40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
 40m Log, Page 329 of 335 Not logged in
ID Date Author Type Category Subject
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.
14230   Thu Oct 4 22:15:30 2018 yukiConfigurationASCY-end table upgrade

Before changing setup at Y-end table, I measured the status value of the former setup as follows. These values will be compared to those of upgraded setup.

• beam power going into doubling crystal (red12): 20.9 mW with filter, 1064nm
• beam power going out from doubling crystal (red12): 26.7 mW with filter, 532nm
• beam power going into faraday isolator (green5): 0.58 mW without filter, 532nm
• beam power going out from faraday isolator (green5): 0.54 mW without filter, 532nm
• beam power going to ETMY: 0.37 mW without filter, 532nm
• beam power of transmitted green light of Y-arm, which was measured by C1:ALS-TRY_OUT: 0.5 (see attachment #1)

(These numbers are shown in the attachment #2.)

The setup I designed is here. It can bring 100% mode-matching and good separation of degrees of TEM01, however I found a probrem. The picture of setup is attached #3. You can see the reflection angle at Y7 and Y8 is not appropriate. I will consider the schematic again.

Attachment 1: AUXYGreenLock20180921.jpg
Attachment 2: Pic_FormerSetup.jpeg
Attachment 3: Pic_CurrentSetup1004.jpg
14232   Fri Oct 5 17:32:38 2018 yukiConfigurationASCY-end table upgrade

I measured it with the wrong setting of a powermeter. The correct ones are here:

• beam power going into doubling crystal (red12): 240 mW, 1064nm
• beam power transmitted dichroic mirror (Y5): 0.70 mW, 532nm
• beam power going into faraday isolator (green5): 0.58 mW, 532nm
• beam power going out from faraday isolator (green5): 0.54 mW, 532nm
• beam power going to ETMY: 0.37 mW, 532nm
• beam power of transmitted green light of Y-arm, which was measured by C1:ALS-TRY_OUT: 0.5 (see attachment #1)

The calculated conversion efficiency of SHG crystal is 1.2%W.

14234   Fri Oct 5 22:49:22 2018 yukiConfigurationASCY-end table upgrade

I designed a new layout. It has good mode-matching efficiency, reasonable sensitivity to component positions, good Gouy phase separation. I'm setting optics in the Y-end table. The layout will be optimized again after finishing (rough) installation.  (The picture will be posted later)

14236   Sun Oct 7 22:30:42 2018 yukiConfigurationLSCYarm Green locking was recovered

I finished installation of optics in the Y-end and recovered green locking. Current ALS-TRY_OUTPUT is about 0.25, which is lower than before. So I still continue the alignment of the beam. The simulation code was attached. (Sorry. The optic shown as QWP2 is NOT QWP. It's HWP.)

Attachment 1: Pic_NewLayout1007.jpg
Attachment 2: YendGreenModeMatching.zip
14237   Mon Oct 8 00:46:35 2018 yukiConfigurationASCY-end table upgrade
 Quote: I measured it with the wrong setting of a powermeter. The correct ones are here: beam power going into doubling crystal (red12): 240 mW, 1064nm beam power transmitted dichroic mirror (Y5): 0.70 mW, 532nm beam power going into faraday isolator (green5): 0.58 mW, 532nm beam power going out from faraday isolator (green5): 0.54 mW, 532nm beam power going to ETMY: 0.37 mW, 532nm beam power of transmitted green light of Y-arm, which was measured by C1:ALS-TRY_OUT: 0.5 (see attachment #1)

After installation I measured these power again.

• beam power going into doubling crystal: 241 mW, 1064nm
• beam power transmitted dichroic mirror: 0.70 mW, 532nm
• beam power going into faraday isolator: 0.56 mW, 532nm
• beam power going out from faraday isolator: 0.53 mW, 532nm
• beam power going to ETMY: 0.36 mW, 532nm

There is a little power loss. That may be because of adding one lens in the beam path. I think it is allowable margin.

14240   Tue Oct 9 23:03:43 2018 yukiConfigurationLSCYarm Green locking was recovered

[ Yuki, Gautam, Steve ]

To align the green beam in Y-end these hardware were installed:

• PZT mirrors in Y-end table
• PZT driver in 1Y4 rack
• Anti-Imaging board in 1Y4 rack
• cables (DAC - AIboard - PZTdriver - PZT)
• high voltage supplier

I made sure that DAC CH9~16 and cable to AI-board worked correctly.

When we applied +100V to PZT driver and connected DAC, AI-board and PZT drive, the output voltage of the driver was not correct. I'll check it tomorrow.

Attachment 1: Pic_1Y4.jpg
Attachment 2: Pic_PZTcable.jpg
14241   Wed Oct 10 12:38:27 2018 yukiConfigurationLSCAll hardware was installed

I connected DAC - AIboard - PZTdriver - PZT mirrors and made sure the PZT mirrors were moving when changing the signal from DAC. Tomorrow I will prepare alignment servo with green beam for Y-arm.

14243   Thu Oct 11 13:40:51 2018 yukiUpdateComputer Scripts / Programsloss measurements
 Quote: This is the procedure I follow when I take these measurements for the XARM (symmetric under XARM <-> YARM): Dither-align the interferometer with both arms locked. Freeze outputs when done. Misalign ETMY + ITMY. ITMY needs to be misaligned further. Moving the slider by at least +0.2 is plentiful to not have the other beam interfere with the measurement. Start the script, which does the following: Resume dithering of the XARM Check XARM dither error signal rms with CDS. If they're calm enough, proceed. Freeze dithering Start a new set of averages on the scope, wait T_WAIT (5 seconds) Read data (= ASDC power and MC2 trans) from scope and save Misalign ETMX and wait 5s Read data from scope and save Repeat desired amount of times Close the PSL shutter and measure the PD dark levels

Information for the armloss measurement:

• Script which gets the data:  /users/johannes/40m/armloss/scripts/armloss_scope/armloss_dcrefl_asdcpd_scope.py
• Script which calculates the loss: /users/johannes/40m/armloss/scripts/misc/armloss_AS_calc.py
• Before doing the procedure Johannes wrote you have to prepare as follows:
• put a PD in anti-symmetric beam path to get ASDC signal.
• put a PD in MC2 box to get tranmitted light of IMC. It is used to normalize the beam power.
• connect those 2 PDs to oscilloscope and insert an internet cable to it.
• Usage: python2 armloss_dcrefl_asdcpd_scope.py [IP address of Scope] [ScopeCH for AS] [ScopeCH for MC] [Num of iteration] [ArmMode]

Note: The scripts uses httplib2 module. You have to install it if you don't have.

