40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
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ID Date Author Type Category Subject
26   Mon Oct 29 12:20:15 2007 waldmanConfigurationOMCChanged OMS filters
I changed the OMS configuration so that some of the OMC-SUS LED channels go to a breakout box so that we can input the PDH error signal. After lunch, we will try to lock the cavity with a PDH error signal and digital filters. Then its on to dither locked stuff. Note that this LED business will have to be changed back some day. For now, it should be extremely visible because there are dangling cables and a hack job interface lying around.
27   Mon Oct 29 23:10:05 2007 waldmanConfigurationOMCLost in DAQspace
[Pinkesh, Sam]

In setting up a Digital based control of the hanging OMC, we naively connect the Anti-Imaging filter output to an Anti-Aliasing input. This led to no end of hell. For one thing, we found the 10 kHz 3rd order butterworth at 10 kHz, where it should be based on the install hardware. One wonders in passing whether we want a 10 kHz butter instead of a 15 kHz something else, but I leave that for a later discussion. Much more bothersome is a linear phase shift between output and input that looks like ~180 microseconds. It screams "What the hell am I!?" and none of us could scream back at it with an answer. I believe this will require the Wilson House Ghost Busters to fully remedy on the morrow.
Attachment 1: SS.pdf
Attachment 2: SS.gif
37   Wed Oct 31 09:45:28 2007 waldmanOtherOMCResolution to DAQland saga
[Jay, Sam]

We did a rough accounting for the linear delay this morning and it comes out more or less correct. The 10 kHz 3rd order butterworth AA/AI filter gives ~90 degrees of phase at 6 kHz, or 42 microseconds. Taken together, the two AA and AI filters are worth 80 microseconds. The 1.5 sample digital delay is worth 1.5/32768 = 45 microseconds. The remaining 160 - 125 = 35 microseconds is most likely taken up by the 64 kHz to 32 kHz decimation routine, assuming this isn't accounted for already in the 1.5 sample digital delay.

It remains to be seen whether this phase delay is good enough to lock the laser to the OMC cavity
42   Wed Oct 31 23:55:17 2007 waldmanOtherOMCQPD tests
The 4 QPDs for the OMC have been installed in the 056 at the test setup. All 4 QPDs work and have medm screens located under C2TPT. The breadboard mounted QPDs are not very well centered so their signal is somewhat crappy. But all 4 QPDs definitely see plenty of light. I include light and dark spectra below. QPDs 1-2 are table-mounted and QPD 2 is labeled with a bit of blue tape. QDPs 3-4 are mounted on the OMC. QPD3 is the near field detector and QPD4 is the far field. In other words, QPD3 is closest to the input coupler and QPD4 is farthest.

Included below are some spectra of the QPDs with and without light. For QPDs 1 & 2, the light source is just room lights, while 3&4 have the laser in the nominal OMC configuration with a few mWs as source. The noise at 100 Hz is about 100 microvolts / rtHz. If I recall correctly, the QPDs have 5 kOhm transimpedance (right Rich?) so this is 20 nanoamps / rtHz of current noise at the QPD.
Attachment 1: QPD_SignalSpectrum.pdf
Attachment 2: QPD_SignalSpectrum.gif
43   Thu Nov 1 01:28:04 2007 waldmanOtherOMCFirst digital lock of OMC
[Pinkesh, Sam]

We locked a fiber based NPRO to the suspended OMC tonight using the TPT digital control system. To control the laser frequency, we took the PZT AI output and ran it on a BNC cable down the hallway to the Thorlabs HV box. The Thorlabs is a singled ended unit so we connected the AI positive terminal only and grounded the BNC to the AI shield. We could get a -6 to 1.5 V throw in this method which fed into the 10 k resisotr + 9 V battery at the input of the HV box. The HV out ran to the NPRO PZT fast input.

We derived our error signal from a PDA255 in reflection with a 29.5 MHz PDH lock. The signal feeds into one of the unused Tip/Tilt AA channels and is passed to the PZT LSC drive through the TPT_PDH1 filter bank. In the PZT_LSC filter we put a single pole at 1 Hz which, together with the phase we mentioned the other night (180 degrees at 3 kHz) should allow a 1 kHz-ish loop. In practice, as shown below, we got a 650 Hz UGF with 45 degrees of phase margin and about 6 dB of gain margin.

The Lower figure shows the error point spectrum with 3 settings. REF0 in blue shows lots of gain peaking at 1.5 kHz-ish, just where its expected - the gain was -40. The REF1 has gain of -20 and shows no gain peaking. The current trace in red shows some gain peaking cuz the alignment is better but it also has included a 1^2:20^2 boost which totally crushes the low frequency noise. We should do a better loop sweep after getting the alignment right so we can see how much boost it will really take.

Just for fun, we are leaving it locked overnight and recording the PZT_LSC data for posterity.
Attachment 1: 071101_PZT_firstLoopSweep.pdf
Attachment 2: 071101_PZT_firstLoopSweep.gif
Attachment 3: 071101_OMC_FirstLock_spectra.pdf
Attachment 4: 071101_OMC_FirstLock_spectra.gif
58   Fri Nov 2 12:18:47 2007 waldmanSummaryOMCLocked OMC with DCPD
[Rich, Sam]

We locked the OMC and look at the signal on the DCPD. Plots included.
Attachment 1: 071102_OMC_LockedDCPD.gif
Attachment 2: 071102_OMC_LockedDCPD.pdf
59   Sat Nov 3 16:20:43 2007 waldmanSummaryOMCA good day's work

I followed up yesterday's test of the PZT with a whole mess of characterizations of the PZT control and finished the day by locking the OMC with a PZT dither lock and a 600 Hz loop. I haven't analyzed any of the data yet, so its not calibrated in physical units and etc. etc. etc. Since a lot of the sweeps below are of a "drive the PZT, look at the PDH signal" nature, a proper analysis will require taking out the loop and calibrating the signals, which alas, I haven't done. Nonetheless, I include all the plots because they are pretty. The files included below are:

• DitherLock_sweep: Sweep of the IN2/IN1 for the dither lock error point showing 600 Hz UGF
• HiResPZTDither_sweep: Sweep of the PZT dither input compared to the PDH error signal. I restarted the front end before the sweep was finished accounting for the blip.
• HiResPZTDither_sweep2: Finish of the PZT dither sweep

