Below are phasemaps for the tip-tilts with both tilt and RoC removed. We have not used Koji's code; but tweaked the earlier code to remove curvature.
The posted residual phase maps show circular contours since the data came with relatively low resolution in height. This is ok for what we want to do with these phase maps (i.e. simulating higher-order mode content in the PRC using Finesse). Better resolution is only required if you want to understand in detail optical scattering out of the cavity. Anyhow, the circular artifacts can be removed by first interpolating the phase maps to a higher lateral resolution, and then performing tilt and curvature subtraction. So we will soon have better looking phase maps posted. Then we should think about what type of Finesse simulation we could run. Certainly one simulation is to look at the beam shape in the PRC, but more interesting could be how sensitive the shape is to mirror alignments. The current simulation shows a mode that resembles the TEM01, but I have not yet tried to find optimal alignment of the mirrors (in simulation) to search for the TEM00 mode.
* mode matching
* epics LO HI values
* recover FSS
* make ISS working
- Put priority on the list
- Put names on the items
- Where is the CDS TO DO ==> Joe
- Remote disconnection of the greeen PDH
- What is the situation of the PD DC for the LSC PDs?
- SUS Satelite box Resister replacement ==> Jamie
- IMC mode matching ==> Jamie/Larisa
- Mechanical shutters everywhere
- SRM OPLEV Connection
- MC OAF
- Better LSC whitening boards
1) Get ETMY working - figure out why signals are not getting past the AI board (D000186) to the coils.
2) Get TDS and command line AWG stuff working
3) Get c1ass and new c1lsc (with Koji) fully integrated with the rest of the system.
4) Get CDS software instructions up to date and well organized.
5) Redo cabling and generally make it a permanent installation instead of hack job:
a) Measure cable lengths, check connectors, wire with good routes and ensure strain relief. Ensure proper labeling
b) Get correct length fiber for c1sus RFM and timing.
c) Fix up final BO adapter box and DAC boxes.
d) Make boxes for the AA filter adapters which are currently just hanging.
e) Get two "faceplates" for the cards in the back of the ETMY IO chassis so they can screwed down properly.
f) Remove and properly store old, unused cables, boards, and anything else.
6) Create new documentation detailing the current 40m setup, both DCC documents and interactive wiki.
7) Setup an Ubuntu work station using Keith's wiki instructions
1)Create simulated plant to interface with current end mass controls (say scx).
2) Create proper filters for pendulum and noise generation, test suspension.
3) Propagate to all other suspensions.
4) Working on simulated IFO plant to connect to LSC. Create filters for near locked (assume initial green control perhaps) state.
5) Test LSC controls on simulated IFO.
6) Fix c code so there's seamless switching between simulated and real controls.
- more precise F2P measurement and modify lockin simlink model (Kiwamu)
- run C1ASS to check it (Valera)
- take care of CDS (Joe)
- MC mode matching (Jenne/Koji)
- RF stuff (Suresh)
- mode matching for doubling crystal at PSL table (low priority)
- OPLEV (low priority)
- update the noise spectra of green locking
- make noise budgets
. mode matching for MC (Jenne/Koji)
. mode matching for doubling crystal on PSL table (Suresh/Koji)
. f2p adjustment (Kiwamu)
. fix daq and CDS issues (Joe)
. increase oplev gain (low priority)
. make ITMY camera nicer (Steve)
. c1ass simlink model (Valera/Joe)
. Bounce Roll notches (Suresh)
. align everything (at first green beam, then X arm cavity and finally IR beam)
. update the noise spectrum of the green locking
. estimate the noise from angle to length coupling
PMC locked manually and PRM sus damping restored.
