J. Kissel

Another data point on the issue of IPC timing causing errors between the LSC model and QUAD models -- Stuart and I added 1 (one) RFM IPC sender to the LSC and 1 (one) RFM PC receiver to each of the ETM models for DARM-sensed, violin mode damping on Tuesday morning (see LHO aLOG 14657). This appears to have increased the ETM model's CPU_METER by ~1 [us], and made no change to the random-time computation time jumps up by as much as ~5-6 [us]. Surprisingly, it *decreased* the LSC model's average compute time by ~ 1 [us], but again also did not affect the timing jumps as high as an extra 7-9 [us].

I attach a 7 day, minute trend. The only discrete jump in the trend is when the models were restarted around 2014-10-28 14:15 UTC (or Tuesday 2014-10-28 07:15 PDT).

I noticed that the DARM Error damping display on the QUAD MEDM Overview screen was showing the incorrect channel information. So I substituted them for the correct channels (H1:SUS-ITMY_L2_DAMP_MODE1_OUTPUT, H1:SUS-ITMY_L2_DAMP_MODE2_OUTPUT etc.) and committed the fixed screen to the userapps svn, as follows:-

/opt/rtcds/userapps/release/sus/common/medm/quad/
M        SUS_CUST_QUAD_OVERVIEW.adl

This will need to be svn'd up at LLO too.

Between approximately 10:07 AM PT and 10:16 AM PT the network upstream of LHO had some routing changes or outage that caused a temporary loss of connectivity to the Internet past PNNL/ESnet.

Bubba, John,

In order to compensate for the cooler weather we have turned on two LVEA heaters at ~ 09:40 local

HC1A  is  set to 15ma (two stages) - it appears that the first stage is open circuit.

HC2b is set to 9ma (one stage).

There will be a minor impact on LVEA temperatures.

At Peter Fritschel's request, I have extracted lists of science and commissioning channels, as a follow-up to the frame rate studies ( see aLOG 14718 ).  I modified my existing script to extract the names (see attached scichannels_script.txt).  As a reminder 'acquire=1' means commissioning only, 'acquire=3' means science and commissioning frames.

The list of science frame channels is 'h1_sci_channels.txt'.  The list of commissioning frame-only channels is 'h1_comm_channels.txt'.  Each list has a channel and its rate.

Kyle Ryan, R. Weiss
Running the ionizer on purge gas air solves the problem of unequal positive and negative
ion currents in the gas being used to discharge the test masses. The oxygen which has
known negative ion states provides the bulk of the negative ions. The ionizer was run for
2 hours with sampled + and - ion currents of 1.5e-9 Amps ( a factor of 100 more in the ion 
stream). Optical HR coating test samples and some VITON pieces were placed in the ion stream
to determine if the chemically reactive oxygen ions and ozone formed in the ionizer do damage. The
optical samples will be sent to Caltech for absorption tests.

The purge air system was turned off at 7:10PM last night.

The 4.5 hour heating test last night on ITMX was successful. The initial thermal lens transient is shown in the attached plot.

The thermal lens forms relatively rapidly in response to the CO2 heating. Then it decays at the same rate when the heating is turned off. Once again, Physics works.

When the offset in the spherical power at t = 0s is accounted for, the thermal lens magnitude is approximately 80 micro-diopters (double-passed) for 680mW of applied CO2 laser power.

Further analysis on the shape and centering of the lens is pending ...

(The noise in the HWS measurement in the last half hour is coming from SUS injections into ITMX).

model restarts logged for Wed 29/Oct/2014
2014_10_29 10:31 h1fw1

unexpected restart of h1fw1

Posting some more details on the parameter changes from the model fitting of H1SR2 discussed in 10124.

Some plots showing measured M3 length to pitch coupling against this model and the original model are also attached. The coherence is pretty poor in this data, so it is difficult to draw concolusions on which model is the better predictor of this coupling.

Parameters  |      units        |         old model       |        H1SR2 fit         |      difference       |      percent difference


 'I1x'   | kgm^2    [   0.0213]    [   0.01994]    [ -0.0013599]    '-6.38%'  

 'I1y'   | kgm^2    [   0.0025]    [ 0.0027219]    [ 0.00022193]    '8.88%'   

 'I1z'   | kgm^2    [   0.0216]    [  0.020356]    [ -0.0012436]    '-5.76%'  

 'm2'    | kg       [    2.983]    [     2.985]    [      0.002]    '0.067%'  

 'I2x'   | kgm^2    [  0.00889]    [ 0.0084199]    [-0.00047015]    '-5.29%'  

 'I2y'   | kgm^2    [  0.00531]    [ 0.0050135]    [-0.00029646]    '-5.58%'  