More will be posted later.
Attachment 1: 071103_DitherLock_sweep.png
Attachment 2: 071103_DitherLock_sweep.pdf
Attachment 3: 071103_HiResPZTDither_sweep.png
Attachment 4: 071103_HiResPZTDither_sweep.pdf
Attachment 5: 071103_HiResPZTDither_sweep2.png
Attachment 6: 071103_HiResPZTDither_sweep2.pdf
60   Sun Nov 4 23:22:50 2007 waldmanUpdateOMCOMC PZT and driver response functions
I wrote a big long elog and then my browser hung up, so you get a less detailed entry. I used Pinkesh's calibration of the PZT (0.9 V/nm) to calibrate the PDH error signal, then took the following data on the PZT and PZT driver response functions.:

• FIgure 1: PZT dither path. Most of the features in this plot are understood: There is a 2kHz high pass filter in the PZT drive which is otherwise flat. The resonance features above 5 kHz are believed to be the tombstones. I don't understand the extra motion from 1-2 kHz.
• Figure 2: PZT dither path zoom in. Since I want to dither the PZT to get an error signal, it helps to know where to dither. The ADC Anti-aliasing filter is a 3rd order butterworth at 10 kHz, so I looked for nice flat places below 10 KHz and settled on 8 kHz as relatively harmless.
• Figure 3: PZT LSC path. This path has got a 1^2:10^2 de-whitening stage in the hardware which hasn't been digitally compensated for. You can see its effect between 10 and 40 Hz. The LSC path also has a 160 Hz low path which is visible causing a 1/f between 200 and 500 Hz. I have no idea what the 1 kHz resonant feature is, though I am inclined to point to the PDH loop since that is pretty close to the UGF and there is much gain peaking at that frequency.
Attachment 1: 071103DitherShape.png
Attachment 2: 071103DitherZoom.png
Attachment 3: 071103LSCShape.png
Attachment 4: 071103DitherShape.pdf
Attachment 5: 071103DitherZoom.pdf
Attachment 6: 071103LSCShape.pdf
Attachment 7: 071103LoopShape.pdf
63   Mon Nov 5 14:44:39 2007 waldmanUpdateOMCPZT response functions and De-whitening
The PZT has two control paths: a DC coupled path with gain of 20, range of 0 to 300 V, and a pair of 1:10 whitening filters, and an AC path capacitively coupled to the PZT via a 0.1 uF cap through a 2nd order, 2 kHz high pass filter. There are two monitors for the PZT, a DC monitor which sniffs the DC directly with a gain of 0.02 and one which sniffs the dither input with a gain of 10.

There are two plots included below. The first measures the transfer function of the AC monitor / AC drive. It shows the expected 2 kHz 2d order filter and an AC gain of 100 dB, which seems a bit high but may be because of a filter I am forgetting. The high frequency rolloff is the AA and AI filters kicking in which are 3rd order butters at 10 kHz.

The second plot is the DC path. The two traces show the transfer function of DC monitor / DC drive with and with an Anti-dewhitening filter engaged in the DC drive. I fit the antidewhite using a least squares routine in matlab constrained to match 2 poles, 2 zeros, and a delay to the measured complex filter response. The resulting filter is (1.21, 0.72) : (12.61, 8.67) and the delay was f_pi = 912 Hz. The delay is a bit lower than expected for the f_pi = 3 kHz delay of the AA, AI, decimate combination, but not totally unreasonable. Without the delay, the filter is (1.3, 0.7) : (8.2, 13.2) - basically the same - so I use the results of the fit with delay. As you can see, the response of the combined digital AntiDW, analog DW path is flat to +/- 0.3 dB and +/- 3 degrees of phase.

Note the -44 dB of DC mon / DC drive is because the DC mon is calibrated in PZT Volts so the TF is PZT Volts / DAC cts. To calculate this value: there are (20 DAC V / 65536 DAC cts)* ( 20 PZT V / 1 DAC V) = -44.2 dB. Perfect!

I measured the high frequency response of the loop DC monitor / DC drive to be flat.
Attachment 1: 07110_DithertoVmonAC_sweep2-0.png
Attachment 2: 071105_LSCtoVmonDC_sweep4-0.png
Attachment 3: 07110_DithertoVmonAC_sweep2.pdf
Attachment 4: 071105_LSCtoVmonDC_sweep4.pdf
79   Wed Nov 7 14:01:31 2007 waldmanOmnistructureOMCFrequency and Intensity noise
One of the biggest problems I had using the PZT to lock was excessive noise. I did a little noise hunting and found that the problem was the cable running from the rack to the laser fast input. As a reminder, the laser has a 4 MHz / volt fast input. We require about 300 MHz to go one FSR, so there is a Thorlabs HV box between at the NPRO fast input which takes 0-10 V -> 0-150 V. The 150 V HV range is worth about 600 MHz of NPRO frequency.

OLD SETUP: Single side of DAC differential (10 Vpp) -> 9V in series with 10 kOhm -> 10 kOhm input impedance of Thorlabs HV -> NPRO

We used the single side of the DAC differential because we didn't have a differential receiver. This turned out to be a bad idea because the cable picks up every 60 Hz harmonic known to man kind.

NEW SETUP: Digital conditioning -> DAC differential (digitally limited to 0 - 1 V) -> SR560 in A-B mode gain 10 (0 - 10 V output)-> Thorlabs HV -> NPRO.

This has almost no 60 Hz noise and works much, much better. Moral of the story, ALWAYS USE DIFFERENTIAL SIGNALS DIFFERENTIALLY !

Note that I may be saturating the SR560 with 10 V output, Its spec'd for 10 Vpp output with 1 VDC max input. I don't know whether or not it can push 10 V out....
86   Fri Nov 9 00:01:24 2007 waldmanOmnistructureOMCOMC mechanical resonances (Tap tap tappy tap)
[Pinkesh, Aidan, Sam]

We did a tap-tap-tappy-tap test of the OMC to try to find its resonances. We looked at some combination of the PDH error signal and the DCPD signal in a couple of different noise configurations. The data included below shows tapping of the major tombstone objects as well the breadboard. I don't see any strong evidence of resonances below the very sharp resonance at 1300 Hz (which I interpret as the diving board mode of the breadboard). If I get free, I 'll post some plots of the different breadboard resonances you can excite by tapping in different places.

