beam positions on the perisocpe relay mirrors.  They looked pretty good on a cursory inspection.  Both beams were also found to be centered on the Receiver module power sensor.  Evan and I centered the beam positions on this sensor before the vent.

Then, using the Working Standard, we measured the beam powers before entering the vacuum enclosure, inside before impinging on the ETM, inside after reflecting from the ETM, and outside at the Receiver Module.  These data, once digested, should allow us to determine where the approx. one percent optical loss between Transmitter and Receiver modules is occurring and thus reduce the Pcal uncertainty slightly.

We then transitioned back to Laser Safe, re-installing Bubba's lock and tag on the Pcal power supply.  Note that the green light supply is not locked out, but the key is removed.

At the next opportunity, we plan to install the Pcal ETM target on the suspension structure and investigate the alignment in more detail.

E Y Temperature Increase

There was a slight temperature increase, ~1 degree F.in the VEA late yesterday. Part of this can be attributed to increased activity (both personnel and clean rooms running)and partly due to the increase in temperature in the mechanical room adjacent to the VEA which houses the purge air compressors. The temperature in that room increased to 86 degrees F and some of that warm air likely migrated to the VEA. 

I went down to the end station late yesterday and checked the glycol level/pressure, which normally operates at 30psi and that pressure was down to ~24psi, not enough to make a  temperature excursion of 1F. I topped off the glycol bringing the pressure up to 30psi.
I also increased the air flow of the supply fan from 60% to 80%. This is a common practice when we fire up clean rooms in the L(VEA)s. I will continue to monitor the temperature and make further adjustments as needed. 

Current set point in the VEA is 65F-current temp is 65.6F. 

HPO diode box 1 temperature

Over the past day the output of the oscillator has slowly declined (~5W).  I adjusted the diode box temperature, rather than the diode current, to compensate.  We gained some output power back.  It might be that the oscillator can be nursed in a better way by tuning the temperatures of the individual pump diodes of diode box 1 but that will take some time.

GV11/12 Hard Closed and CP4 Coupled to Local Ion Pump

(Chandra, Gerardo)

Hard closed GV11 and GV12, this was done in preparation for CP4 bake, at 23:03 utc a small 75 l/s ion pump was coupled to CP4 vacuum volume to remove H₂. 

Something to note, during the closing of the gate valves, GV11 made a loud noise, visible on some of the local seismometers, also the annulus system for this gate valve responded by going up on current, went from 1 light to 6 lights.  GV12 did not make any noise and its annulus system did not show any changes.

To couple the new ion pump to CP4 we followed the steps listed on WP#7270.

HAM5/6 Annuli Pump Down

(Bubba, Gerardo)

Removed and replaced the rubber stopper size 1 from HAM6 north door annulus, replace it with a size 0.  Pumped down on system with an aux-cart and pressure as of 19:00 utc was at 8.0x10^-6 torr, aux cart will remain on until tomorrow.

MC2 Trans QPD - three beams, only one that we want

Attached is a picture of MC2 Trans QPD during the initial alignment when I devised a setup that used a red laser pointer to mimic the IMC beam, to align the MC2 Trans QPD.

In the images, there are three beams. 

Through careful evaluation, Keita and I determined that the upper left beam is the second internal reflection from MC2 (vertical wedge), the far right beam is a reflection from the black glass that's behind the curved steering mirror to the QPD, and the center beam (slightly clipped on the edge of the QPD aperture, since it was not yet aligned) is the real MC2 transmitted beam that we want to center on the MC2 Trans QPD.

Tests to evaluate the likelihood that the alignment into the IMC could be altered in such a way that one of the two beams we do not want to use ends up on on MC2 Trans QPD are under way.

