I've taken higher resolution measurements of the .6hz feature. I took 2 measurements over Sunday night, one measurement with a BW of 3mhz and one with a BW of .7mhz. Jeff walked me through calculating the magnitude of the peak and he says that the feature is non-stationary. The calculated magnitude for the .7mhz measurement is 1.17 (not sure of the units, but probably nm/s?), for the 3mhz measurement it's 1.66.  Attach image shows a close up of the peaK, X-axis window is from .55 to .65 hz. Blue trace is the .7mhz measurement, red is 3mhz measurement. If Keith Riles, or some one in DetChar could look at this more closely(specifically a high resolution spectrogram of this), it would be appreciated.

J. Kissel, J. Warner, D. Barker

In order to close out ECR E1400295, WP 4987, and Integration Issue 921, I've removed the remaining old guardian infrastructure from the TMTS, HSTS, HTTS, OMCS and HAUX. This required updating the userapps/sus/common/models/ directory (which removes the guardian block from the common library parts for the OMCS and TMTS), and removing the guardian blocks myself from the HSTS_MASTER.mdl, MC_MASTER.mdl, RC_MASTER.mdl, h1sushtts.mdl, and h1susim.mdl. Once removed, I recompiled, reinstalled, restarted, restored all affected models (basically, every suspension but the QUADs, BS, and P/SR3), and had Jim and Dave help me restore the SEI system and perform a DAQ restart, respectively. All common and site-specific model changes have been committed to the userapps repo.

All old guardian infrastructure has already been removed from the MEDM overview screens EXCEPT for the HSSS, i.e. the RMs, OMs, and IMs. I'll leave that for another day, but that should be that last thing LHO needs to do for this ECR, and it should require no more front-end code updates and/or code restarts.

Note all new safe.snaps have been captured for the affected SUS *before* the computer restarts. I'd confirmed that all *corner station* cavities (via camera views) are well aligned. I did *not* reaffirm the Y arm cavity, and of course this bit me. Sheila had changed the gain for the H1 SUS TMSY OPTICALIGN Pitch to be negative (see LHO aLOG 14161), but never captured a safe.snap for it. For some reason, bringing the TMS to SAFE via guardian reverted the gain to positive, flipping the sign of the alignment offset, which distorted the green / red beam pointing into / out of the cavity. We've since fixed the sign, then captured and commit a new safe. Subsequently *all* new safe.snaps have been committed.
 

I ran a quick P and V TF on the ETMy main chain, since we didn't get an under-vacuum set after the Dec pump down.  The P and V TFs line up well with the model so, so far so good.

Note, we've set the guardian state to PAUSE and the M0 CD STATE request to 1.0 from 2.0 (this switches the analog dewhitening in order to run TFs).

Now that HAM2 and HAM3 are both using the same ground instruments for sensor correction, I looked again at the coherence betwen their sensor correction channels, looking for some possible noise line at 0.6Hz.

I am using the input of the FIR filter bank:

H1:ISI-HAM2_SENSCOR_GND_STS_X_FIR_IN1_DQ

H1:ISI-HAM3_SENSCOR_GND_STS_X_FIR_IN1_DQ

The figure on the left shows the coherence between HAM2 and HAM3 channels.

The figure in the middle shows the transfer functions.

The figure on the right shows the ASDs of HAM3, and the incoherent part betwen HAM 2 and  HAM3 signals. It is well above the theoritical ADC noise, but I don't see any sharp feature at 0.6Hz.

Gerardo, Kyle 

Introduced purge/vent air into X-end sufficient to bring pressure up to 1/2 torr (at request of others) -> The desired result is to better couple suspension temperature to that of VEA room air 

Sudarshan, Rick, Dave:

We successfully got the EY PCAL camera (h1pcalcamy) to pair up with the MSR mac-mini (h1pcaly) this morning. When Rick and I tried this just before the holidays, we suspect too long a period of time expired before we could try the pairing (we physically moved the mac-mini between EY and MSR). Today Sudarshan used the camera's menu to reload the h1pcalcamy network configuration back into the UT-1 network adapter and the mac-mini connected automatically. I took a picture of ETMY (attached). We will test EY at regular periods today.