(The "normalized" tapping response is abs(tap - reference)./reference.)
Attachment 1: Fig1.png
Attachment 2: Fig2.png
Attachment 3: Fig4.png
Attachment 4: Fig2.pdf
Attachment 5: Fig1.pdf
Attachment 6: Fig4.pdf
Attachment 7: ResonanceData.zip
179   Fri Dec 7 11:33:24 2007 waldmanOmnistructureOMCPZT wiring
The 2 pin LEMO connector has got an unmarked pin and a pin marked by a white half-circle.
The unmarked pin is connected to the side of the PZT attached to the mirror.
The marked pin is connected to the side of the PZT attached to the tombstone.
206   Thu Dec 20 19:05:34 2007 waldmanHowToOMCHOWTO build front ends
For instance, to build the TPT front end code.

• go to /cvs/cds/advLIGO on the TPT machine
• do make clean-tpt tpt install-tpt
• do rm /cvs/cds/caltech/chans/daq/C2TPT.ini (this step is needed because the DAQ install code isn't quite right at the time of this writing.
• do make install-daq-tpt
• run starttpt to restart the tpt computer.

Enjoy.
207   Thu Dec 20 19:10:03 2007 waldmanUpdateOMCStressful reattachment of heater
Photos may follow eventually, but for now here's the rundown. I scraped the heater clean of the thermal epoxy using a clean razor blade. Then I stuffed a small piece of lint free cloth in the OTAS bore and wrapped the OMC in tin foil. With a vacuum sucking directly from the face of the OTAS, I gently scraped the glue off the OTAS aluminum. I wiped both the OTAS and the heater down with an isoproponal soaked lint-free cloth. I put a thin sheen of VacSeal on the face of the heater, wiping off the excess from the edges with a cloth. Then I clamped the heater to the OTAS using 2" c-clamps from the tombstone back to the heater front, making sure the alignment of the OTAS was correct (connector on the absolute bottom, concentric with the OTAS outer diameter). I added a second clamp, then beaded the outside of the joint with a little bit extra VacSeal, just for kicks. I'll leave it covered at least overnight, and maybe for a day or two.

sam
14193   Wed Sep 5 10:59:23 2018 wgautamUpdateCDSCDS status update

Rolf came by today morning. For now, we've restarted the FE machine and the expansion chassis (note that the correct order in which to do this is: turn off computer--->turn off expansion chassis--->turn on expansion chassis--->turn on computer). The debugging measures Rolf suggested are (i) to replace the old generation ADC card in the expansion chassis which has a red indicator light always on and (ii) to replace the PCIe fiber (2010 make) running from the c1lsc front-end machine in 1X6 to the expansion chassis in 1Y3, as the manufacturer has suggested that pre-2012 versions of the fiber are prone to failure. We will do these opportunistically and see if there is any improvement in the situation.

Another tip from Rolf: if the c1lsc FE is responsive but the models have crashed, then doing sudo reboot by ssh-ing into c1lsc should suffice* (i.e. it shouldn't take down the models on the other vertex FEs, although if the FE is unresponsive and you hard reboot it, this may still be a problem). I'll modify I've modified the c1lsc reboot script accordingly.

* Seems like this can still lead to the other vertex FEs crashing, so I'm leaving the reboot script as is (so all vertex machines are softly rebooted when c1lsc models crash).

 Quote: c1lsc crashed again. I've contacted Rolf/JHanks for help since I'm out of ideas on what can be done to fix this problem.
14816   Mon Jul 29 19:08:55 2019 yehonathanUpdateLoss MeasurementReviving loss measurement by reflection

1. X arm is totally misaligned in order to measure the Y arm loss using the reflection method. Each measurement round consists of measuring the reflected power when the Y arm is aligned and when it is misaligned.

2. The measurement script used is /scripts/lossmap_scripts/armLoss/measureArmLoss.py. It generates a log file in the /logs folder specifying the alignment and misalignment times.

3. The data extraction script dlData.py processes the raw data in the log file and creates a hdf5 file in the /Data folder conataining the data of the measurement it self.

4. dlData.py labels the the aligned and misaligned datas incorrectly when the number of measurement is odd. I use only even number of measurements then.

5. In order to clip the chaotic transition between the aligned and misaligned states I use tDur attribute smaller than the actual sleep time used in the measurement script itself.

6. plotData.py (written by Gautam) and AnalyzeLossData.ipynb (written by me) can be used to calculate the loss and to plot some analyses (see https://nodus.ligo.caltech.edu:8081/40m/14568). They give roughly the same answer. The descripancy can be explained by the different modulation and ITM transmissions used.

7. I take a measurement of 8 repeatitions. I plot the measured reflected power alternating between the aligned and misaligned states.

I find that the reflected power is repeatable to within 1%.

This is consistent with the transmission data plotted here which is also repeatable to within 1%.

8. I take an overnight measurement of 100 repeatitions.

14827   Mon Aug 5 14:47:36 2019 yehonathanUpdateLoss Measurement

Summary:

I analyze the 100 reps loss measurement of the Y arm using the AnalyzeLossData.ipynb notebook.

The mean of the measured loss is ~ 100ppm and the variation between the repititions is ~ 27%.

In Detail

In the real measurement the misaligned and locked states are repeatedly switched between each other. I plot the misaligned and locked PD readings seperately over time.

There seems to be a drift that is correlated between the two readings. This is probably a drift in the power after the MC2. To verify, I plot the ratio between those readings and find no apparent drift:

The variation in the ratio is less than 1%. The loss figure, computed to be 1 minus this ratio times a big number, give a much worse variation. I plot the histogram of the loss figure at each repitition (excluding extremely bad measurements):

The mean is ~ 100ppm. And the variation is ~ 27%.

Draft   Mon Aug 5 16:28:41 2019 yehonathanUpdateLoss Measurementwhat is going on with the loss measurements ?

We hypothesize that the systematic error in the loss measurement can come from the fact that the requirement on the alignment of the cavity mirrors is not stringent enough.

We repeat the loss measurement with 50 measurements. This time we change the thresholds for the error signals of the dither-align in the measureArmLoss.py file from 0.5 to 0.3.

We repeat the analysis done before:

We plot the reflected power of the two states on top of each other:

This  time it appears there was no drift. The histogram of the loss measurement:

The mean is 104ppm and the variation is 27%.

What I notice this time is that the PD readings in the aligned and misaligned states are anti-correlated. This is also true in the previous run (where there was drift) when looking in the short time scales. I plot several time series to demonstrate:

I wonder what can cause this behaviour.

14830   Mon Aug 5 17:36:04 2019 yehonathanUpdateLoss Measurement

We check for unexpected drifts in the PD reading (clipping and such). We put a pickoff mirror where the PD used to be and place the PD at the edge of the table such that the beam is focused on it (see attachment).