The locked arms are needed to calculate armloss but the alignment of PMC is deadly bad now. So at first I will make it aligned. (Gautam aligned it and PMC is locked now.)

gautam: The PMC alignment was fine, the problem was that the c1psl slow machine had become unresponsive, which prevented the PMC length servo from functioning correctly. I rebooted the machine and undid the alignment changes Yuki had made on the PSL table.

14245   Fri Oct 12 12:29:34 2018 yukiUpdateComputer Scripts / Programsloss measurements

With Gautam's help, Y-arm was locked. Then I ran the script "armloss_dcrefl_asdcpd_scope.py" which gets the signals from oscilloscope. It ran and got data, but I found some problems.

1. It seemed that a process which makes arm cavity mislaigned in the script didn't work.
2. The script "armloss_dcrefl_asdcpd_scope.py" gets the signal and the another script "armloss_AS_calc.py" calculates the arm loss. But output file the former makes doesn't match with the type the latter requires. A script converts format is needed.

Anyway, I got the data needed so I will calculate the loss after converting the format.

14248   Fri Oct 12 20:20:29 2018 yukiUpdateComputer Scripts / Programsloss measurements

I ran the script for measuring arm-loss and calculated rough Y-arm round trip loss temporally. The result was 89.6ppm. (The error should be considered later.)

The measurement was done as follows:

1. install hardware
1. Put a PD (PDA520) in anti-symmetric beam path to get ASDC signal.
2. Use a PD (PDA255) in MC2 box to get tranmitted light of IMC. It is used to normalize the beam power.
3. Connect those 2 PDs to oscilloscope (IP: 192.168.113.25) and insert an internet cable to it.
2. measure DARK noise
1. Block beam going into PDs with dampers and turn off the room light.
2. Run the script "armloss_dcrefl_acdcpd_scope.py" using "DARK" mode.
3. measure the ASDC power when Y-arm locked and misaligned
1. Remove dampers and turn off the room light.
2. Dither-align the interferometer with both arms locked. Freeze outputs when done. (Click C1ASS.adl>!MoreScripts>ON and click C1ASS.adl>!MoreScripts>FreezeOutputs.)
3. Misalign ETMX + ITMX. (Just click "Misalign" button.)
4. Further misalign ITMX with the slider. (see previous study: ITMX needs to be misaligned further. Moving the slider by at least +0.2 is plentiful to not have the other beam interfere with the measurement.)
5. Start the script "armloss_dcrefl_acdcpd_scope.py" using "ETMY" mode, which does the following:
1. Resume dithering of the YARM.
2. Check YARM dither error signal rms with CDS. If they're calm enough, proceed. (In the previous study the rms threshold was 0.7. Now "ETM_YAW_L_DEMOD_I" signal was 15 (noisy), then the threshold was set 17.)
3. Freeze dithering.
4. Start a new set of averages on the scope, wait T_WAIT (5 seconds).
5. Read data (= ASDC power and MC2 trans) from scope and save.
6. Misalign ETMY and wait 5s. (I added a code which switchs LSC mode ON and OFF.)
7. Read data from scope and save.
8. Repeat desired amount of times.
4. calculate the arm loss
1. Start the script "armloss_AS_calc.py", whose content is follows:
• requires given parameters: Mode-Matching effeciency, modulation depth, transmissivity. I used the same value as Johannes did last year, which are (huga)
• reads datafile of beam power at ASDC and MC2 trans, which file is created by "armloss_dcrefl_acdcpd_scope.py".
• calculates arm loss from the equation (see 12528 and 12854).

Result:

YARM
('AS_DARK =', '0.0019517200000000003') #dark noise at ASDC
('MC_DARK =', '0.02792') #dark noise at MC2 trans
('AS_LOCKED =', '2.04293') #beam power at ASDC when the cavity was locked
('MC_LOCKED =', '2.6951620000000003')
('AS_MISALIGNED =', '2.0445439999999997') #beam power at ASDC when the cavity was misaligned
('MC_MISALIGNED =', '2.665312')

$\hat{P} = \frac{P_{AS}-P_{AS}^{DARK}}{P_{MC}-P_{MC}^{DARK}}$ #normalized beam power

$\hat{P}^{LOCKED}=0.765,\ \hat{P}^{MISALIGNED}=0.775,\ \mathcal{L}=89.6\ \mathrm{ppm}$

• "ETM_YAW_L_DEMOD_I_OUTPUT" was little noisy even when the arm was locked.
• The reflected beam power when locked was higher than when misaligned. It seemed strange for me at first. Johannes suggested that it was caused by over-coupling cavity. It is possible when r_{ETMY}>>r1_{ITMY}.
• My first (wrong) measurement said the arm loss was negative(!). That was caused by lack of enough misalignment of another arm mirrors. If you don't misalign ITMX enough then the beam or scattered light from X-arm would bring bad. The calculated negative loss would be appeared only when $\frac{\hat{P}^{LOCKED}}{\hat{P}^{MISALIGNED}} > 1 + T_{ITM}$
• Error should be considered.
• Parameters given this time should be measured again.
14251   Sat Oct 13 20:11:10 2018 yukiUpdateComputer Scripts / Programsloss measurements
 Quote: the script "armloss_AS_calc.py", "ETM_YAW_L_DEMOD_I_OUTPUT" was little noisy even when the arm was locked. The reflected beam power when locked was higher than when misaligned. It seemed strange for me at first. Johannes suggested that it was caused by over-coupling cavity. It is possible when r_{ETMY}>>r1_{ITMY}.

Some changes were made in the script for getting the signals of beam power:

• The script sees "C1:ASS-X(Y)ARM_ETM_PIT/YAW_L_DEMOD_I_OUTPUT" and stops running until the signals become small, however some offset could be on the signal. So I changed it into waiting until (DEMOD - OFFSET) becomes small. (Yesterday I wrote ETM_YAW_L_DEMOD_I_OUTPUT was about 15 and was little noisy. I was wrong. That was just a offset value.)
• I added a code which stops running the script when the power of transmitted IR beam is low. You can set this threshold. The nominal value of "C1:LSC-TRX(Y)_OUT16" is 1.2 (1.0), so the threshold is set 0.8 now.

