9:15 Fil Aaron to EX working on cabling
10:00 Alastair to LVEA TCS-Y table
10:15 Hugh, Gerardo to LVEA
10:30 Alexa transitioning EY
11:30 JeffB to LVEA, moving SUS pallets for 3IFO
11:00 Kyle to EY cleaning up tools, done 12:00
13:00 JeffB, Bubba to LVEA looking at craning operations around High Bay, out 13:15
14:00 Gerardo to LVEA
14:30 Hugh, Suresh to HAM2 HAM3 for oplev work
K. Venkateswara
I had installed temperature sensors on BRS and GND_T240 yesterday as described in 14825. The first plot shows the trend over a day along with the PEM_VEA temperature sensor. The count to Kelvin conversion was expected to be 1.56e-3 K/count. This seems roughly consistent with the temperature of the T240. The BRS temperature sensor shows a lower magintude and a phase offset due to it's extra thermal shielding and larger mass.
The attached pdf shows the ASD of the temperature sensors and the coherence between them and their respective instruments. The temperature sensors are mostly limited by ADC noise. An op-amp based pre-amp of 50-100 gain would be useful. BRS_RY_Out shows a little bit of coherence near few mHz while T240 X, Y and Z show no coherence with the temperature sensor.
You should add the ADC noise to this plot
I've added a comment about it in 14909. I'm not sure how to display the ADC noise in DTT. In any case, it shouldn't be limited by ADC noise any more.
J. Warner, K. Venkateswara
We have turned on sensor correction on Z and X at ETMX since noon today.
Z on ETMX had been switched to TBetter blend by an unknown person during the weekend. Jim switched it back to the 90 mHz blend(Ryan's LLO blend). We then also turned on the X sensor correction which is currently using the tilt-subtracted super sensor.
The first two pdfs show the before and after plots for the two configurations. Before was taken ~3 am this morning and after was at ~12 noon. Note that the improvements in Yaw/Pitch at low frequencies were largely due to going to the 90 mHz blend and then using Z sensor correction.
The third plot shows the improvement in X and Z transfer functions from the ground to Stage 1 before and after the configuration change.
It seems to be helping over a large frequency range above 10 mHz and not hurting anywhere, so we will leave it on for overnight monitoring. If it affects commissioning in any way, it is easy to turn off through the ISI screens.
edit: Z sensor correction is to HEPI_IPS and X is to Stage1_CPS
J. Kissel, J. Warner In the "after" configuration, given that the coherent linear transfer function ("SCimprovement.pdf") only shows a factor of a few amplification at 50 [mHz], yet the ASD shows a factor of 20-30 amplification, I argue that this is even more evidence for re-injection of residual tilt noise of ST1. I haven't done the usual X_blend * RY * g/w^2, but I've suggested that Jim try to play around with the RY blend filter (i.e. just use one of the other blends we already have in the bank) and see if the change in performance of RY improves or worsens the X performance. #weneedamodel P.S. The optic looks like it was misaligned for the "after" measurement, or there was a laser glitch during the measurement, because the optical lever noise floor seems supremely high, and I'm confident does not reflect the displacement of the optic. The "before" looks OK.
As a follow up to my alog showing the H1 science frame usage per subsystem, I've found a way to show this as a readable pie chart
Gerardo & Hugh
We recentered these oplevs to make better use of their tracking. And especially HAM2 as it seemed to be way off on one quadrant. Luckily we didn't lose the beams.
First attached is a three day trend showing yesterdays fun with HAM2 and the recentering this morning.
Next is the last eighty minutes, maybe given the wandering, the X-Y plots on the medm should have their window zoomed out some. This seems to be an issue mostly on HAM3 Yaw.
The third plot shows the five hour detail around yesterday morning on HAM2 with the HEPI Cartesian RZ (yaw) RY (pitch) and HP, the horizontal pringle mode. This further shows even though the HEPI RZ has servo'd back to its reference, the OpLev Yaw would disagree. Likewise, even though the HEPI pitch shifted way off for most of the time and then came almost all the way back, the OpLev Pitch doesn't follow that in any reasonable way. Even though these OpLevs have no caibration as I understand, this says alot about system distortion. I've included a feducial from the large shift in the HP calculation but it doesn't appear to correlate to anything in the OpLev response.
The last paragraph about the last plot is confused by the reversed Pitch and Yaw of this OpLev, see 14965.