The arms are completley misaligned. We note the time of start of measurement to be 1249086917.

Attachment 1: 20190805_171511.jpg
14831   Tue Aug 6 14:12:02 2019 yehonathanUpdateComputersmaking rossa great again

cdsutils is not working on rossa.

Import cdsutils produces this error:

In [2]: import cdsutils
---------------------------------------------------------------------------
OSError                                   Traceback (most recent call last)
<ipython-input-2-949babce8459> in <module>()
----> 1 import cdsutils

/ligo/apps/linux-x86_64/cdsutils-480/lib/python2.7/site-packages/cdsutils/__init__.py in <module>()
53
54 try:
---> 55     import awg
56 except ImportError:
57     pass

/ligo/apps/linux-x86_64/cdsutils-480/lib/python2.7/site-packages/cdsutils/awg.py in <module>()
30 """
31
---> 32 import sys, numpy, awgbase
33 from time import sleep

/ligo/apps/linux-x86_64/cdsutils-480/lib/python2.7/site-packages/cdsutils/awgbase.py in <module>()
17 libawg = CDLL('libawg.so')
18 libtestpoint = CDLL('libtestpoint.so')
---> 19 libSIStr = CDLL('libSIStr.so')
20
21 ####

/ligo/apps/anaconda/lib/python2.7/ctypes/__init__.pyc in __init__(self, name, mode, handle, use_errno, use_last_error)
364
365         if handle is None:
--> 366             self._handle = _dlopen(self._name, mode)
367         else:
368             self._handle = handle

OSError: libSIStr.so: cannot open shared object file: No such file or directory

14834   Tue Aug 6 16:44:50 2019 yehonathanUpdateLoss Measurement

I grab 2 hours of the PD measurements using dlData_simple.ipynb in the misaligned state.

I get pretty much a normally distributed reading without drifts (Attachements 1 and 2).

The error in the reading is ~ 0.5%.

I am pretty sure this amount of noise is enough to explain the big noise in the Loss figure measurement.

The reason is that the loss formula is #(1-P_Locked/P_Misaligned+T1)-T2) where T1 and T2 are the transmissions of the ITM and ETM.

The average of the ratio P_Locked/P_Misaligned is ~ 1.01 for a loss figure of ~ 100ppm.

The standard deviation of the ratio is ~ 1% which is also the standard deviation of the expression in the brackets.

The average of this experssion however is ~ 0.01.

The reduction of the mean amplifies the error in the loss measurments by a factor of a few 10s!

Attachment 1: figure_1.png
Attachment 2: figure_1-1.png
15116   Fri Jan 10 19:48:46 2020 yehonathanUpdatePSLAssembly underway for c1psl upgrade

{Yehonathan, Jon}

I finished pre-wiring the PSL chassis. I mounted the Acromags on the DIN rails and labeled them. I checked that they are powered up with the right voltage +24V and that the LEDs behave as expected.

Attachment 1: 20200110_194429.jpg
Attachment 2: 20200110_194516_HDR.jpg
15118   Mon Jan 13 16:05:18 2020 yehonathanUpdatePSLAssembly underway for c1psl upgrade

{Yehonathan, Jon}

I configured the Acromag channels according to the Slow Controls Wiki page.

We started testing the channels. Almost at the beginning we notice that the BIO channels are inverted. High voltage when 0. 0 Voltage when 1. We checked several things:

1. We checked the configuration of the BIOs in the windows machine but nothing pointed to the problem.

2. We isolated one of the BIOs from the DIN rail but the behavior persisted.

3. We checked that the voltages that go into the Acromags are correct.

The next step is to power up an isolated Acromag directly from the power supply. This will tell us if the problem is in the chassis or the EPICs DB.

15120   Tue Jan 14 17:16:43 2020 yehonathanUpdatePSLAssembly underway for c1psl upgrade

{Yehonathan, Jon}

I isolated a BIO Acromag completely from the chassis and powered it up. The inverted behavior persisted.

Turns out this is normal behavior for the XT1111 model.

For digital outputs, one should XT1121. XT1111 should be used for digital inputs.

Slow machines Wiki page was updated along with other pieces of information.

I replaced the XT1111 Acromags with XT1121 and did some rewiring since the XT1121 cannot get the excitation voltage from the DIN rail.

I added an XT1111 Acromag for the single digital input we have in this system.

15262   Tue Mar 10 14:30:16 2020 yehonathanUpdateSUS

ETMX was grossly misaligned.

I re-aligned it and the X arm now locks.

7:00PM with Koji

Both the alignment of the X and Y arms was recovered.

~>z avg 10 C1:LSC-TRX_OUT C1:LSC-TRY_OUT C1:LSC-TRX_OUT 0.9914034307003021 C1:LSC-TRY_OUT 0.9690877735614777

We are running ass for the X arm to recover the X arm alignment.

Meanwhile, i want to block the Y arm trans PD (Thorlabs). To do it, the PD<->QPD thresholds were changed from 5.0/3.0 to 0.5/0.3.

Attachment 1: Screenshot_from_2020-03-10_19-02-31.png
15263   Tue Mar 10 19:58:16 2020 yehonathanUpdateSUS

I returned the triggering threshold to normal values (5/3).

 Meanwhile, i want to block the Y arm trans PD (Thorlabs). To do it, the PD<->QPD thresholds were changed from 5.0/3.0 to 0.5/0.3.
15614   Tue Oct 6 07:37:20 2020 yehonathanUpdateWikiNew TIS measurements of 40m Optics

LiYuan has kindly done some Total Integrating Sphere (TIS) measurements on ITMU01 and ITMU02. A summary of the measurement is attached. I uploaded the measurements and some analysis script to nodus at /home/export/home/40m_TIS. I created a Wiki page for the measurements and linked to it from the core optics page.

These TIS measurements look very similar to the TIS of the LIGO optics. Further analysis shows that the scatter loss is 10+/-1.7 ppm for ITMU01 and 8.6+/-0.4 ppm for ITMU02.

In this calculation, a gaussian beam the same size bouncing off the 40m ITMs is assumed to scatter from the mirrors. The error is calculated by moving the beam around randomly with STD of 1mm.

In LiYuan's setup, TIS is measured for scattering angles between 1 and 75 degrees. If we go further and assume that the scatter is Lambertian we can extrapolate that the total loss is 10.9+/-1.9 ppm for ITMU01 and 9.2+/-0.5 ppm for ITMU02.