Rubbing Check Measurements on ITMs -- ITMX Great, Suspicious behavior of ITMY V and R DOFs

J. Kissel

Wrapping up the core optic suspensions standard rubbing check top-to-top transfer functions after pump down, I've measured the main (M0) and reaction (R0) chains of H1SUSITMX and H1SUSITMY. 
ITMX looks great and free of rubbing, no "ifs," "ands," or "buts".
ITMY shows poor response / low coherence in both main and reaction chain vertical.

Conclusion: (albiet a weak conclusion) I suspect something is awry with the ITMY M0 (LF RT) / R0 (LF RT) OSEM signal chain, with a slight preference toward it being a drive problem. I *hope* that it's an external-to-chamber problem.  More discussion below. 

Attached are the results.

Discussion of ITMY:
- Start with the comparison between previous measurements, allquads_2018-01-05_H1SUSITMY_All_Phase3b_ALL_ZOOMED_TFs.pdf, and flip to pages 3, 9, and  10 for the M0 V to V, R0 V to V, and R0 R to R. 
NOTES: 
    - These are particularly low coherence, and these are driven with the same excitation amplitude as ITMX. 
    - I tried to drive harder, in case the templates were tuned for some other configuration, and it saturates the DAC, so the templates *are* well tuned. 
    - As per normal, I was in the top coil driver state 1, i.e. that with the low-pass OFF, and therefore the most DAC range.
    - Also, there are features in the R0 R to R transfer function at 1.11 1.70 2.82 4.52 5.90 (+/- 0.01) Hz that don't correspond to any other DOF's resonances for either chain.

- Next look at the individual measurements detailed TF analysis, 2018-01-05_1944_H1SUSITMY_R0_ALL_TFs.pdf. Pg 3 and 4 are repeats of what you've seen, but 
NOTES: 
    - on pg 7 (L to V), pg 9 (R to V), pg 11 (P to V) which show the "expected" or "interesting" cross-coupling between the vertical DOF and others, one sees pretty good reciprocity. I.e. we see that what features and frequency response shape are seen in the V to ? TF are also seen in the reciprocal ? to V transfer function. This is evidence toward the sensors/electronics being a problem and not the suspension's dynamics. Admittedly, the P to V and V to P TFs look the least alike. These TFs *have* changed from the previous at-vacuum measurement of this suspension (see 2017-07-20_2358_H1SUSITMY_R0_ALL_TFs.pdf from LHO aLOG 37848), but it's unclear if one could claim that one was "better" or "more right" than the other.
    - on pg 15 (V to LF RT) and 16 (R to LF RT), one can see that both sensors are showing the same response to the drive (as was true in 2017-07-20 data set as well), but it just looks over all weaker. This implies that it's a *drive* electronics problem, not a *sensor* electronics problem.

A final note: other than
    - Aligning / Rebalancing the Reaction Chain,
    - Installing BRDs & NMBDs on the Main Chain, and
    - Resolving all in-vac cable grounding issues
we did comparatively little to this suspension.

Following all these clues, I was perusing aLOGs to see if I could find any hanging chads regarding the cable grounding issues, and found LHO aLOG 39675, but 
    (a) Those cables in question for ITMY were for R0's (F1 F2 F3 SD) and PUM (UL LL UR LR) signal chains, *not* for those involved with these transfer functions, namely the M0 (LF RT) / R0 (LF RT) signal chain, and
    (b) Richard assures me that *every* grounding issue in that aLOG was resolved (confirmed quickly by Besty in passing by LHO aLOG 39749)

As a final test, I ran the R0 V to V transfer function with all DOF's damping loops CLOSED -- see 2018-01-05_2214_H1SUSITMY_R0_V_Damped_WhiteNoise_0p01to50Hz.png for the results (BLACK is the 2017-12-20 data set, MAGENTA is the latest 2018-01-05 undamped data set shown the analysis .pdfs, and RED is the damped data set).
The only major difference (besides the -- surprisingly in-effective -- reduction of the primary vertical modes), is that the extra 1.11 1.70 2.82 4.52 5.90 (+/- 0.01) Hz features are reduced to the in-air 2017-12-20 level.