I wanted to try turning on HEPI sensor correction at EY this morning, but I've run into an issue. When I turn on just the new Mitt_sc filter no numbers come out of the outputs. However, when I turn on the filters associated with the fir sensor correction, numbers come out. Even when I just turn on the path, with no filters engaged, numbers come out of the output block. Something about engaging the sensor correction filter completely cuts the signal. I will try copying the filter to a different fm when I get a chance.
I screwed this up. Dave found that I had installed a filter with a gain of something like 10^-11, then fixed the gain, but never loaded the code into the front end. So foton showed a reasonable filter, but the front end was running a filter with a gain of zero. This is fixed now.
As the wandering laser intensity continues I intend to learn more about these systems. I can only report the findings and make the adjustments. ISS diffracted power is down to ~5% this morning. REFSIGNAL was at -2.04V as it was set by me yesterday. Today I have adjusted REFSIGNAL to -2.02V to bring the diff power to ~8.6%. Attached is a past 5 day trend. the spikes, i am told, are likely caused by activations on MC2? (for example)
model restarts logged for Tue 04/Nov/2014
2014_11_04 09:13 h1suspr3
2014_11_04 09:18 h1susbs
2014_11_04 09:18 h1sussr3
2014_11_04 09:20 h1susitmx
2014_11_04 09:22 h1susitmy
2014_11_04 09:24 h1susetmx
2014_11_04 09:25 h1susetmy
2014_11_04 09:41 h1lsc
2014_11_04 09:46 h1broadcast0
2014_11_04 09:46 h1dc0
2014_11_04 09:46 h1fw0
2014_11_04 09:46 h1fw1
2014_11_04 09:46 h1nds0
2014_11_04 09:46 h1nds1
2014_11_04 10:34 h1calex
2014_11_04 10:35 h1caley
2014_11_04 11:12 h1iopoaf0
2014_11_04 11:12 h1pemcs
2014_11_04 11:14 h1oaf
2014_11_04 11:14 h1odcmaster
2014_11_04 11:14 h1tcscs
2014_11_04 12:36 h1broadcast0
2014_11_04 12:36 h1dc0
2014_11_04 12:36 h1fw0
2014_11_04 12:36 h1fw1
2014_11_04 12:36 h1nds0
2014_11_04 12:36 h1nds1
no unexpected restarts. Maintenance Day. Jeff SUS and LSC model work (with associated DAQ restart). Dave CAL work (with associated DAQ restart, plus latest Guardian and Beckhoff EDCU channels)
Greg, Sheila and Dave
Peter Fritschel asked us if we could get a sense of which channels were compressing well in the frame, as part of the decision making of which channels should go into the science frame. Greg wrote a script which calculates the compression rate on a channel by channel basis. To keep the numbers manageable we limited the channels to those with acquisition rates of 1024 or higher.
Sheila suggested a time where the H1 IFO was in its best state to give our most realistic compression rates. The time chosen was 1am PDT Friday 31st October, GPS time 1098777600.
The results are appended as a text file showing 2918 channels (name, acquisition rate, compression ratio).
Also attached is a histogram plot showing the distribution of the compression rates.
Evan, Sheila, Nic, Lisa To answer Peter's questions , we have relocked the DRMI (without arms) on 1f and 3f (10W input power, 27 mW on the BBPD photo-detector). The DRMI was very stable in both cases, here are the good times: Nov 5, 6:00 - 6:15 UTC DRMI locked on 1f, WFS on Nov 5, 6:30 - 6:45 UTC DRMI locked on 3f, WFS on Evan is about to post plots with error signal spectra. It is probably a good idea to make some plots with ground motion/ISI/optical lever signals to "capture" these good times.
These are the corresponding RFPD spectra. The analogous LLO measurement is LLO#15430. LLO's measurement of RF135 seems pretty surprising, since the 3f demodulated spectra appear to be almost entirely noise-dominated above 20 Hz.
What's this 2449.25Hz line that grows over time?
In the attached left, the error signal for PRCL and SRCL grew larger and larger toward the end of the lock.
In the attached right, red, blue and green correspond to the end, middle and the beginning of the lock. The difference in noise floor might be that they were switching from 1f and 3f or vice versa.
Regardless, a line at 2449.25Hz grew larger over time and it was dominating the error signal RMS.
Is this something intentional? Oscillation somewhere? Rogue line?
I am not sure what the 2449.25 Hz line is; there is not a line there that I know of...