These measurements complete the loss budget nicely since with the 6ppm loss predicted from the phase maps, the total loss in the arm cavities would be 6+10+10=26ppm which is very close to the 28ppm loss that was measured after the arm cavity optics were cleaned.

Attachment 1: ITMU_sn01-02_tis_1.pdf
15788   Tue Feb 2 17:09:17 2021 yehonathanUpdateBHDSOS assembly

I set up a working area on the table next to the south flow bench (see attachment). I also brought in a rolling table for some extra space.

I covered all the working surfaces with a foil from the big roll between 1x3 and 1x4.

I took the SOSs, SOS parts and the OSEMS from the MC2 table to the working area.

I cleaned some LN Allen keys with isopropanol and put them on the working table, please don't take them.

Attachment 1: 20210202_165501.jpg
Attachment 2: 20210202_162452.jpg
15816   Thu Feb 18 15:15:12 2021 yehonathanUpdateSUSOSEM testing for SOSs

I am setting up a testing rig for the OSEMs we recently obtained. I found the schematic for the OSEM assembly from which the pin assignment can be read.

I connected the OSEM's pin plate to a female DB15 on a breakout board. I find the pin assignment (attachment 1, sorry for the image quality) to be:

 1 PD Cathode 2 LED Anode 3 Coil end 4 PD Anode 5 LED Cathode 6 Coil Start

There are several things that need to be done for each OSEM.

1. Measuring inductance of the coils. I checked that the measurement wires don't add any measurable inductance.

2. Check that the PDs and LEDs are alive (e.g. check forward voltage drop with fluke)

3. Energize the LED and PD.

4. Check PD DC level. For this, I might need the satellite box amplifier.

5. Check LED spot position on the PD.

6. Re-engrave OSEM S/N if needed.

 OSEM # Coil Inductance (mH) Coil resistance (ohm) PD forward voltage (V) LED forward voltage (V) 280 2.87 14.1 0.63 1.1

I still need to figure a sensible scheme for points 3-5.

Attachment 1: OSEM_Pin_Plate.png
15837   Wed Feb 24 10:09:16 2021 yehonathanUpdateSUSOSEM testing for SOSs

Yes, my phone camera mirrored the image. Sorry for the confusion.

 Quote: I can't obtain a consistent view between the existing drawings/photographs and your pin assignment. Please review the pin assignment again to check if yours is correct. Looking from the back side and the wires are going down, the left bottom pin is "Coil Start" and the upper right adjacent pin is "Coil End". (See attachment) So in your picture 1 should be the coil start and 4 should be the coil end, but they are not according to your table.

16062   Wed Apr 21 11:09:57 2021 yehonathanUpdatePSLLaser amplifier

I went to the TCS lab to take a look at the chillers lying around. I spotted two chillers:

1. Thermoflex1400 (attachment 1,2). Spec sheet.

2. Polyscience Recirculator 6000 series (attachment 3,4). Manual.

The Thermoflex has various communication ports. The Recirculator doesn't have any communication ports, but it is connected to a flow meter with what seems to be an electronic readout (attachment 5). Manual.

Both chillers have similar capacity ~ 4 gallons/minute. Thermoflex has 2 times more reservoir capacity than the Recirculator.

None of them seem to be Bechkoff-ready.

I guess we can have interlock code handling mixed signals Beckhoff+Non beckhoffs?

Attachment 1: 20210420_171606.jpg
Attachment 2: 20210420_171621.jpg
Attachment 3: 20210420_171611.jpg
Attachment 4: 20210420_171629.jpg
Attachment 5: 20210420_171702.jpg
16253   Wed Jul 21 18:08:35 2021 yehonathanUpdateLoss MeasurementLoss measurement

{Gautam, Yehonathan, Anchal, Paco}

We prepared for the loss measurement using DC reflection method. We did the following changes:

1. REFL55_Q was disconnected and replaced with MC_T cable coming from the PD on the MC2 table. The cable has a red tag on it. Consequently we lost the AS beam. We realigned the optics and regained arm locks. The spot on the AS QPD had to be corrected.

2. We tried using AS55 as the PD for the DC measurement but we got ratios of ~ 0.97 which implies losses of more than 100 ppm. We decided to go with the traditional PD520 used for these measurements in the past.

3. We placed the PD520 used for loss measurements in front of the AS55 PD and optimized its position.

4. AS110 cable was disconnected from the PD and connected to PD520 to be used as the loss measurement cable.

5. In 1Y2 rack, AS110 PD cable was disconnected, REFL55_I was disconnected and AS110 cable was connected to REFL55_I channel.

So for the test, the MC transmission was measured at REFL55_Q and the AS DC was measured at REFL55_I.

We used the scripts/lossmap_scripts/armLoss/measArmLoss.py script. Note that this script assumes that you begin with the arm locked.

We are leaving the IFO in the configuration described above overnight and we plan to measure the XARM loss early AM. After which we shall restore the affected electrical and optical paths.

We ran the /scripts/lossmap_scripts/armLoss/measureArmLoss.py script in pianosa with 25 repetitions and a 30 s "duty cycle" (wait time) for the Y arm. Preliminary results give an estimated individual arm loss of ~ 30 ppm (on both X/Y arms) but we will provide a better estimate with this measurement.

16371   Fri Oct 1 14:25:27 2021 yehonathanSummarySUSPRM and BS Angular Actuation transfer function magnitude measurements

{Paco, Yehonathan, Hang}

We measured the sensing PRMI sensing matrix. Attachment 1 shows the results, the magnitude of the response is not calibrated. The orthogonality between PRCL and MICH is still bad (see previous measurement for reference).

Hang suggested that since MICH actuation with BS and PRM is not trivial (0.5*BS - 0.34*PRM) and since PRCL is so sensitive to PRM movement there might be a leakage to PRCL when we are actuating on MICH. So there may be a room to tune the PRM coefficient in the MICH output matrix.

Attachment 2 shows the sensing matrix after we changed the MICH->PRM coefficient in the OSC output matrix to -0.1.

It seems like it made things a little bit better but not much and also there is a huge uncertainty in the MICH sensing.

Attachment 1: MICH_PRM_-0.34.png
Attachment 2: MICH_PRM_-0.1.png
16779   Thu Apr 14 11:52:57 2022 yehonathanSummaryBHDPart IIa of BHR upgrade - POY11 debugging

{JC, Paco, Yehonathan, Ian}

POY lens was moved to infront of the POY steering mirror to make the POU beam focused on the POY11 RFPD. We measured the DC output with an oscilloscope and optimized it with the steering mirrors. We get ~ 16.5mV.