Measurement Templates:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/
ITMX/SAGM0/Data/2018-01-05_1828_H1SUSITMX_M0_WhiteNoise_L_0p01to50Hz.xml
ITMX/SAGM0/Data/2018-01-05_1828_H1SUSITMX_M0_WhiteNoise_P_0p01to50Hz.xml
ITMX/SAGM0/Data/2018-01-05_1828_H1SUSITMX_M0_WhiteNoise_R_0p01to50Hz.xml
ITMX/SAGM0/Data/2018-01-05_1828_H1SUSITMX_M0_WhiteNoise_T_0p01to50Hz.xml
ITMX/SAGM0/Data/2018-01-05_1828_H1SUSITMX_M0_WhiteNoise_V_0p01to50Hz.xml
ITMX/SAGM0/Data/2018-01-05_1828_H1SUSITMX_M0_WhiteNoise_Y_0p01to50Hz.xml

ITMX/SAGR0/Data/2018-01-05_1923_H1SUSITMX_R0_WhiteNoise_L_0p01to50Hz.xml
ITMX/SAGR0/Data/2018-01-05_1923_H1SUSITMX_R0_WhiteNoise_P_0p01to50Hz.xml
ITMX/SAGR0/Data/2018-01-05_1923_H1SUSITMX_R0_WhiteNoise_R_0p01to50Hz.xml
ITMX/SAGR0/Data/2018-01-05_1923_H1SUSITMX_R0_WhiteNoise_T_0p01to50Hz.xml
ITMX/SAGR0/Data/2018-01-05_1923_H1SUSITMX_R0_WhiteNoise_V_0p01to50Hz.xml
ITMX/SAGR0/Data/2018-01-05_1923_H1SUSITMX_R0_WhiteNoise_Y_0p01to50Hz.xml

ITMY/SAGM0/Data/2018-01-05_1828_H1SUSITMY_M0_Mono_WhiteNoise_L_0p01to50Hz.xml
ITMY/SAGM0/Data/2018-01-05_1828_H1SUSITMY_M0_Mono_WhiteNoise_P_0p01to50Hz.xml
ITMY/SAGM0/Data/2018-01-05_1828_H1SUSITMY_M0_Mono_WhiteNoise_R_0p01to50Hz.xml
ITMY/SAGM0/Data/2018-01-05_1828_H1SUSITMY_M0_Mono_WhiteNoise_T_0p01to50Hz.xml
ITMY/SAGM0/Data/2018-01-05_1828_H1SUSITMY_M0_Mono_WhiteNoise_V_0p01to50Hz.xml
ITMY/SAGM0/Data/2018-01-05_1828_H1SUSITMY_M0_Mono_WhiteNoise_Y_0p01to50Hz.xml

ITMY/SAGR0/Data/2018-01-05_1944_H1SUSITMY_R0_L_WhiteNoise_0p01to50Hz.xml
ITMY/SAGR0/Data/2018-01-05_1944_H1SUSITMY_R0_P_WhiteNoise_0p01to50Hz.xml
ITMY/SAGR0/Data/2018-01-05_1944_H1SUSITMY_R0_R_WhiteNoise_0p01to50Hz.xml
ITMY/SAGR0/Data/2018-01-05_1944_H1SUSITMY_R0_T_WhiteNoise_0p01to50Hz.xml
ITMY/SAGR0/Data/2018-01-05_1944_H1SUSITMY_R0_V_WhiteNoise_0p01to50Hz.xml
ITMY/SAGR0/Data/2018-01-05_1944_H1SUSITMY_R0_Y_WhiteNoise_0p01to50Hz.xml
ITMY/SAGR0/Data/2018-01-05_2214_H1SUSITMY_R0_V_Damped_WhiteNoise_0p01to50Hz.xml

Opened FRS Ticket 9683 to track this issue.