In the yesterday measurement the beam power of ASDC is higher when locked than when misaligned and I wrote it maybe caused by over-coupled cavity. Then I did a calculation as following to explain this:

• assume power transmissivity of ITM and ETM are 1.4e-2 and 1.4e-5.
• assume loss-less mirror, you can calculate amplitude reflectivity of ITM and ETM.
• consider a cavity which consists two mirrors and is loss-less, then $\frac{E_{r}}{E_{in}} = \frac{-r_1+r_2e^{i\phi}}{1-r_1r_2e^{i\phi}}$ holds. r1 and r2 are amplitude reflectivity of ITM and ETM, and E is electric filed.
• Then you can calculate the power of reflected beam when resonated and when anti-resonated. The fraction of these value is $\frac{P_{RESONANT}}{P_{ANTI-RESO}} = 0.996$, which is smaller than 1.
• I found this calculation was wrong! Above calculatation only holds when cavity is aligned, not when misaligned. 99.04% of incident beam power reflects when locked, and (100-1.4)% reflects when misaligned. The proportion is P(locked)/P(misaligned)=1.004, higher than 1.

14254   Mon Oct 15 10:32:13 2018 yukiUpdateComputer Scripts / Programsloss measurements

I used these values for measuring armloss:

• Transmissivitity of ITM = 1.384e-2 * (1 +/- 1e-2)
• Transmissivitity of ETM = 13.7e-6 * (1 +/- 5e-2)
• Mode-Matching efficiency of XARM = 0.912 * (1 +/- 2e-2)
• Mode-Matching efficiency of YARM = 0.867 * (1 +/- 2e-2)
• modulation depth m1 (11MHz) = 0.179 * (1 +/- 2e-2)
• modulation depth m2 = 0.226 * (1 +/- 2e-2),

then the uncertainties reported by the individual measurements are on the order of 6 ppm (~6.2 for the XARM, ~6.3 for the YARM). This accounts for fluctuations of the data read from the scope and uncertainties in mode-matching and modulation depths in the EOM. I made histograms for the 20 datapoints taken for each arm: the standard deviation of the spread is over 6ppm. We end up with something like:

XARM: 123 +/- 50 ppm
YARM: 152+/- 50 ppm

This result has about 40% of uncertaintities in XARM and 33% in YARM (so big... ).

In the previous measurement, the fluctuation of each power was 0.1% and the fluctuation of P(Locked)/P(misaligned) was also 0.1%. Then the uncertainty was small. On the other hand in my measurement, the fluctuation of power is about 2% and the fluctuation of P(Locked)/P(misaligned) is 2%. That's why the uncertainty became big.

We want to measure tiny value of loss (~100ppm). So the fluctuation of P(Locked)/P(misaligned) must be smaller than 1.6%.

(Edit on 10/23)
I think the error is dominated by systematic error in scope. The data of beam power had only 3 degits. If P(Locked) and P(misaligned) have 2% error, then
$\frac{P_L}{P_M}\frac{1}{1+T_{\mathrm{ITM}}} = 0.99(3)$.
You have to check the configuration of scope.

Attachment 1: XARM_20181015_1500.pdf
Attachment 2: YARM_20181015_1500.pdf
 Quote: but there's one weirdness: It get's the channel offset wrong. However this doesn't matter in our measurement because we're subtracting the dark level, which sees the same (wrong) offset.

When you do this measurement with oscilloscope, take care two things:

1. set y-range of scope as to every signal fits in display: otherwise the data sent from scope would be saturated.
2. set y-position of scope to the center and don't change it; otherwise some offset would be on the data.
14257   Mon Oct 15 20:11:56 2018 yukiConfigurationASCY end table upgrade plan

Final Procedure Report for Green Locking in YARM:

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) (finished!)
• Install them in the Y-end table and align the beam (Almost finished!) (GTRY signal is 0.3 which means Mode-Matching efficiency is about 30%. It should be improved.)
• Measure the status value of the new setup (finished!)
• Prepare the code of making alignment automaticaly
• see sitemap.adl>ASC>c1asy. I prepared medm. If you move PZT SLIDERS then you can see the green beam also moves.
• Preparing filters is needed. You can copy them from C1ASX.
• Note that now you cannot use C1ASX servo because filters are not applied.
14258   Tue Oct 16 00:44:29 2018 yukiUpdateComputer Scripts / Programsloss measurements

The scripts for measuring armloss are in the directory "/opt/rtcds/caltech/c1/scripts/lossmap_scripts/armloss_scope".

• armloss_derefl_asdcpd_scope.py: gets data and makes ascii file.
• armloss_AS_calc.py: calculates armloss from selected a set of files.
• armloss_calc_histogram.py: calculates armloss from selected files and makes histogram.
14260   Wed Oct 17 20:46:24 2018 yukiConfigurationASCY end table upgrade plan

To do for Green Locking in YARM:

The auto-alignment servo should be completed. This servo requires many parameters to be optimized: demodulation frequency, demodulation phase, servo gain (for each M1/2 PIT/YAW), and matrix elements which can remove PIT-YAW coupling.

14280   Wed Nov 7 05:16:16 2018 yukiUpdateComputer Scripts / Programsarm loss measuremenents

Please check your data file and compare with those Johannes made last year. I think the power in your data file may have only three-disits and flactuate about 2%, which brings huge error. (see elog: 40m/14254)

 Quote: On running the script again, I'm getting negative values for the loss.
3622   Wed Sep 29 16:56:36 2010 yutaUpdateVAC2 doors opened

(Steve, Koji, Joe, Kiwamu, Yuta)

Background:
The vent was started on Monday, and finished on Tuesday.
We were to open the doors on Tuesday, but we couldn't because the vertex crane got out of order.
Now the crane was fixed, and so we opened the doors today.

What we did:

We opened the north side of the BS chamber and the west side of the ITMX chamber.
Now, the light doors are put instead.

3623   Wed Sep 29 18:28:32 2010 yutaUpdateComputersaldabella connects to the wireless network

Background:
We need laptops that connect to the wireless network to use them in the lab.

aldabella:
Dell Inspiron E1505 laptop
Broadcom Corporation BCM4311 802.11b/g WLAN (rev 01) (PCIID: 14e4:4311 (rev 01))

What I did:
1. I followed this method(Japanese!): http://www.linuxmania.jp/wireless_lan.html
Except I installed ndiswrapper-1.56 and cabextracted sp32156.exe.
Also, I didn't run
# ndiswrapper -m

2. Then I did step #6 in here: http://nodus.ligo.caltech.edu:8080/40m/1275
Note that the hardware is eth1 instead of wlan0.

3. Added the following line to /etc/rc.d/rc.local to make ndiswrapper load on every boot:
 /sbin/modprobe ndiswrapper

Result:
aldabella now connects to the wireless martian network on every boot!!

Note:
Somehow, the method that uses Broadcom official driver doesn't work.
It returns the following error when activating eth1:   Error for wireless request "Set Encode" (8B2A) :     SET failed on device eth1 ; Invalid argument.   Error for wireless request "Set Encode" (8B2A) :     SET failed on device eth1; Invalid argument.