The new lens position blocked the BS OpLev ingoing beam, so we repositioned the OpLev mirrors to make the beam path not hit the lens.

We went to the control room to observe the PDH signal. We observed a series of PDF osscillation and then the signal died infront of our eyes! There is just noise.

We go and check the +/-15V powering the RFPD and we find that the V- is ~ 14V which is good but the V+ was ~ 2.7V which is not.

We went to the PD interface and measure the POY11 output oltages using a breakout board and got the same result.

The PD interface was taken out for inspection. All the OP27 on channel 3 were replaced with new ICs (without need turns out)...

The PD interface card turned out to be OK. What happened is that one of the Kepcos in the RF rack died because its fan crumbled as seen in Attachment #2 (could this be the source of burning smell?). In response, the rack was drawing from the other Kepco (connected in parallel) way too much current  (4A) and the current limiter dropped its voltage from 15V to 2.7V.

The Kepco pair was removed and replaced with a single Sorensen. The POY PDH signal was restored (see attachment).

Attachment 1: Screenshot_2022-04-14_15-53-39.png
Attachment 2: PXL_20220414_220616875.jpg
16799   Thu Apr 21 18:18:42 2022 yehonathanUpdateBHDPOX Alignment

{Yehonathan, Paco}

BS, ITMX and ETMX were aligned to get flashing in the X arm.

I aligned the POX beam on the ITMX table using a mixture of the old POP and POX optics. The beam was stirred to the POX11 RFPD. We measure the DC power using a scope but we see nothing. We went and saw that the POX11 cable was not connected to RF rack so we connected it along with some other RFPD cables.

We return but there is still no DC. We ndscope C1:LSC-POX11_I_ERR_DQ C1:LSC-POX11_Q_ERR_DQ and maximize the signal (attachment). The readout is very weak though. It should be as strong as POY which we already observed to have good SNR.

We also noticed that the one of the beam dumps for the POX RFPD is not glued and easily falls down.

Attachment 1: POX11_alignment.png
17041   Thu Jul 28 13:09:28 2022 yehonathanUpdateBHDMode matching considerations

The LO beam was found to have a power of 60uW, 10% of the power expected. We are pretty sure about the expectation because the AS beam has a power of 300uW, roughly the expected power. Additionally, the visibility of the MICH fringes in the BHDR is 40%.

If the mode-matching is perfect then we expect the visibility to be $\text{VIS}=\frac{I_\text{max}-I_\text{min}}{I_\text{max}+I_\text{min}}=\frac{2\sqrt{I_\text{LO}I_\text{AS}}}{I_\text{LO}+I_\text{AS}}=\frac{2\sqrt{300\cdot 60}}{300+600}$

which is roughly 74.5%.

If there is some mode-mismatch one can show that the visibility is $\text{VIS}=\frac{2\sqrt{M}\sqrt{I_\text{LO}I_\text{AS}}}{I_\text{LO}+I_\text{AS}}$, where $M=\left|\frac{\int \left(E_\text{LO}^\star E_\text{AS} \right)\mathrm{d}x \mathrm{d}y}{\sqrt{I_\text{LO}I_\text{AS}}}\right|^2$ is the mode-mismatch.

Using Finesse model I calculated \sqrt(M)=0.93 in the MICH configuration so the expected visibility is around 70%, far away from the observed 40%. To explain the observed visibility the mode mismatch would have to be ~ 30% which is very unlikely.

So it could either be a ghost beam or that the LO beam is clipped so badly that it also degrades its phase front (and therefore the mode-matching). The fact that we see fringes on the LO beam might suggest knife edge clipping on one of the auxiliary optics in the BS chamber.

14825   Fri Aug 2 17:07:33 2019 yehonathan, gautamUpdateLoss Measurement

We run a loss measurement on the Y arm with 50 repetitions.

12825   Mon Feb 13 17:19:41 2017 yinziConfiguration configuring ethernet for raspberry pi

Gautam and I were able to get the Raspberry Pi up and running today, including being able to ssh into it from the control room.

Below are some details about the setup/procedure that might be helpful to anyone trying to establish Ethernet connection for a new RPi, or a new operating system/SD card.

Here is the physical setup:

The changes that need to be made for a new Raspbian OS in order to communicate with it over ssh are as follows, with links to tutorials on how to do them:

3. Enable ssh server: http://www.instructables.com/id/Use-ssh-to-talk-with-your-Raspberry-Pi/

The specific addresses for the RPi we set up today are:

Gateway/Routers/Domain Name Servers: 192.168.113.2

GV: I looked through /etc/var/bind/martian.hosts on chiara and decided to recycle the IP address for Domenica.martian as no RPis are plugged in right now... I'm also removing some of the attachments that seem to have been uploaded multiple times.

14205   Fri Sep 21 09:59:09 2018 yukiConfigurationASCY end table upgrade plan

[Yuki, Gautam]

Attachments #1 is the current setup of AUX Y Green locking and it has to be improved because:

• current efficiency of mode matching is about 50%
• current setup doesn't separate the degrees of freedom of TEM01 with PZT mirrors (the difference of gouy phase between PZT mirrors should be around 90 deg)
• we want to remotely control PZT mirrors for alignment
(Attachments #2 and #3)

One of the example for improvement is just adding a new lens (f=10cm) soon after the doubling crystal. That will make mode matching better (100%) and also make separation better (85 deg) (Attachments #4 and #5). I'm checking whether we have the lens and there is space to set it. And I will measure current power of transmitted main laser in order to confirm the improvement of alignment.

I am considering what component is needed.

Reference:

Attachment 1: Pic_CurrentSetup_AUXYgreen.jpeg
Attachment 2: ModeMatchingSolution_Current.pdf
Attachment 3: ModeMatchingSolution_Current_Magnified.pdf
Attachment 4: ModeMatchingSolution_Optimized.pdf
Attachment 5: ModeMatchingSolution_Optimized_Magnified.pdf
14211   Sun Sep 23 17:38:48 2018 yukiUpdateASCAlignment of AUX Y end green beam was recovered

[ Yuki, Koji, Gautam ]

An alignment of AUX Y end green beam was bad. With Koji and Gautam's advice, it was recovered on Friday. The maximum value of TRY was about 0.5.