Here's an update of the suspensions, after yesterdays in-vacuum work and OSEM tweaking:
pit yaw pos side butt
UL 0.828 1.041 1.142 -0.135 1.057
UR 1.061 -0.959 1.081 -0.063 -1.058
LR -0.939 -0.956 0.858 -0.036 0.849
LL -1.172 1.044 0.919 -0.108 -1.035
SD 0.196 -0.024 1.861 1.000 0.043
pit yaw pos side butt
UL 1.141 0.177 1.193 -0.058 0.922
UR 0.052 -1.823 0.766 -0.031 -0.974
LR -1.948 -0.082 0.807 -0.013 1.147
LL -0.859 1.918 1.234 -0.040 -0.957
SD -1.916 2.178 3.558 1.000 0.635
pit yaw pos side butt
UL 1.589 0.694 0.182 0.302 1.042
UR 0.157 -1.306 1.842 -0.176 -0.963
LR -1.843 -0.322 1.818 -0.213 0.957
LL -0.411 1.678 0.158 0.265 -1.038
SD 0.754 0.298 -3.142 1.000 0.053
[Anamaria / Kiwamu]
The incident beam pointing was improved by using PZT1 and PZT2.
With some triggers the lock of PRMI became smoother.
For the DRMI lock, the MICH and SRCL signals on AS55 are not quite decoupled, so we should find cleaner signals for them.
(what we did)
+ locked the Y arm
+ aligned incident beam by using PZT1(#5450) and PZT2. The spot positions on ITMY and ETMY are now well-centered.
+ tried activating C1ASS but failed. It needs some gain changes due to the new PZT1 response.
+ locked the X arm
+ aligned the TRX PD (Thorlab signal PD) and set the trigger.
+ C1ASS also doesn't work for the X arm
+ realigned the PRM and BS oplevs. the PRM oplev was clipped at a steering mirror on the optical bench
+ locked PRMI and aligned the PRM mirror such that the optical gain was maximized
+ optimized the demod phase of AS55 and REFL11
+ checked the UGF of the MICH and PRCL lock. The UGF of MICH is about 100Hz with gain of -20, and the UGF of PRCL was 85 Hz with gain of 0.1
+ adjusted the output matrix such that the MICH control doesn't couple into the PRCL control.
+ set the triggers for the MICH and PRCL control to make the lock acquisition smoother.
+ tried locking DRMI and it was sort of locked. However the SRCL signal showed up a lot in AS55_Q, where the MICH signal is extracted.
I think this week is going to be an "alignment week".
The goal is to get a good alignment on X arm for both the green and the IR beam in order to reduce a2l couplings.
Today's missions are :
- fixing the oplev channel names (see here)
- fixing the oplev gain issue (see here)
- engage the oplev servos
- f2p adjustment
- make a realtime lockin model for the f2p measurement and the dithering technique
- alignment of the MC incident beam (because we installed a new PMC this morning)
- manual alignment of the IR beam by steering PZT1 and PZT2 (this procedure will be replaced by an automatic way soon)
- bounce roll filters (see here)
0. have a coffee and then dress up the clean coat.
1. level the MC table
2. lock and align MC
3. run A2L script to see how much off-centering of the spots
4. steer the periscope mirror <--- We are here
5. move the pick off mirror which is used for monitoring of MCT CCD
6. check the leveling and move some weights if it's necessary
7. shut down
[Steve / Suresh / Kiwamu]
90 % of unused video cables have been removed.
Still a couple of video cables are floating around the video MUX. They will be removed in the next week's session.
The main goal of today is to extract the pick-off beams
Today's menu :
+ If necessary steer ETMs and ITMs to make the X and Y green beam flashing.
+ Open the IOO and OMC chamber and lock MC.
=> cover the place of the access connector by a large piece of aluminum foil. It will give a robust lock of MC.
+ Check the beam pointing down to Y arm by looking at the ETMY face camera.
=> If it's necessary align PZT1 and PZT2 from EPICS to make the IR beam flashing in the X arm.
+ Align BS and let the beam hit the center of ETMX to make the X arm flashing.
=> These alignment procedure will automatically gives us the MICH fringes on the AS CCD camera.