 'I2z'   | kgm^2    [  0.00635]    [ 0.0064319]    [ 8.1928e-05]    '1.29%'   

 'I3x'   | kgm^2    [  0.00832]    [ 0.0080117]    [-0.00030834]    '-3.71%'  

 'I3y'   | kgm^2    [   0.0054]    [ 0.0051465]    [-0.00025352]    '-4.69%'  

 'I3z'   | kgm^2    [  0.00557]    [ 0.0053901]    [-0.00017987]    '-3.23%'  

 'l1'    |  m       [    0.295]    [   0.30057]    [  0.0055655]    '1.89%'   

 'l2'    |  m       [    0.167]    [   0.17123]    [  0.0042327]    '2.53%'   

 'l3'    |  m       [     0.22]    [   0.22142]    [  0.0014169]    '0.644%'   

 'kc1'   | N/m      [    179.8]    [    182.45]    [     2.6509]    '1.47%'   

 'kc2'   | N/m      [   219.33]    [     212.9]    [    -6.4336]    '-2.93%'  

 'd4'    |  m       [    0.001]    [-0.0006798]    [ -0.0016798]    '-168%'   

 'flex1' |  m       [0.0019381]    [ 0.0019382]    [ 1.0483e-07]    '0.00541%'

Chris, Evan

We have implemented pitch damping by feeding the SR3 oplev back onto M2.

We used the HLTS model susPR3model.mat in NbSVN/aligonoisebudget/trunk/DRMI/L1/TransferFunctions to get a simplified, two-resonance model of the M2 pitch →M3 pitch plant:

• First resonance: f0 = 0.8 Hz, Q = 125
• Second resonance: f0 = 3.6 Hz, Q = 251
• (Also a small resonant wiggle aroung 0.6 Hz, but it doesn't seem to be so important.)

Then we added the following filters to foton:

• zpk([0],[100],1,"n")
• zpk([],[50;50;50],1,"n")
• zpk([0.045+i*3.6;0.045-i*3.6],[],1,"n")
• zpk([0.03;0.7],[0.141421+i*0.141421;0.141421-i*0.141421],1,"n")gain(0.525002)
• ellip("LowPass",4,2,40,15)

In the attached screenshot, you can see the expected OLTF (in foton) and the measured OLTF (in DTT).

Also in the attached screenshot, you can also see some spectra. Blue is no damping, Green is the existing M3 damping, and red is the new M2 damping. Brown is the control signal for the M2 damping. Evidently, amount of suppression is about the same for the two loops.

We suspect that the bump at 2.5 Hz or so (not to be confused with the suspension resonance at 3.6 Hz) is gain peaking in the loop. Some more optimization may be necessary. Additionally, we need to consider how much noise is being injected into the motion of PR3. We tried for a little while, but realized that (a) we need to get the calibration from counts to newton-meters in order to make sense of the control spectrum, and (b) we haven't yet formulated a noise requirement that the oplev loop must meet.

Repeating work just done at LLO (see aLOG 15385 ), I have run some scripts to count the current H1 rates to frame files for commissioning and science frames.  I got copies of the channel lists from the 'daqsvn' SVN server.
The script syntax is in (attached) commrates_script.txt.

acquire=1 got channels only in commissioning frame  (attached h1commrates.txt)
acquire=3 got channels only in science and commissioning frame (attached h1scirates.txt)

I created additional scripts (see attached calc_comm_rates_table_script.txt) to sum things up by sub-system.

See attached h1_comm_rates_table.txt, h1_sci_rates_table.txt.

Science frames use acquire=3, commissioning have acquire=1,3

I put this into a spreadsheet (attached H1FrameRates_2014-10-29.xls) and tabulated for Commissioning and Science Frames (see PDFs)

Of note:
 The pre-compression rate of 21.50 MB/s is resulting in a compressed rate of over 12 MB/s (which includes all the EPICS channels).  If we compare this to the L1 uncompressed rate of 16.91 MB/s, we see that most of the difference (4.6 MB/s) is because the H1 PEM rate is 6.79 MB/s compared to L1's 2.20 MB/s.  At H1, PEM rate is greater than all the ISC data.

As requested by the seismic team,  I ran the script to configure the ETMX ISI to a test configuration at around 1:47:00 in UTC or 18:47:00 in PDT. I am leaving it in this configuration.

I've set up the script co2X_delayed_start.sh to turn on about 650mW of CO2 central heating on ITMX at 12:05AM. It will turn off after 4 hours.

Aidan. Alastair. Greg.

We started heating ITMX with the central heating beam while running the HWSX sensor. We observed the gradient field of the HWS sensor (created from the difference between before and after 1W of heat applied for 100-200s). The sharp edge of the heating pattern was clearly visible in the gradient field.