14212   Sun Sep 23 19:32:23 2018 yukiConfigurationASCY end table upgrade plan

[ Yuki, Gautam ]

The setup I designed before has abrupt gouy phase shift between two steering mirrors which makes alignment much sensitive. So I designed a new one (Attached #1, #2 and #3). It improves the slope of gouy phase and the difference between steering mirrors is about 100 deg. To install this, we need new lenses: f=100mm, f=200mm, f=-250mm which have 532nm coating. If this setup is OK, I will order them.

There may be a problem: One lens should be put soon after dichroic mirror, but there is little room for fix it. (Attached #4, It will be put where the pedestal is.)  Tomorrow we will check this problem again.

And another problem; one steering mirror on the corner of the box is not easy to access. (Attached #5) I have to design a new seup with considering this problem.

 Quote: One of the example for improvement is just adding a new lens (f=10cm) soon after the doubling crystal. That will make mode matching better (100%) and also make separation better (85 deg) (Attachments #4 and #5). I'm checking whether we have the lens and there is space to set it. And I will measure current power of transmitted main laser in order to confirm the improvement of alignment.

Attachment 1: Pic_NewSetup0923_AUXYgreen.jpeg
Attachment 2: ModeMatchingSolution_Result.pdf
Attachment 3: ModeMatchingSolution_Magnified_0923.jpg
Attachment 4: pic0923_1.jpg
Attachment 5: pic0923_2.jpg
14214   Mon Sep 24 11:09:05 2018 yukiConfigurationASCY end table upgrade plan

[ Yuki, Steve ]

With Steve's help, we checked a new lens can be set soon after dichroic mirror.

 Quote: There may be a problem: One lens should be put soon after dichroic mirror, but there is little room for fix it. (Attached #4, It will be put where the pedestal is.)  Tomorrow we will check this problem again.
Attachment 1: pic0924_1.jpg
14216   Tue Sep 25 18:08:50 2018 yukiConfigurationASCY end table upgrade plan

[ Yuki, Gautam ]

We want to remotely control steeing PZT mirrors so its driver is needed. We already have a PZT driver board (D980323-C) and the output voltage is expected to be verified to be in the range 0-100 V DC for input voltages in the range -10 to 10 V DC.
Then I checked to make sure ir perform as we expected. The input signal was supplied using voltage calibrator and the output was monitored using a multimeter.
But it didn't perform well. Some tuning of voltage bias seemed to be needed. I will calculate its transfer function by simulation and check the performance again tommorow. And I found one solder was off so it needs fixing.

Reference:
diagram --> elog 8932

Plan of Action:

• Check PZT driver performs as we expected
• Also check cable, high voltage, PZT mirrors, anti-imaging board
• Obtain calibration factor of PZT mirrors using QPD
• Measure some status value before changing setup (such as tranmitted power of green laser)
• Revise setup after a new lens arrives
• Align the setup and check mode-matching
• Measure status value again and confirm it improves
• (write programming code of making alignment control automatically)
14218   Thu Sep 27 14:02:55 2018 yukiConfigurationASCPZT driver board verification

[ Yuki, Gautam ]

I fixed the input terminal that had been off, and made sure PZT driver board performs as we expect.

At first I ran a simulation of the PZT driver circuit using LTspice (Attached #1 and #2). It shows that when the bias is 30V the driver performs well only with high input volatage (bigger than 3V). Then I measured the performance as following way:

1. Applied +-15V to the board with an expansion card and 31.8V to the high voltage port which is the maximum voltage of PS280 DC power supplier C10013.
2. Terminated input and connectd input bias to GND, then set offset to -10.4V. This value is refered as elog:40m/8832.
3. Injected DC signal into input port using a function generator.
4. Measured voltage at the OUT port and MON port.

The result of this is attached #3 and #4. It is consistent with simulated one. All ports performed well.

• V(M1_PIT_OUT) = -4.86 *Vin +49.3 [V]
• V(M1_YAW_OUT) = -4.86 *Vin +49.2 [V]
• V(M2_PIT_OUT) = -4.85 *Vin +49.4 [V]
• V(M2_YAW_OUT) = -4.86 *Vin +49.1 [V]
• V(M1_PIT_MON) = -0.333 *Vin +3.40 [V]
• V(M1_YAW_MON) = -0.333 *Vin +3.40 [V]
• V(M2_PIT_MON) = -0.333 *Vin +3.40 [V]
• V(M2_YAW_MON) = -0.333 *Vin +3.40 [V]

The high voltage points (100V DC) remain to be tested.

Attachment 1: PZTdriverSimulationDiagram.pdf
Attachment 2: PZTdriverSimulationResult.pdf
Attachment 3: PZTdriverPerformanceCheck_ResultOUT.pdf
Attachment 4: PZTdriverPerformanceCheck_ResultMON.pdf
Attachment 5: PZTdriver.asc
Version 4
SHEET 1 2120 2120
WIRE 1408 656 1408 624
WIRE 1552 656 1552 624
WIRE 1712 656 1712 624
WIRE 1872 656 1872 624
WIRE 2016 656 2016 624
WIRE 1408 768 1408 736
WIRE 1552 768 1552 736
WIRE 1712 768 1712 736

... 193 more lines ...
14219   Sun Sep 30 20:14:51 2018 yukiConfigurationASCQPD calibration

[ Yuki, Gautam, Steve ]

Results:
I calibrated a QPD (D1600079, V1009) and made sure it performes well. The calibration constants are as follows:

X-Axis: 584 mV/mm
Y-Axis: 588 mV/mm

Details:
The calibration of QPD is needed to calibrate steeing PZT mirrors. It was measured by moving QPD on a translation stage. The QPD was connected to its amplifier (D1700110-v1) and +-18V was supplied from DC power supplier. The amplifier has three output ports; Pitch, Yaw, and Sum. I did the calibration as follows:

• Center beam spot on QPD using steering mirror, which was confirmed by monitored Pitch and Yaw signals that were around zero.
• Kept Y-axis micrometer fixed, moved X-axis micrometer and measured the outputs.
• Repeated the procedure for the Y-axis.

The results are attached. The main signal was fitted with error function and I drawed a slope at zero crossing point, which is calibration factor. I determined the linear range of the QPD to be when the output was in range -50V to 50V, then corresponding displacement range is about 0.2 mm width. Using this result, the PZT mirrors will be calibrated in linear range of the QPD tomorrow.

• Some X-Y coupling existed. When one axis micrometer was moved, a little signal of the other direction was also generated.
• As Gautam proposed in the previous study, there is some hysteresis. That process would bring some errors to this result.
• A scale of micrometer is expressed in INCH!
• The micrometer I used was made to have 1/2 inch range, but it didn't work well and the range of X-axis was much narrower.