+ Rotate the SRM tower to get the SRMI fringes on the AS CCD camera.
=> This is because the required amount of the YAW correction on SRM is currently beyond the range of the DC bias.
+ Align PRM to get the PRMI fringes on AS CCD camera. Also make sure the beam comes back to the REFL CCD camera.
+ Lock the PRC to make POP/POX/POY bright enough.
=> Probably the REFL11 RFPD needs more power. To increase the power, just rotate the HWP, which is sitting before the RFPDs on the AS table.
=> If the signal on AS55 is too small, we can use REFL11_Q or REFL55 for the MICH lock.
+ OR inject and align the ABSL laser to make those pick-off beams bright enough.
=> This case we don't have to make the DRMI exactly on the resonance, what we need is just the DRMI flashing.
+ Align necessary optics for those pick-off beams.
=> In our definition (aLIGO definition) POP is the beam propagating from BS to PRM. Don't be confused by another one, which propagates from PRM to BS.
+ Steer two mirrors on the ETMY table for aligning IPANG. Also, steer some mirrors on the BS table for IPPOS.
=> IPANG has already reached the ETMY table, so ideally we don't have to steer a mirror on the BS table.
=> IPPOS/ANG are very visible with a sensor card.
+ Align some oplevs.
=> This work is relatively independent from the other tasks. Steve can take care of it.
+ Adjust the OSEM to their mid-range.
=> This work can be done anytime, but everytime we have to recover the alignment of the interferometer.
>If necessary steer ETMs and ITMs to make the X and Y green beam flashing.
Green is now flashing in both X and Y arms
>Open the IOO and OMC chamber and lock MC.
Open, and cover in place. MC is flashing and locking.
Kiwamu aligned things for me, and I rotated the SRM tower so that the reflected beam was pretty much totally overlapping the incident beam. The SRC was aligned to make sure things were good. Now the DC bias for SRM Yaw is ~1.4, so we're totally good.
To rotate SRM, Jamie had the idea of using 2 screws so I could push the tower on one side, and back off the screw an equal amount on the other side and push the tower to be touching both screws again, to ensure that I was rotating about the center of the tower and wasn't introducing any Pos action.
While I was at it, I also moved the OSEM connector tower back to its normal place on the table, so it's not in the way of oplev beams. It had been moved previously to accommodate ITMY near the door.
Our toilets were replaced by a green Gerber 1.6 gpf ( 6 lpf ) last week.
Electrician is coming to fix one of the fluorenent light fixture holder in the east arm tomorrow morning at 8am. He will be out by 9am.
The job did not get done. There was no scaffolding or ladder to reach troubled areas.
The lock of PRMI wasn't so robust although it could stay locked for more than 10 minutes.
There have been 2-3Hz spikes in everywhere. It needs to be investigated.
+ Diagnosis on the suspensions.
+ Check the beam centering on the RFPDs.
+ Check the f2a filters on PRM and BS.
+ Health check of the suspensions by locking some cavities and measuring the noise spectra for comparison.
+ Trying to use another signal port other than AS55.
The attached picture below is an example of the REFLDC and POXDC signals in time series.
This was when PRCL and MICH were locked by REFL33_I and AS55_Q respectively.
Note that when PRMI is unlocked, REFLDC goes to ~ 5000 counts and POXDC goes within ADC noise of ~ 1 counts.
According to the POP camera it looked like something was oscillating in the YAW direction which coincided with the spikes.
I tried finding any suspicious angular motions in the ITMs, BS and PRM olevs, but none of them showed the 2-3 Hz feature.
I found that all the Heliax cables landing on the bottom of 1Y2 were too loose.
Due to this loose connection the RF power at 55 MHz varies from -34 dBm to 3 dBm, depending on the angle of the Heliax's head.
The looseness basically comes from the fact the black plate is too thick for the Heliax cable to go all the way. It permits the Heliax's heads to rotate freely.