We will do the same with EX after lunch.

WP #4966

The following software has been updated for Ubuntu control room workstations:

awgstream (no change, recompile against new libraries)
gds (foton, diaggui, diag, chndump, awggui, dmtviewer, and others) fix bugzilla 288, 754, 755, 760, 761.
nds2-client  (nds2_channel_source, nds2-tunnel, nds-client-config, nds_query)
root (CERN root libraries and root)

OS X versions of the software will be updated next week.

Due to Dave's ADC reboots at EY, I've taken the TMSy and ETMy guardian states from ALIGNED to SAFE.

Turbo rotor left elevated for now

I've lowered the temperature setpoint for the XEND VEA back to 65F (down from 67).  In order to do so I have turned off the single stage of heat. We'll probably see some overshoot.

no restarts reported.

Actually this is for the past two weeks.

The variation in the frontend laser's pump diode output power coincides with a dip in the relative humidity
in the diode room.  Not surprisingly the relative humidity change is also indicated by the sensor inside the
high power oscillator.  If this signal was used as an alarm, which was intended to detect the suspicion of
a water leak, the laser would have been automatically shut down.

Everything else looks nominal with the only exception being related to the site-wide power glitch.

Attached are some comparison images of ETMy before and after it was cleaned just before Christmas.  I have also attached a pitcure or ETMx before it was cleaned, although it is taken at a much longer exposure and is not as well focused making direct comparision of images difficult.  The three very bright spots which were previously visable on the ETM are no longer visible, these would  have been the three macroscopic pieces of first contact which were removed from the mirror.

Imaging method:

  The camera position is identical in the before and after images.  For all pictures, an image is taken with the test mass is illuminated with IR locked in the arm.  The trans mon is misaligned so there is minimal green light present.  A background image is taken with no IR (ITM misaligned), and this is subtracted from the original image to produce the final image.   The analogue gain is set to 100, a 12 bit image is taken, and each image is made of 100 averages.  The exposure of the ETMx images is 10000micoseconds, and ETMx is taken at 500000 microseconds.

BRDF calculation:

Done using the same method as alog15633, with calibration factor 1.6x10^-10 (µs)(W)/count (same as before).  The incident power is calculated by averaging ASC-TR_A_SUM_OUTPUT and ASC-TR_B_SUM_OUTPUT as outlined by Dan in alog 15431.

ETMy shows a factor of ~6 improvement since being cleaned, but it still doesn't look as good as ETMx.  I will see if I can focus the camera better on ETMx to get a nicer comparison.

J. Kissel, B. Shapiro

The summary says most of it -- we've confirmed with two degrees of freedom of top to top transfer functions. Our best candidate is that the temperature in the VEA is too high. I tried adding a vertical offset in either direction, in hopes that we have enough range to recover the drooping, but it appears we do not. We'll first try restoring the XVEA temperature (if not surpassing it), but we may have to vent again. Cross your fingers.

Details:
Hoping that we could test the newly turned on H1 SUS ETMX ESD for functionailty, Brett and I noticed the optical lever did not appear centered in either the misaligned or aligned state. We could only restore the optical lever centering by putting the alignment offsets at 
                       P        Y       
Force Realignment    +21.3    -122.9
Original Aligned    +417.0      77.2
Change              +395.7     200.1
Further, I noticed that a P request would cause both P and Y motion, and vice versa. 

Betsy then trended the temperature in the VEA, see LHO aLOG 15877, and found it ~2 [deg F] or ~1 [deg C], which corresponds to about 100 [um] sag at the TOP mass (see T1400749, specifically LLO aLOG 15636. I note that this is at the TOP mass, because the lower stages will sag MORE, since there are cascading vertical blade springs.