We iteratively adjusted the upper periscope mirror on TCS CO2X (PICO_F_3) to adjust the alignment to ITMX. As a roughly calibration we measured 42 mm of motion for 7000 counts applied to the picomotors, or with the signs included:

Displacement on ITMX = [-6, -6] micrometers per count on PICO_F_3

I'm not 100% confident that the calibration of the center of the optic is correct. However, the HWS gradient field displayed here is adjusted to the coordinates of the test mass using this morning's RH measurement.

Also, note that we're measuring the position of the CO2 laser beam using the transient thermal lens which provides a strong signal at the edge of the heating beam during the initial stages of heating. The measurements below do not represent the steady-state thermal lens which will look significantly different.

However, the bottom line is that the CO2X central heating beam that was not correctly aligned to the center of the test mass is not much closer to being aligned. We will continue to fine tune this tomorrow.

The plot below shows the iterative alignment of the CO2 heating beam. The first and second panels are the original alignment. The second panel is zoomed in around the HWS measurement. The green circle represents the edge of the test mass. The red circle represents the diameter of the TEM00 mode of the IFO. The blue arrows are the HWS gradient field. The strong arc visible in the bottom left corner is the edge of the CO2 heating beam thermal lens. The PICO motor counts for the upper periscope mirror are shown in the titles for the plots.

Aidan.

I upgraded the HWS code to v1.1.5 on H1HWSMSR. This change saves the centroid data as a MATLAB workspace with GPS time in the filename in the FRAMEARCHIVE directory.

Something about the installation on H1HWSMSR is preventing the centroid data being saved in the nominal GWF file format in v1.1.4 of the code, so the v1.1.5 addition is a work around until we fix that installation issue.

Aidan. Alastair.

Around 10:40AM Alastair and I were looking at the ITMX HWS EPICS channels (spherical power, prism, etc) and noticed them getting very noisy. After some discussion with people in the control room, it turned out that there were some white noise injections going into the ETMX suspension.

We started streaming the image from the HWSX camera to the control room - it's peak intensity was around 1500 counts. We misaligned ITMX by several hundred micro-radians, until the return probe beam disappeared from the HWSX stream. There was a residual beam in the image, with a peak intensity of around 300 counts, that was swinging around. We confirmed this was ETMX by changing the pitch of ETMX from 403 to 360 micro-radians and observing the residual beam disappear.

Once the IFO alignment is settled, we will likely need to adjust the HWS alignment so we don't get any return beams from the ETMs.

Alastair, Aidan.

We tracked down the source of the cross-coupling between the HWSY probe beam and the HWSX sensor. The offending beam was coming from the HWSY BS (we think). By blocking the Y-beam at various points we were able to figure out where it was coupling across the HWSX and we subsequently placed a dump in front of it before that point (between M8 and M9 in the Y-arm optical layout - see the attached photo).

One more thing, I checked the following configurations to look for any other stray beams:

• Viewed HWSX camera with HWSX probe beam OFF and HWSY probe beam ON: no visible signals on the camera
• Viewed HWSY camera with HWSY probe beam OFF and HWSX probe beam ON: no visible signals on the camera

[Jeff K, Stuart A]

Following work yesterday preparing QUAD model updates (see LHO aLOG entry 14645), we convened early this morning to rebuild, install and restart models. 

A detailed log of our activities follows:-

- Bring down the IMC to DOWN state via Guardian (no change to LSC model)
- Bring down QUADs to SAFE state via Guardian
- Bring down SEI to OFFLINE state via Guardian  
- Capture new safe BURT snapshots for h1lsc, h1susetmx, h1susetmy, h1susitmx and h1susitmx
- Made all QUADs
- Installed all QUADs
- Restarted all QUADs
- Svn-up updated QUAD MEDM screens
- Untripped all Watchdogs
- Restore QUAD alignments
- Restore SEIs to FULLY_ISOLATED via Guardian 
- Restore IMC to LOCKED via Guardian
- DAQ process restart at 14:29 (UTC)
- Update other SUS MEDM screens (see LLO aLOG entry 15004) 
- Cleaned errant IPC issues with diag reset on GDS TP screen
- Committed new safe BURT snapshots to svn

Summary of benefits:

This now makes damping of violin, bounce and roll modes possible via the the L2 (PUM) stage of all QUADs using DARM error. Other benefits include: ESD linearization, providing infrastructure for remote ESD activation and deactivation. Also, old Guardian infrastructure has been removed from the model and MEDM screen, with new Guardian embedded mini control-panel replacing them in the QUAD Overview MEDM screen (as well as for other Suspensions too)

This closes-out WP#4915.