In terms of the difference in the noise floor, I can confirm that this comes from the 1f to 3f transition. Keita's green trace was taken from 5:50 PM UTC, blue trace from just after 6:20 PM UTC, and red trace was taken at 6:50 PM UTC. I have attached a dataviewer snap shot showing the LSC PD input matrix of the MICH (2_23), PRCL (3_20), SRCL (4_22) 3f signals around that time. The MICH and PRCL signal transistion at around 6:17 PM UTC, which explains why the blue and red traces in those plots go up. Meanwhile, SRCL transitions a bit later at 6:26 PM UTC, which explains why only the red trace goes up in the noise floor.
According to Dennis the lowest elastic mode of the beamsplitter is expected to be at 2458 Hz (right circular cylindrical without wedge angle, bevels, wire standoff-prisms).
Looking at past data in DQ channels on the ETM suspensions, I tried to estimate the bounce and roll mode frequencies.
I used the top stage V and R degrees of freedom, as well as the oplevs. I used 0.001Hz BW.
I could see the modes in ETMY, but ETMX did not have these modes rung up apparently.
ETMY bounce: 9.730 0.001 Hz
ETMY roll: 13.816 0.001 Hz
This is related to Hugh's log 14774. To elaborate a bit on Hugh's log, I made a measurement with Stage 1 Damped only and HPI isolated. The first plot shows the GND_T240_X , ST1_T240_X and HPI L4C (out of loop witness). There was no coherence with ground below 0.1 Hz but there was significant coherence with HPI L4C. This meant that HPI was somehow introducing excess low-frequency motion.
We then did the same measurement on ETMY and saw no such excess motion. The second pdf shows the corresponding measurement. Stage 1_Y was very coherent with ground_Y. Jim mentioned he had modified the HPI controllers on ETMY as described in Hugh's log, so we decided to try the same on ETMX in X and Y.
This has made a significant difference to the low frequency performance of Stage 1 as shown in the third file. Performance below 0.1 Hz is much closer to ground motion now.
Some more plots of the old vs new isolation filters, per Jeff's request. I dug into the foton file to find numbers to back up what I thought the original design was. The gains of the old and new foton filters are shown in the first image, they show that not much was done to the filter design, just that the gain was reduced. Solid lines are the old design(higher gain, UGF), dashed lines are the current design. Second and third images are the currently installed plant design and a reconstruction of the orignal design (no plots were found from the original design from earlier this year). The solid and dashed orange lines tell most of the story, mostly we just cut the UGF to 2hz, and modified the boost to get more phase margin. No idea why this affect the very low frequency noise, Jeff and Krishna suggested maybe we were re-injecting IPS noise with the higher gain.
Here is another look at the controller with the amplitude scale zoomed out to see the lowest frequencies of the open loop.
J. Warner, K. Venkateswara
We repeated this measurement today and did not see the same results. Sensor correction was off. The attached pdf shows the before (old controller) and after (new low gain UGF controller) data. Very strange. We may have been fooled by different ground motion or perhaps by sensor correction. There is good coherence with ground till ~60 mHz in either controllerconfiguration.
Jim has reverted to the new low gain UGF controller as it should help with ringing of HEPI at 9 Hz.
See the attached for some manipulated data.
There are now pressure signals coming from the End Station VEAs just before the BSCs fluid distribution manifolds. So the pressure before the actuators and the pressure just after the actuators (before and after the distribution manifolds.) See the first attachment--you can see that there is some 6psi pressure drop from the last transducer on the Pump Station Manifold to the Transducer just before the supply distribution manifold at the chamber. This is a distance of some 80 or 90 feet of 1" tube.
The idea is that the Actuators are meant to operate at a consistent pressure drop and having the sensors in the area of operation and where we have tighter temperature regulation would be a better thing. While these epics channels can be conditioned (smoothed, averaged,...) the second attachment shows how much noisier these raw signals would be to produce the differential pressure signal for the servo. I've subtracted the Return Pressure from the Supply to get the Differential; the vertical scales are the same for the two EX signals,and the same for the two EY signals. All plots are in PSI.
Why are they so much noisier? Let me see, maybe the 80 or 90 feet of cable? We do have an at chamber active signal amplifier, don't know the DCC off hand but later.
Anyway, I may be a little reluctant to switch HEPI to these signals. I don't think any one has complained about HEPI because we are running on the direct supply pressure rather than the differential.
As RichM pointed out to me, in the second plot, the lower traces of Output Pressure are in loop and the True Differential plotted above are out of loop. I would expect these situations to reverse whence the servo switches to the latter. Additioinally, the first plot which has the max & mins, show the overall noise on the three channels are really the same at the stations; there is certainly more noise on the EY sensors by something like a factor of 2. But you can see how much quieter the mean is on the servo'd channel.
So, I don't think there is sensor noise issue here to worry about.