We then, in the interest of time, took the transfer functions we know are the most sensitive to rubbing: P to P and V to V. These transfer functions are attached, for the various vertical offsets applied; see 2015-01-05_2358_H1SUSETMX_M0_Mono_WhiteNoise_*_0p01to50Hz.pdf. The vertical offsets were +/- 200 000 [ct], equivalent to most of the DAC range, which is roughly +/-115 [um_pk]. We can clearly see that the first several modes have shifted significantly, and several DOFs are cross-coupled in. Notable, however, is the highest-frequency modes are unaffected. This implies that the top-mass is free, and the lower masses are restricted, as seen in a QUAD's mode shapes. This makes sense, because for this most recent cleaning (see LHO aLOG 15744), the *only* activity in chamber was to clamp the test mass briefly for cleaning. Further, sadly, even with 100+ [um] of displacement in vertical, we could not move the the suspension free.

Note, we checked the reaction chain with P and V TFs, and it appears free and clear (see 2015-01-06_0152_H1SUSETMX_R0_WhiteNoise.pdf). We did not check the TMS, since it was not touched.

Finally, because we were amazed that the SUS had sagged more that 100 [um], and that we know that Betsy set the EQ stops when the VEA was at ~70 [deg C], Brett compared the top-mass displacement of the main chain, reaction chain, and TMS to gauge the amount of displacement compared to the other SUS in the chamber, which should have roughly comparable sag because they've the same blade springs and overall suspended mass (roughly). We attach two trends, EX_SAG_21DecTo5Jan.png (a 15 day trend that includes the pump down) and EX_SAG_22DecTo5Jan.jpg (a 14 day trend to zoom in on the long term temperature equilibration). From the 21st, one can see that the removal of air [the first big sharp drop], caused all SUS to drop. However, the main chain is expected to drop 170 [um] (see T1100616), and the reaction is expected to drop 100 [um]. While the reaction chain drops as expected, the main chain only drops ~125 [um], indicating a sort of bottoming out. Further, from the 22nd's trend, we see the temperature dependence is different (the bias has been removed for clarity). 

So, again. Bad news. Hopefully we can pull this SUS back up with temperature!

Sheila, Thomas, Elli, Evan

We locked the Y arm in IR, and then turned on WFS loops which feed back to IM4 and PR2 in order to keep the buildup in the arm maximized. We measured the dc counts on ASAIR_A_LF. Then we unlocked the arm and measured ASAIR_A_LF again. The results are as follows:

• ASAIR_A_LF_OUT, locked: P_on = 1205(5) ct
• ASAIR_A_LF_OUT, unlocked: P_off = 1300(10) ct
• LSC-Y_TR_A_LF_OUT, locked: 11.4(1) ct

Using the formula in LHO#15470, the locked and unlocked values of ASAIR give an equivalent loss of 267(31) ppm on ETMY.

To account for the power in the sidebands, we use the modulation depths given in LHO#15674: Γ₉ = 0.219(12) and Γ₄₅ = 0.277(16). Then the power in the sidebands is P_SB = P_off × (Γ₉²+Γ₄₅²)/2 = 81(7) ct. Then using our new value for the power fraction, A² = (P_on − P_SB)/(P_off − P_SB), we get an equivalent loss of 286(33) ppm on ETMY, not accounting for mode mismatch.

Last year, we thought we had found a configuration using sensor correction on HEPI that worked on HAM3. I was looking (Krishna was, too, he saw it first) at the summary pages over break and noticed that HAM3 still looked like it had the .6hz peak. I came in this morning, checked the configuration and did an on/off measurement, and HAM3 still has the same issue, even when we correct to HEPI instead of the ISI, contrary to what we found last time. See attached plot. Solids are measurement taken with sensor correction off, dashed are with HEPI sensor correction.