What we should do is to make countersinks on the black plate like this:
The countersink gives rise to another problem when we mount the N-type-to-SMA bulkhead adaptor. As we are making a circular hole in the plastic strip (instead of a hole with two flat sections) the adaptor is free to turn when we tighten it with a wrench. We currently hold the smooth circular part on the other side with a gripping pliers and while tightening. If that part disappears into the countersink (as seen in the pics) we will not be able to tighten the adaptor sufficiently and consequently we will also not be able to get the heliax connector to be tight.
A better solution would be to use the 1/4-inch plastic L-angle beam which Steve has used on the AS table. In addition to solving this loose connector problem, the beam is also more rigid than the plastic strip.
New Wiha 28504 torque wrench for SOS wire clamping. It's range 7.5 - 20 in-lb in 0.5 steps [ 0.9 - 2.2 Nm ] Audible and perceptible click when the pre-set torque has been attained at ±6% accuracy.
The new ETMX sus wire torqued to ~ 11.5 in-lb [1.3 Nm ]
Gautam and Steve,
The clamp's left side was jammed onto the left guide pin. It was installed slit facing left. Gautam had to use force to remove it. The clamp should move freely seating on the guide rods till torque aplied. Do not move on with the hanging of optic with a jammed clamp. Fix it.
Never use force as you are hanging - aligning optic. The clamp is in the shop for resurfacing and slit opening.
Few 1/4 -20 socket cap head screw with washers were tested for optimum torque.
QJR 117E Snap On torque wrench was used. I found that 40 lb in was enough.
These numbers will varie with washers, material it's going into and so on!
The standard among high-strength fasteners, these screws are stronger than Grade 8 steel screws. They have a minimum tensile strength of 170,000 psi. and a minimum Rockwell hardness of C37. Length is measured from under the head.
Inch screws have a Class 3A thread fit. They meet ASTM A574.
Black Oxide—Screws have been heat-treated for hardness, which results in a dark surface color.
Rana is next to calibrate his feelings and declare the right number.
Than Koji....and so on
Once we a number, than I buy more torque wrenches to fit it.
For 1/4-20 bolts made of 18-8 Stainless Steel, the recommended torque varies from 65-100 inch-pounds, depending upon the application, the lubrication, how loose the bolt is, if there's a washer, etc.
For our case, where we are going into a tapped, ferromagnetic stainless table, its less clear, but it will certainly by in the 60-80 range. This is close to the 5-6 foot-lbs that I recommended on Wednesday.
I've ordered 3 torque wrenches with 1/4" drive so that we can have one at each end and one in the toolbox near MC2. We'll indicate the recommended torque on there so that we can tighten everything appropriately.
Tonight I measured seismic noise coupling to beam spot on PR2. There is coherence of 0.9 from X to PIT and Y to YAW around the stack resonances. TF was fited using vectfit and put into static matrix of oaf in the elements T240X -> PRM PIT, T240Y -> PRM YAW. I think we should actuate on the error point of the PRM OL but I decided not to go for a model change tonight. Data from seismometers and POP QPD was obtained during the UTC time 04:06:00 - 04:50:00 when PRMI was locked on sideband
Interferometer was locking rather robustly and every lock lasted on the everage of 3 minutes. During these lock periods I incresed bandwidth of optical lever servos of BS and test masses from 4Hz up to 10Hz and then closed transmission QPD loops. It seems from the camera that lock losses correspond to strong motion of the beam on pop camera. Scripts that change OPLEV bandwidth are in /users/den "increase_ol_bandwidth.sh" "decrease_ol_bandwidth.sh". Script "engage_qpd_servos" turns off ETM oplevs and turns on ETM -> trans QPD servos. These scripts can be copied to locking directrly if are useful.