3627   Thu Sep 30 14:09:33 2010 yutaUpdateComputersmariabella connects to the wireless network

Background:
We need laptops that connect to the wireless network to use them in the lab.

mariabella:
Dell Inspiron 1210 laptop
Broadcom Corporation BCM4312 802.11b/g (rev 01) (PCIID: 14e4:4315 (rev 01))

What I did:
1. I followed the same steps I did for aldabella: http://nodus.ligo.caltech.edu:8080/40m/3623
Except I unzipped R151517-pruned.zip.

2. Note that the PCIID is important for driver selection. Not the model No.
To check whether your driver selection is correct, run:
# ndiswrapper -l
after installing the driver.
If the driver selection is wrong, it will return only:
bcmwl5 : driver installed
If correct, it will return:
bcmwl5 : driver installed          device (14E4:4315) present (alternate driver: hoge)

Result:
aldabella now connects to the wireless martian network.

Note:

Broadcom official driver didn't work for mariabella, too.

3630   Thu Sep 30 18:51:50 2010 yutaUpdateComputerssetting up aldabella and mariabella

(Kiwamu, Yuta)

Background:
We wanted to make aldabella and mariabella know how to work.

What we did:

1. Added 2 lines to /etc/rc.local
 /sbin/modprobe ndiswrapper  sleep 10  mount linux1:/home/cds/ /cvs/cds

2. Edited ~/.cshrc
 source /cvs/cds/caltech/cshrc.40m

Result:
Working environment is set to aldabella and mariabella. They have their access to the main system, linux1, now.

Note:
fstab doesn't work for aldabella and mariabella because the mount should be done after ndiswrapper loads.

3645   Mon Oct 4 19:48:00 2010 yutaUpdateVACseveral mirrors installed to ITMX/BS chamber

(Koji, Kiwamu, Yuta)

Lots of progress for the optics placement in the vacuum chamber.
We are ready to go to the next step: open the access connector between IMC and OMC.

### Background:

The actual work in the vacuum chamber started.
The first goal of the vent is to get the green beam coming out from the chambers to the PSL table.

### What we did:

1. Inspection of the tip-tilt suspension

The alignments of the TTs were inspected. We had five TTs having been sitting on the table in Bob's clean room.
Prior to their installation we checked the alignments of those because they sometimes showed large hysteresis mainly in the pitch directions.

If a TT has the hysteresis, the pitch position doesn't come back to the previous position. This may cause an issue of the interferometer operation.

- SN001, SN003, SN005 looked well aligned and show no hysteresis.

- The alignment of SN002 was not so good (theta ~ 0.004 rad ) compared to those three, but no hysteresis, we think this guy is still acceptable for the installation.

- SN004 had an apparent hysteresis. This guy doesn't come back to the previous place, being applied a touch. We have to fix this at some point.

2. Work in the ITMX chamber

Now all of the optic in this chamber was installed in the approximate place.

- Installed POX/POP steering mirrors.

- TT(SN003) was placed.

- The two steering optics for ITMX OPLEV were placed at the designed positions.

3. Work in the BS chamber

Installed 2 TTs to the BS chamber.
- SR3: TT(SN001)
- PR3: TT(SN005)

After the alignment of the green steering mirrors, we confirmed
the green beam is successfully hitting the west wall of the OMC chamber.

Those TTs are approximately aligned using the weakly reflected green beams.

### Next work:

- Open the access connector

- Place another periscope and two steering mirrors for green

- Damping of the suspended optics

- Resurrect MC and its stable lock

- Remove MCT pickoff path

- Align optics in the main path

- Recycled Michelson lock

Attachment 1: P1060901.JPG
Attachment 2: P1060904.JPG
3656   Tue Oct 5 21:22:46 2010 yutaUpdateVACgreen beam reached PSL table

YES ! We got the green light coming out from the OMC chamber to the PSL table !

(Koji, Kiwamu, Yuta)

Background

As a result of the work in the chambers, the green beam reached the OMC chamber yesterday.
Today's mission was to let the green beam coming out from the chambers to the PSL table.

What we did:
1. Installed the last three steering mirrors.
The mirrors were 532 HR mirror with AR and 1deg wedge (CVI Y2-LW-1-2050-UV-45-P/AR).
Two of them are placed to the MC chamber. Another one was to the OMC chamber

During putting the mirrors to the MC chamber, we found that a cable tower was sitting on a position exactly where we wanted to put one of the mirrors.

So we moved the tower to the very south west corner.

2. Installed a periscope to the MC chamber

The function of this periscope is to lower the beam height of the green light which is risen up by another periscope in the BS chamber.

We aligned it to the green beam, so that the beam hits the center of the mirrors on the periscope.

3. Aligned the optics

We aligned the green mirrors so that we can let the green beam go out from the chamber.

Actually the inside of the OMC chamber didn't look like the same as that of our optical layout.

For example there is unknown base plate, which apparently disturbs the location of our last steering mirror.

Therefore we had to change the designed position of the steering mirror.

Now the mirror is sitting near the designed position (~ 1/2 inch off), but it's fine because it doesn't clip any 1064 beam.

Result:

The green beam is now hitting the north wall of the PSL table.

Notes:

The green beam looks having some fringes, it may be caused by a multiple reflection from a TT when the green beam goes through it. We are going to check it.

Next work:

- Damping of the suspended optics

- Resurrect MC and its stable lock

- Remove MCT pickoff path

- Align optics in the main path

- Recycled Michelson lock

3667   Thu Oct 7 14:39:50 2010 yutaUpdatePSLmeasured PMC's laser power-output relation

(Rana, Yuta)

Motivation:

We wanted to see thermal effects on the PMC.

What I did yesterday:
Changed the current of the NPRO from 2A to 0.8A and measured the power of the reflected/transmitted light from the PMC when locked.
I also measured the power of the reflected light when PMC is not locked (It supposed to be proportional to the output power of the laser).

Result:
Attached. Hmmmm......
At several points of the laser current, I could'nt lock the PMC very well. The power of the reflected/transmitted light depend on the offset voltage of the PZT.
When the laser power was weak(~<0.9A), the power of reflected/transmitted light changed periodically(~ several minutes).

Attachment 1: PMCreflect.png
3672   Thu Oct 7 16:34:06 2010 yutaUpdatePSLmeasured PMC's laser power-output relation

Result2:
Attached is the visibility vs incident power(assuming output of the PD is proportional to the input laser power).
Ideally, the graph should be flat. (In another words, attached graph in the elog #3667 shoud be linear.)
But the visibility reduces with higher laser power in this graph. This is maybe because of the thermal effect. I'm thinking about how to confirm this.