Reference:
previous experiment by Gautam for X-arm: elog:40m/8873, elog:40m/8884

Attachment 1: QPDcalibrationXaxis.pdf
Attachment 2: QPDcalibrationYaxis.pdf
14221   Mon Oct 1 13:33:55 2018 yukiConfigurationASCQPD calibration
 Quote: I assume this QPD set is a D1600079/D1600273 combo. How much was the SUM output during the measurement? Also how much were the beam radii of this beam (from the error func fittings)? Then the calibration [V/m] is going to be the linear/inv-linear function of the incident power and the beam radus. You mean the linear range is +/-50mV (for a given beam), I guess.
• The SUM output was from -174 to -127 mV.
• The beam radii calculated from the error func fittings was 0.47 mm.
• Total optical path length measured by a ruler= 36 cm.
• Beam power measured at QPD was 2.96 mW. (There are some loss mechanism in the setup.)

Then the calibration factor of the QPD is

X axis: 584 * (POWER / 2.96mW) * (0.472mm /  RADIUS) [mV/mm]
Y axis: 588 * (POWER / 2.96mW) * (0.472mm /  RADIUS) [mV/mm].

Attachment 1: Pic_QPDcalibration.jpg
14224   Tue Oct 2 18:50:53 2018 yukiConfigurationASCPZT mirror calibration

[ Yuki, Gautam ]

I calibrated PZT mirrors. The ROUGH result was attached. (Note that some errors and trivial couplings coming from inclination of QPD were not considered here. This should be revised and posted again.)

The PZT mirrors I calibrated were:

• A 2-inch CVI mirror (45 degree, HR and AR for 532nm)
• A 1-inch Laseroptik mirror (45 degree, HR and AR for 532nm)

I did the calibration as follows:

• +-15V was supplied to PZT driver circuit, +100V to PZT driver bias, and +-18V to QPD amplifier.
• Optical path length was set to be same as that when I calibrated QPD, which is 36cm.
• The full range of CVI mirror is 3.5mrad according to its datasheet and linear range of QPD is 0.2mm, so I set the distance between PZT mirrors and QPD to be about 6cm. (I realized it was wrong. When mirror tilts 1 deg, the angle of beam changes 2 deg. So the distance should be the half.)
• After applying 0V to PZT driver input (at that time 50V was applied to PZT mirror), then centered beam spot on QPD using steering mirror, which was confirmed by monitored Pitch and Yaw signals of QPD that were around zero.
• In order to avoid hysteresis effect, I stared with an input signal of -10V. I then increased the input voltage in steps of 1V through the full range from -10V to +10V DC. The other input was kept 0V.
• Both the X and Y coordinates were noted in the plot in order to investigate pitch-yaw coupling.

The calibration factor was

• I made sure that PZT mirrors move linearly in full input range (+-10V).
• PZT CH1 input: Yaw, CH2: Pitch, CH3: +100V bias
• The calibration factor of PZT mirrors [mrad/V] are not consistent with previous calibration (elog:40m/8967). I will check it again.
• I measured the beam power in order to calibrate QPD responce with a powermeter, but it didn't have high precision. So I used SUM output of QPD to the calibration.
• Full range of PZT mirrors looks 2 times smaller.

Reference:
Previous calibration of the same mirrors, elog:40/8967

Attachment 1: PZTM1calibrationCH2.pdf
Attachment 2: PZTM1calibrationCH1.pdf
Attachment 3: PZTM2calibrationCH2.pdf
Attachment 4: PZTM2calibrationCH1.pdf
14226   Wed Oct 3 14:24:40 2018 yukiConfigurationASCY end table upgrade plan

Interim Procedure Report:

Purpose

The current setup of AUX Y-arm Green locking has to be improved because:

• current efficiency of mode matching is about 50%
• current setup doesn't separate the degrees of freedom of TEM01 with PZT mirrors (the difference of gouy phase between PZT mirrors should be around 90 deg)
• we want to remotely control PZT mirrors for alignment

What to do

• Design the new setup and order optices needed (finished!)
- As the new setup I designed, adding a new lens and slightly changing the position of optics are only needed. The new lens was arrived here.
• Check electronics (PZT, PZT driver, high voltage, cable, anti-imaging board) (finished!)

- All electronics were made sure performing well.
- The left thing to do is making a cable. (Today's tasks)
• Calibrate PZT mirror [mrad/V] (finished!)

- The result was posted here --> elog:40m/14224.
• Measure the status value of the current setup (power of transmitted light ...etc) (Tomorrow, --> finished!)
• Install them in the Y-end table and align the beam (Will start from Tomorrow) (The setup has a probrem I found on 10/04)
• Measure the status value of the new setup
- I want to finish above during my stay.
• Prepare the code of making alignment automaticaly
14227   Wed Oct 3 18:15:34 2018 yukiConfigurationASCAI board improvement

[ Yuki, Gautam ]

I improved Anti-Imaging board (D000186-Rev.D), which will be put between DAC port and PZT driver board.

It had notches at f = 16.6 kHz and 32.7 kHz, you can see them in the plot attached. So I replaced some resistors as follows:

• R6 and R7 replaced with 511 ohm (1206 thin film resistor)
• R8 replaced with 255 ohm (1206 thin film resistor)
• R14 and R15 replaced with 549 ohm (1206 thin film resistor)
• R16 replaced with 274 ohm (1206 thin film resistor)

Then the notch moved to 65.9 kHz (> sampling frequency of DAC = 64 kHz, good!).
(The plot enlarged around the notch frequency and the plot of all channels will be posted later.)

All electronics and optics seem to be ready.

Reference, elog:40m/8857
Diagram, D000186-D.pdf

Attachment 1: TF_AIboard.pdf
14228   Thu Oct 4 00:44:50 2018 yukiConfigurationASCAI board improvement

[ Yuki, Gautam ]

I made a cable which connects DAC port (40 pins) and AI board (25 pins). I will check if it works.

Tomorrow I will change setup for improvement of AUX Y-end green locking. Any optics for IR will not be moved in my design, so this work doesn't affect Y-arm locking with main beam.
While doing this work, I will do:

• check if the cable works
• make another cable which connects AI board (10 pins) and PZT driver (10 pins).
• check if eurocate in Y-rack (IY4?) applies +/-5V, +/-15V and +/-24V. It will be done using an expansion card.
• improve alignment servo for X-end.
• setup alignment servo for Y-end.