Please, note that transition from 3f to 1f should still be tuned. Only PRCL was stably controlled using 1f so far
Bob replaced the tipseal in an other drypump and I swapped it in. TP3 turbo is running again, it's foreline pressure is 40 mTorr. The RGA is still off
Does anyone know if this master file is the real thing that's in use now? Are we really using a file called tpchn_C1_new.par? If anyone sees Alex, please get to the bottom of this.
"Yes. This master file is used."
Now that both end transmission QPDs have the line filters, I aligned them.
I locked and aligned the IR using the ASS, then went to each end table and put the beam in the center of the QPD.
I have assembled the circuit and the control box for the quadrant magnetic levitation yesterday. The final setup is shown
in the figure below:
Due to my carelessness, I I connected the wrong ends of the power supply. I damaged 4 op-amp and one voltage
regulator during this assembly. This stupid mistake spent me several hours to fix, and I got a bitter lesson;-(
Afterwards, I replaced those op-amps and reconnected the power supply . Kiwamu helped me and we measured
the transfer function of this circuit. The transfer function agrees with the specification in the schematics which
has a integrator below 1 Hz and a differentiator from 5 to 20 Hz. The bode plot for the measured transfer function
is the following:
Today I tested the photodetector parts and found that there is a mysterious oscillation. Whenever I connect the
photodector input A of the circuit (as indicated in the figure below),
the output of the op-amp has a 500k Hz oscillation shown up in the oscilloscope.This happens even A is disconnected from
the photodetector and connected to an open end wire. I don't know how to eliminate it, and its amplitude is so large (peak to
peak is around 2.5 V) which completely dominates the photodetector output. Does anybody has some ideas? Thanks.
1. Why do all of the BNCs have no GND connection? Each should have the individual cables to the ground. Each signal line and the corresponding ground line should be twisted together.
2. This looks the (usual) oscillation of the V-I conversion stage but I can't tell anything as I don't have the circuit diagram of the whole circuit.
3. In a certain case, putting some capacitance at the feedback may help. Read P.11 of the data sheet of LT1125. Try to put some capacitors from 20pF to some larger one whether it changes the situation or not. I suppose the bandwidth of your sensor can be ~1kHz. So putting a capacitance less than 10nF still has no effect to the servo.
1. They are all connected to the box which has a single connection to the board ground. If I connect each of them to the ground, there would be many small loops
of ground. Of course, I should have replaced all the connectors such that the they are disconnected to the box as point out by Robert.
2. The oscillation disappears after I add 5 nF capacitor in parallel to the existing resistor. Thank you very much for pointing this out.
1. Yes. That is the bad. You should eventually replace the BNCs to the isolated ones.
2. OK. I like to emphasize again that everyone works on electronics should read data sheets more carefully and seriously because they have many important practical instructions to exploit full performance of the components.
[Koji and Kiwamu]
We took transfer functions (TF) from the angle excitations at ETMX and ITMX to the green beat note signal (i.e. angle to length TF).
It turned out that the coupling from ETMX_PIT is quite large.
I wonder how f2p of the ETMX changes this coupling. We'll see.
The plot above shows a set of the transfer functions from the angle excitation to the green beat note.
Note that the y-axis has not been calibrated, it is just a unit of counts/counts.
You can see that the TF from ETMX_PIT to the beat (red cruve) is larger than the others by about a factor of 10 over most of the frequency range.
This means that any PIT motions on ETMX can be coupled into the green beat signal somewhat over the wide frequency range.
It looks having a resonance at 1.5 Hz, but we don't exactly know why.
At that time the coil gains on only ITMX were tuned by applying f2p filters, but ETMX wasn't because of a technical reason coming from epics.
- - - - measurement conditions
* PSL laser was locked to X arm by feeding back the IR PDH signal to MC2.
* the green laser was locked to Xarm as usual.
* took the green beat note signal (approximately 0 dBm) into Rana's MFD with the cable length of about 6 m.
* the output from the MFD was connected to XARM_COARSE channel without a whitening filter.