Quote:

It was a bit difficult to comprehend the result.
Is it good? or bad? Have you seen the thermal effect? or not?

- Put linear lines to show the visibility of the cavity.

- Calibrate the incident power and make another plot to show the visibility (%) vs the incident power (W).

 Quote: (Rana, Yuta) Motivation:  We wanted to see thermal effects on the PMC. What I did yesterday:  Changed the current of the NPRO from 2A to 0.8A and measured the power of the reflected/transmitted light from the PMC when locked.  I also measured the power of the reflected light when PMC is not locked (It supposed to be proportional to the output power of the laser). Result:  Attached. Hmmmm......  At several points of the laser current, I could'nt lock the PMC very well. The power of the reflected/transmitted light depend on the offset voltage of the PZT.  When the laser power was weak(~<0.9A), the power of reflected/transmitted light changed periodically(~ several minutes).

Attachment 1: PMCvis.png
3674   Thu Oct 7 17:53:07 2010 yutaUpdateComputersFarfalla with Firefox, fixed

(Kiwamu, Yuta)

Symptom:
Farfalla(Acer Aspire one KAV60 netbook) couldn't run Firefox and returned the following error:
Error: platform version '1.9.2.8' is not compatible with
minVersion >= 1.9.2.9
maxVersion <= 1.9.2.9

What we did:
1. Added the following line to ~/.cshrc.
alias firefox "/usr/lib/firefox-3.6/firefox"
2. Made a cool launcher for firefox.

Result:
Farfalla can fly into the web with Firefox now.

Notes:

Even if it was then before, bash could run firefox. tsch couldn't.
The command firefox was /cvs/cds/caltech/apps/linux/bin/firefox for tsch, because of the source /cvs/cds/caltech/cshrc.40m.
I did this to zita which had the same symptom, too.

Next work:

Farfalla wakes up on the wrong side of the bed. This has to be fixed.

3675   Thu Oct 7 23:24:44 2010 yutaUpdateCDSchecking MC1 suspension damping

Background:
The new CDS is currently being set up.
We want to see if the damping servo of the suspensions are working correctly.
But before that, we have to see if the sensors and the coils are working correctly.
Among the 8 optics, MCs take top priority because of the green beam. for the alignment of the in-vac optics.

What I did:
By seeing the 5 sensor outputs (C1:SUS-MC1_XXSEN_IN1, XX=UL,UR,LR,LL,SD) with the Data Viewer, I checked if all the coils are kicking in the supposed direction and all the sensors are sensing that kick correctly.

All the matrices elements were set to the ideal values(-1 or 0 or 1) this time.

Result:
They were perfect.
1. POSITION seemed to be POSITION
When the offset(C1:SUS-MC1_SUSPOS_OFFSET) was added, all the sensor output moved to the same direction.
2. PITCH seemed to be PITCH
When the offset(C1:SUS-MC1_PIT_COMM) was changed, UL&UR and LL&LR went to the different direction.
3. YAW seemed to be YAW
When the offset(C1:SUS-MC1_YAW_COMM) was changed, UL&LL and UR&LR went to the different direction.
4. SIDE seemed to be SIDE
When the offset(C1:SUS-MC1_SDSEN_OFFSET) was added, DC level of the SD sensor output changed.

Notes:

c1mcs crashed many times during the investigation, and I had to kill and restart it again and again.
It seemed to be easily crashed when filters are on, and so I couldn't check whether the damping servo is working correctly or not today.

Next work:

- fix c1mcs (and maybe others)
- check the damping servo by comparing the displacements of each 4 degrees of freedom when servo in off and on.

3689   Mon Oct 11 16:09:10 2010 yutaSummarySUScurrent OSEM outputs

Background:
The output range of the OSEM is 0-2V.
So, the OSEM output should fluctuate around 1V.
If not, we have to modify the position of it.

What I did:
Measured current outputs of the 5 OSEMs for each 8 suspensions by reading sensor outputs(C1:SUS-XXX_YYPDMON) on medm screens.

Result:

 BS ITMX ITMY PRM SRM MC1 MC2 MC3 UL 1.20 0.62 1.69 1.18 1.74 1.25 0.88 1.07 UR 1.21 0.54 1.50 0.99 1.77 1.64 1.46 0.31 LR 1.39 0.62 0.05 0.64 2.06 1.40 0.31 0.19 LL 1.19 0.88 0.01 0.64 1.64 1.00 0.05 1.03 SD 1.19 0.99 0.97 0.79 1.75 0.71 0.77 0.93

White: OK (0.8~1.2)
Yellow: needs to be fixed

3690   Mon Oct 11 17:31:44 2010 yutaUpdateCDSActivation of DAQ channels for 8 optics

(Joe, Yuta)

Background:
We need DAQ channels activated to measure Q-values of the ringdowns for each DOF, each optics with the Dataviewer.

What we did:
1. Activated the following DAQ using daqconfig (in /cvs/cds/rtcds/caltech/c1/scripts).
C1:SUS-XX_AASEN_IN1
C1:SUS-XX_SUSBBB_IN1
C1:RMS-YYY_AASEN_IN1
C1:RMS-YYY_SUSBBB_IN1
C1:MCS-ZZZ_AASEN_IN1
C1:MCS-ZZZ_SUSBBB_IN1
(XX=BS,ITMX,ITMY  YYY=PRM,SRM  ZZZ=MC1,MC2,MC3  AA=UL,UR,LR,LL,SD  BBB=POS,PIT,YAW)

2. Set datarate to 2048 for each DAQ.

3. Restarted fb(frame builder).

Result:
We succeeded in making DAQ channels appear in the Dataviewer signal list, but we can't start the measurement because c1mcs is still flaky.

Note:
We found that c1mcs crashes everytime when turning off all the damping servo (using "Damp" buttons on the medm screen).
It doesn't crash when all the filters are off.

3692   Mon Oct 11 22:04:28 2010 yutaUpdateCDSdamping for MCs are basically working

Background:
Even if we can't use the Dataviewer to get the time series of each 4 DOF displacements, we can still use StripTool to monitor the ringdowns and see if the damping servo is working.

What I did:
1. Excited vibration by kicking the mirror randomly (by putting some offsets randomly and turing the filters on and off randomly).

2. Turned all the servo off by clicking "ShutDown" button.

3. Turned all the servo on by clicking "Normal" button.

3. Monitored each 4 DOF displacements with StripTool and see if there are any considerably low-Q ringdown after turning on the servo.
The values I monitored are as follows;
C1:SUS_MCX_SUSPOS_INMON
C1:SUS_MCX_SUSPIT_INMON
C1:SUS_MCX_SUSYAW_INMON
C1:SUS_MCX_SDSEN_INMON  (X=1,2,3)

All the settings I used for this observation are automatically saved here;
/cvs/cds/caltech/burt/autoburt/snapshots/2010/Oct/11/21:07/c1mcs.epics

Result:
Attached is the screenshots of StripTool Graph window for each 3 MCs.
As you can see, the dampings for each DOF, each MCs are basically working.

Note:
Do NOT turn off all the damping servo by clicking "Damp" buttons or setting the SUSXXX_GAIN to 0. It crashes c1mcs.

Next work:
- check and relate the signal sign with the actual moving direction of the optics
- fix data aquisition system
- measure Q-values when the servo is on and off using DAQ and Dataviewer

Attachment 1: SUS-MC1.png
Attachment 2: SUS-MC2.png
Attachment 3: SUS-MC3.png
3697   Tue Oct 12 15:51:18 2010 yutaBureaucracySAFETYthe 40m squad received safety training from Peter

Yuta, Joonho, and Suresh received the Basic Laser Safety Training from Peter King today.

Now, we got homework.

3699   Tue Oct 12 17:42:57 2010 yutaUpdateSUSvery first measurement of Q-values for MC1

Background:
Data aquisition system is fixed, and now we can use the Dataviewer to measure Q-values of the ringdowns for each DOF, each optics.
First of all, I measured MC1 suspention damping servo for a test.

What I did:
1. Used DAQ channels activated in this entry(#3690) to see and compare the ringdowns when the damping servo is on and off with the Dataviewer.

2. Plotted the data and fitted the ringdown using this formula;
p[0]*exp(-p[1]*t)*sin(p[2]*t+p[3])+p[4]
I used python's scipy.optimize.leastsq for the fitting.

3. Calculated the resonant frequency f0 and Q-value using following formulas;
f0=2*pi*sqrt(p[1]**2+p[2]**2)
Q=f0/(2*pi)/(2*p[1])

4. For plotting, I subtracted the offset(=p[4]).

All parameters I used for this measurement are automatically saved here;
/cvs/cds/caltech/burt/autoburt/snapshots/2010/Oct/12/13:07/c1mcs.epics
(-1,0,1 for all matrix elements, GAIN=3,3,3,150 for POS,PIT,YAW,SIDE)

Result:
Attached is the plot of each 4 DOF ringdown when servo is off and on.
"servo off" means off for that DOF. Servo for the other 3 DOFs are on.

As you can see clearly, the damping servo is working.

The resonant frequencies and Q-values calculated from the fitting are as follows;

 servo off servo on f0 (Hz) Q f0 (Hz) Q POS 0.97 large 0.97 16 PIT 0.71 96 0.73 6.9 YAW 0.80 100 0.82 8.9 SIDE 0.99 large 0.99 27

Resonant frequencies and Q-values have about 1% and 10% error respectively.
I estimated it from my 2-time measurement of the POS ringdown.

Next work:
- Find and modify some scripts to optimize the matrix elements
- Calibrate the displacement
- Do the same thing for other optics

Attachment 1: MC1ringdown.png
3700   Tue Oct 12 22:06:08 2010 yutaUpdateComputerscelan-installed CentOS 5.5 on mafalda

I clean-installed CentOS 5.5(32bit) on mafalda.
No firewalls, no SELinix.

3705   Wed Oct 13 11:09:28 2010 yutaUpdateComputersclean-installed CentOS 5.5 on mafalda

Dear mafalda,

Sorry for leaving you alone.
We put ethernet cable in you. You can talk to everyone now!
We created a user "controls" correctly. (UID: 1001)
We mounted linux1:/home/cds/ to your directory /cvs/cds.

Truly yours,
Joseph Betzwieser
Yuta Michimura

Quote:

 Quote: I clean-installed CentOS 5.5(32bit) on mafalda. No firewalls, no SELinix.

Yuta has removed my ethernet connection. Help me!!!

rossa:mDV>ping mafalda
PING mafalda.martian (192.168.113.23) 56(84) bytes of data.
From rossa.martian (192.168.113.215) icmp_seq=2 Destination Host Unreachable
From rossa.martian (192.168.113.215) icmp_seq=3 Destination Host Unreachable
From rossa.martian (192.168.113.215) icmp_seq=4 Destination Host Unreachable

--- mafalda.martian ping statistics ---
5 packets transmitted, 0 received, +3 errors, 100% packet loss, time 3999ms
, pipe 3

3708   Wed Oct 13 18:01:43 2010 yutaHowToCDSeditting all the similar medm screens

(Joe, Yuta)

Say, you want to edit all the similar medm screens named C1SUS_NAME_XXX.adl.

1. Go to /opt/rtcds/caltech/c1/medm/master and edit C1SUS_DEFAULTNAME_XXX.adl as you like.

2. Run generate_master_screens.py.

That's it!!

Background:
We need MC to be locked soon, so MC suspensions should be damped well(Q~5).

What I did:
1. Set the correct filters and turn all the damping servo on.

2. Kick the optics by adding some offset into the control loop.

3. Measure the Q-value of the ringdown with my eye.

4. If Q-value seems to be around 5, go to step #5. If not, change the filter gain and go to step #2.

5. Done! Do step #1-4 for all MCs.

All parameters I used for the servo are automatically saved here;
/cvs/cds/caltech/burt/autoburt/snapshots/2010/Oct/13/20:07/c1mcs.epics

Result:
Q-values of the damping servo for all MCs are set to around 5.
Attached is the ringdown of MC2 for example.
As you can see, my eye was very rough......

Next work:
- Make a script that does steps #2-5 automatically.
I need pyNDS module installed to get data using Python.
I already wrote the rest of the script.
We'll have Leo help us install pyNDS tomorrow.

Attachment 1: MC2ringdown.png
3713   Thu Oct 14 01:09:17 2010 yutaUpdateIOOtried to lock MC but failed

(Rana, Koji, Kiwamu, Suresh, Yuta)

We attempted to lock the MC and finally got flashes of the MC, but no luck.

Tomorrow we are going to check every components one by one to make sure if everything is okay or not.

Background:
MC suspensions are well damped now.
We need MC locked for the alignment of the in-vac optics.

Issues:

These are the issues which we are going to fix.
1. DC alignment of the MC2 suspension doesn't seem to be working correctly. (see here)

We should check the satellite box and the cable connection.

The coils look like woking fine because we can kick MC2 by using each of the coils.