* excitation signal was injected into either ASC_PIT or ASC_YAW. The excitation was Gaussian noise with frequency band of 10 Hz and amplitude of 300 counts.
* only ITMY had the f2p filters, which balance the coil gains all over the frequency.
I've started to create channels and an medm screen to monitor the errors that occur during the transmission through the RFM model. The screen will show the amount of lost data per second for each channel.
Not all channels are ready yet. For created channels, number of errors is 0, this is good.
I had to do a reboot + burt restore of c1psl today. It was unresponsive and I couldn't get the PMC to lock. I also had to slightly realign the PMC, and the IMC was too misaligned for the autolocker to catch lock. Adjusting it manually, it was predominantly MC1 PIT that was off. The YARM locked on a 10 mode and had to be aligned manually as well.
I left a script running on Donnatella that tilts ETMX and thus moves the beam on ITMX. I'm monitoring the transmitted power to evaluate sane thresholds for the demodulation offsets in a lossmap measurement. The script will return the IFO to normal after it is done and will take <2 hours to complete (no real clue, but there's no way it takes longer than that for ~50 datapoints).
Unfortunately it looks like there may be a problem with trend data, though. If I try to retrieve 1 minute of "full data" with dataviewer for channel C1:SUS-ITMX_SUSPOS_IN1_DQ around GPS 1019089138 everything works fine:
Connecting to NDS Server fb (TCP port 8088)
T0=12-04-01-00-17-45; Length=60 (s)
60 seconds of data displayed
but if I specify any trend data (second, minute, etc.) I get the following:
Connecting to NDS Server fb (TCP port 8088)
Server error 18: trend data is not available
datasrv: DataWriteTrend failed in daq_send().
T0=12-04-01-00-17-45; Length=60 (s)
No data output.
Alex warned me that this might have happened when I was trying to test the new daqd without first turning off frame writing.
Alex told me that the "trend data is not available" message comes from the "trender" functionality not being enabled in daqd. After re-enabling it (see #6555) minute trend data was available again. However, there still seems to be an issue with second trends. When I try to retrieve second trend data from dataviewer for which minute trend data *is* available I get the following error message:
Connecting to NDS Server fb (TCP port 8088)
No data found
T0=12-04-04-02-14-29; Length=3600 (s)
No data output.
Awaiting more help from Alex...
I would like to suggest a trial run on these....Ergomates and the cleanboot!
REPLY by JCD: Are these going to trap dirt and be impossible to clean though? The nice thing about Crocs and the giant flip flops is that they are solid and if they get dirty you can do a quick wipedown, and they're good as new.
The Cleanboot is washable and reusable!
(Suresh, Kiwamu, Yuta)
Lastnight, we locked the MC and tried angle to length(A2L) measurement using my new python script (see elog #3863).
Although the amount of position script shows looks too big, the response seemed somewhat reasonable.
Using the results of A2L measurement, we managed to reduce the displacement from the center of the MC optics, but we lost TEM00 mode after changing the incident beam direction and PMC lock got off .
We restored the alignments and now it is 00, but the displacements got worse than the best we achieved last night.
I think I have to rethink how to align MC. Even if I could somehow get exact position of the beam, how to align the beam to the center of the optics?
What we did:
1. At first we tried to align by changing the direction of the incident beam. We found that A2L.py shows opposite direction(lower <-> upper). It was because of my misunderstanding and we agreed that the direction is opposite.
2. Aligned MC optics without changing the direction of the incident beam. We could understand which directions decrease the displacements from the center, and managed to decrease them.
3. There seemed to be a limit in aligning the MC optics without changing the incident beam direction. So, we started to change the incident beam direction again by steering mirrors at PSL table.
4. During the change, PMC lock got off. We restored it, but we lost MC's 00 mode.
5. We restored MC 00 mode, and measured the final A2L. The result was worse than we achieved by step #2.
The final result from last night using my script was as follows;
% is the length compared to the half of coil to coil length. Low / right are positive.