2. Incomplete modematching.

The spot size of the reflected light from MC1 looked like bigger.

3. beam axis of the injection light to MC1

3717   Thu Oct 14 12:53:29 2010 yutaUpdatePSLmesured PMC's visibility vs power relation

Background:
I measured the PMC's visibility vs incident power relation last week to see the thermal effect, but I didn't calibrated the laser power(see elog #3672).
So, I calibrated it on Oct 12.

Setup:

Attachment #1

What I did:
1. Calibrated the laser power(Attachment #2).
To measure the laser power, I put the Ophir power meter at just in front of "PMC REFL PD".

2. For the calculation of the visibility K, I used the following formula;
K= [1-(R1-R0)/(R2-R0)]*100
where R0, R1 and R2 are the PD outputs in voltage when laser is off, PMC locked and not locked respectively.

3. Plotted the visibility vs the incident power(Attachment #3).

Result:
Attachment #2
From the linear fit by least squares, the calibration turned out to be 1.12±0.07 mV/uW. The error of this value is calculated from assuming PD output error~1mV and laser power error~3uW for all measured value.
The largest error was from the position and the angle of the power meter probe.

Attachment #3
I used the same data I took last week(see elog #3672), but better plot.
I put the error bars for just several points. When the laser power is weak, the errors are large because of the cancellation error. When the laser power is high, the errors are estimated to be so small that you can't see it in the plot(~1%).
At the several points, I couldn't lock the PMC well and  the power of the reflected light depended on the offset voltage of the PZT.
The horizontal axis has about 6% error because of the calibration error.

Note:
Now the condition is a bit different from this measurement(NPRO temperature changed, optics moved slightly), so the visibility may be changed.

Attachment 1: PMCsetup.png
Attachment 2: PDcalib.png
Attachment 3: PMCreflect2.png
3722   Thu Oct 14 20:31:15 2010 yutaUpdateComputerspyNDS installation

EDIT by kiwamu Dec.7th ;

The Pynds package has been moved to the appropriate place:

/cvs/cds/caltech/apps/linux64/python/lib64/python2.4/site-packages

Background:
We need the python module pyNDS to get the data directly from the server using python.
Leo helped us install pyNDS today.

Installation:
1. Get pyNDS source tarball from here.

2. All you need is Boost.Python and nds2-client. See README in the pynds-0.3 directory.

3. I installed pyNDS to /cvs/cds/caltech/users/yuta/pynds

4. You have to set environment variable to import the module. For example, run;
setenv PYTHONPATH /users/yuta/pynds/lib64/python2.4/site-packages:\${PYTHONPATH}

Notes:
RPM will be available soon from Leo.

3723   Thu Oct 14 20:49:50 2010 yutaUpdateComputersautomated Q-value adjuster

Background:
Now we can use pyNDS(see elog #3722), so I wrote a python script that adjusts Q-value automatically.

What I did:
1. Wrote a python script. /cvs/cds/caltech/users/yuta/scripts/QAdjuster.py

2. Ran this script for every DOF, every MC suspension.

Result:
Following lines and attached are example output when I ran QAdjuster.py for MC3 POS.

Currently, C1:SUS-MC3_SUSPOS_GAIN is 5 Connecting.... authenticate failed: Unspecified error Connecting.... done Current GPS time is 971149410 I kicked C1:SUS-MC3_SUSPOS_OFFSET Waiting for the ringdown...... 0\ Current GPS time is 971149431 omega_0= 6.326764, Q= 11.254252, A= -53.491850, delta= 5.007821, ofset= 4349.808434 Q-value was 11.3 Set C1:SUS-MC3_SUSPOS_GAIN = 10.2311380794

Current Q-values automatically set are as follows.

 MC1 MC2 MC3 POS 4.9 4.8 5.9 PIT 6.8 5.5 4.5 YAW 6.4 5.6 5.3 SIDE 5.8 5.2 5.0

Next work:
- Modify the script so that it adjusts all the channels automatically. Now, it is one by one, trial by trial.
- Modify the script so that it automatically turns the offset switch on. Now, it must be turned on beforehand.
- Write a how-to

Attachment 1: MC3_SUSPOS.png
3742   Tue Oct 19 21:10:27 2010 yutaUpdateCDSbad filter coefficients for every suspensions!

(Koji, Yuta)

Summary:
The damping servos of the MC suspensions has not been working since yesterday. They had worked on Friday.
We found that some of the filter coefficients somehow changed from the correct value during dealing with the sampling frequency shift (from 2048Hz to 16384Hz). (see elog #3659)

What we did:
We thought that the problem occurred from the CDS update on Monday. So, we restored them using svn.
1. Went to /opt/rtcds/caltech/c1/core/advLigoRTS and ran svn update using the revision number 2125.
svn update -r 2125
2. Rebuilt all the front ends.
ssh -X c1sus
cd /opt/rtcds/caltech/c1/core/advLigoRTS
make clean-SYSNAME
make SYSNAME
make install-SYSNAME
(where SYSNAME=c1x02,c1sus,c1mcs,c1rms)
3. Restarted the front end models.
ssh -X c1sus
cd /opt/rtcds/caltech/c1/scripts
sudo startc1SYS
(where SYS=sus,mcs,rms)
4. Restarted mx_streams.
sudo /etc/restart_streams
See this wiki page for the restart procedures.

At this point we judged that the realtime system and "dataviewer" worked fine (by poking some suspensions / by measuring PSDs/TFs of the signals).

However, just restoring the RT system didn't fix the damping servos.

After that, we measured the transfer functions of the servo filters using DTT(diaggui on rosalba).
5. The filter at MC1_SUSPOS, "3:0.0" should have a cut-off frequency at 3Hz, but it was around 0.3Hz.
6. We used foton in order to look at the filter bank files (in /cvs/cds/rtcds/caltech/c1/chans). Then we found that the filter design was somehow changed to
zpk([0],[0.375],2.66666,"n")
zpk([0],[3],0.333333,"n")

Why the filter designs changed?:
We suspect that the filter designs were changed because of the replacement of sampling frequency in filter bank files(see elog #3659). We only replaced the lines like
# SAMPLING SUS_MC3_SUSPOS 2048
to
# SAMPLING SUS_MC3_SUSPOS 16384
and didn't changed the coefficients.
This may caused a problem when opening the files with foton, and foton changed 3Hz to 0.375Hz (2048/16384) and other coefficients.

Note:
The damping servo for SIDE has been working for every MCs. POS, PIT, YAW are the ones not working.