We can see the beam position got better by looking at the monitor from MC2, and the A2L measurement result agrees with that.
Here's some pictures from the measurement last night. Each plots are not taken at the same time.
(It was painful using slow computers to make measurement. The StripTool graph shows straight lines when computers got frozen)
- Plan a strategy
- The script needs self-estimation of the measurement. Now, the script fits the plot assuming every data has the same error.
- When the beam is near the center, the signal gets smaller and the result will be unreliable. One thing I can do is to change TO_COIL gains radically so that the axis of rotation go far from the center.
(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.
MC suspensions are well damped now.
We need MC locked for the alignment of the in-vac optics.
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
We tried to see the Yarm length change using Yarm green beat note. The beat note is still puny, so we put an extra amplifier. We saw something, but still can't control the arm length with ALS.
What we did:
1. Aligned Y arm and PSL green optics as usual.
2. By changing the temperature of the PSL laser with C1:PSL-FSS_SLOWDC, we find small beat note when
PSL laser temperature on display: 30.59 deg C (PSL HEPA 100%)
C1:PSL-FSS_SLOWDC = 5.2100
Y end laser "T+": 34.049 deg C
Y end laser "ADJ": 0
Y end laser measured temperature: 34.68 deg C (*)
C1:GCY-SLOW_SERVO2_OFFSET = 29425
(*) Measured using diagnostic output on the back of the laser controller(Lightwave 125/6-OPN-PS) - between pins 2(GND) and 4. Calbration factor is 10 degC/V.
3. The peak height right after the amplifier on the Y green beat PD was ~ -48dBm, so we put another amplifier (and attenuator) because the beat note which goes into the frequency divier should be -30 dBm to +7 dBm. After we put the amplifier, the peak height was ~ -23 dBm.
4. We could see the C1:ALS-BEATY_COARSE_I_ERR ringing down, when opening and closing the control room door, which may introduce Y arm length change(screenshot of dataviewer below). But we are still not sure if we are actually getting the Y arm length signal because closing and opening Y end green shutter doesn't make difference on C1:ALS-BEATY_COARSE_I_ERR. The ring down was seen when we turned on the unWhiten filters in C1:ALS-BEATY_COARSE filter modules.
5. Tried to hold Y arm length with ALS, but couldn't.
Red ones are the ones we added or changed.
Dataviewer is so slow and flakey now.
I made a new medm screen for the triggering logics. Have fun.
I put a button on C1LSC.adl to invoke this screen.
It will be quite useful for the Y arm locking, for instance we can do a triggered locking and the maximization of the intracavity power.
We have a Trillium for several days from Vladimir. I've put seismometer inside the foam box on linolium. I was not able to level the seismometer on granite as this Trillium does not have level screws. Does anybody know where they are? Readout box stands on the foam box as seismometer cable is short (~2 meters).
Cables go to STS1 inputs (7-9) on ADC 3.
I was asked by Koji to point out where a schematic of the triple resonant circuit is.
It seems that I had posted a schematic of what currently is installed (see elog 4562 from almost 4 yrs ago!).
(Some transfomer story)
Then I immediately noticed that it did not show two components which were wideband RF transformers. In order to get an effective turns ratio of 1:9.8 (as indicated in the schematic) from a CoilCrfat's transformer kit in the electronics table, I had put two more transformers in series to a PWB1040L which is shown in the schematic. If I am not mistaken, this PWB1040L must be followed by a PWB1015L and PWB-16-AL in the order from the input side to the EOM side. This gives an impedance ratio of 96 or an effective turns ratio of sqrt(96) = 9.8.
(An upgrade plan document)
Also, if one wants to review and/or upgrade the circuit, this document may be helpful:
This is a document that I wrote some time ago describing how I wanted to make the circuit better. Apparently I did not get a chance to do it.