Next work:
- Fix filters for every suspensions.
There are backup files in /cvs/cds/rtcds/caltech/c1/chans/filter_archive directory, so this should help.
But I don't think just fixing filters would fix the damping servo because the filter design of MC suspensions were changed this morning and the damping had worked until Friday.

3744   Wed Oct 20 01:22:18 2010 yutaUpdateCDSfixed filters for MCs, but no damping

(Rana, Yuta)

Summary:

The damping servo for MCs has not been working since Monday.
We already found that some filter coefficients were wrong.(see elog #3742)
So, we fixed it (just for MCs now).
But still doesn't work.

What we did:
Fixed the filters for MC suspensions;
1. In /cvs/cds/rtcds/caltech/c1/chans/ directory, we replaced C1MCS.txt with ./filter_archive/c1mcs/C1MCS_101019_101927.txt.
This is the archive of the filter bank for MC suspensions, when filter designs were correct(when we hadn't opened it with foton yet).

2. Deleted all the filter coefficients.
By using emacs magical C-<space> C-x r k.

3. Loaded with foton to get correct coefficients.

We now have the correct filters, but the damping still doesn't work.

5. To confirm that the filters are now correct and the model is working correctly, we measured the transfer function between ULSEN input and ULCOIL output and compared with the calculated TF from the filter bank file (Attachment #1) .

6. To calculate the designed function, we used the following matlab scripts;
/cvs/cds/caltech/users/rana/mat/utilities/FotonFilter.m        # takes the foton file and returns the TF
/cvs/cds/caltech/users/yuta/scripts/sentocoil.m                   # calculates the total TF from SEN to COIL

Result:
As you can see from the attachment, filters seem fine now. (The red line is the measured and the blue line is the calculated function in the plot)
But the damping (for POS, PIT, YAW) still doesn't work. Why????

Next work:

- see if coils are pushing correctly
- push cable connectors further!
- check input and output filters (whitening, dewhitening)
- when fixed, use my fully updated QAdjuster.py for adjusting Q for multiple channels automatically!!

Attachment 1: Screenshot.png
3748   Wed Oct 20 21:43:25 2010 yutaUpdateCDSchecking whitening filters for MCs and messed up

(Joe, Yuta)

Background:
We found that the damping servo for MC suspensions somehow worked when we turned off the 13Hz Chebyshev filters.
But that does not meet our satisfaction, so we started checking every components.
First of all is the whitening filters.
If we turn on a digital whitening filter(WF), corresponding analog WF should turn off, and vice versa.

Reference:
See DCC #D000210 for the analog circuit of WF. WF has 3Hz zero, 30Hz pole, 100Hz pole. MAX333A bypasses analog WF when supplied +15V(HIGH).

What we did:
1. Compared the transfer function between MC2_SUSPOS_EXC and MC2_ULSEN_IN1 when digital WF on and off. When digital is on/off, analog should be off/on, so there should be difference but couldn't see.

2. We went through the simulink model and found 2 mistakes in the logic. One is the conflict with other optics. Even if we turn on/off digital WF of MC2, it didn't switched analog WF of MC2. Two is the additional bit invert (but it turned out to be our misunderstanding).

3. We (thought we) fixed it, rebuild it, and measured the TF again.(Attachment #1)

[Attached #1]
The red/blue line is when digital WF is on/off. Blue should be bigger(+10dB @ 10Hz according to (analog) WTF) than red, but it was the opposite.

4. To confirm that they are doing the opposite, I checked MAX333A input(pin#1,10,11,20) in "SUS PD Whitening Board" at 1X5-1-8B (which is for MC3) and found that switching is opposite. When I turned off/on the digital WF, MAX333A input was +15V/0V. It should be 0V/+15V.

5. Also, I found that LLSEN digital WF switch switches LRSEN analog WF and vice versa.

[Attached #2]
Transfer functions between MC2_SUSPOS_EXC and MC2_LRSEN_IN1 with;
Red: LR digital off, LL digital on
Blue: LR digital off, LL digital off
Green: LR digital on, LL digital off
As you can see, LL switch is the one which switches LR analog WF now.

Conclusion:
Currently, digital WF on/off corresponds to analog WF on/off.
Also, LL/LR digital WF switch is LR/LL analog WF switch now.

Next work:
- fix the simulink models (or wiring)
- check dewhitening filters

Schematic:
- whitening
MC1 5 PD outputs -> SUS PD Whitening Board(D000210) -> ... (digital WF=3,100:3)
MC2 5 PD outputs -> SUS PD Whitening Board(D000210) -> ... (digital WF=3,100:3)
MC3 5 PD outputs -> SUS PD Whitening Board(D000210) -> ... (digital WF=3,100:3)
D000210 has switches for bypassing analog WT(3,100:3). HIGH to bypass.
- dewhitening
(-) ... -> SOS Dewhitening Board(D000316) -> MC1,3 UL/UR/LR/LL coils
(-) ... -> SOS Dewhitening Board(D000316) -> MC1,2,3 SIDE coils
(SimDW)(InvDW) ... -> LSC Anti-imaging Board(D000186) -> Universal Dewhitening Board(D000183) -> MC2 UL/UR/LR/LL coils
D000316 has switches for bypassing 28Hz elliptic LPF. HIGH to bypass.
D000186 is 7570Hz elliptic LPFs.
D000183 has switches for bypassing dewhitening filter. HIGH to bypass.
See this wiki page for more comprehensive setup.

Attachment 1: MC2ULSEN.png
Attachment 2: MC2LRSEN.png
3757   Thu Oct 21 21:35:16 2010 yutaUpdateCDSfixed whitening filter switches

(Joe, Yuta)

Summary:
We found some mistakes in whitening filter switches yesterday(see elog #3748).
One was the mis-connection between LL/LR and the second was the bit invert.
So, we fixed it and checked that they are now switching correct by probing MAX333A.

1. LL/LR mis-connection
It occurred because UL/UR/LR/LL order is currently arbitrary and confusing.
For now, we just swap the connection(Attached #1).
In the future, we should fix all orders corresponding to the actual wiring order(UL > LL > UR > LR).

2. Bit invert
It occurred from counter-intuitive output of Contec 32 BO(See Attachment #2(taken from this wiki page)).
If "1," current goes from A to B, so MAX333A input will be 0V, which means analog WF is on.
If "0," no current, so MAX333A input will be +15V, which means analog WF is off(bypassed).

Next work:
- There are no digital WF in SDSEN inputs. So, we have to put them.
- Dewhitening filters are totally messed up now. Switches are wrong, some optics have digital DW but some doesn't, some have 28Hz elliptic LPF.......
We have to grand unify them.

Attachment 1: LLLR.png
Attachment 2: Contec23BO.png
ELOG V3.1.3-