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ID Date Author Type Category Subject
1925   Tue Aug 18 15:52:27 2009 JenneUpdatePSLMZ
I tweaked up the MZ alignment.  The reflection had been around 0.550, which kept the MEDM indicator green, but was still too high.  I fiddled with BS1, and a little bit with BS2.  When I had the doors of the PSL table open, I got as low as 0.320.  When I closed up and came back to the control room, the MZ refl had drifted up to 0.354.  But it's good again now.

In the future, mirrors shouldn't be so close together that you can't get at their knobs to adjust them No good.  I ended up blocking the beam coming out of the PMC to prevent sticking my hand in some beam, making the adjustment, then removing the dump.  It worked in a safe way, but it was obnoxious.

1926   Tue Aug 18 19:57:47 2009 rana, JenneUpdatePSLMZ

- we finished the MZ alignment; the contrast is good.

- we did the RFAM tuning using a new technique: a bubble balanced analyzer cube and the StochMon RFPD. This techniques worked well and there's basically no 33 or 166 RFAM. The 133 and 199 are as expected.

- the MC locked right up and then we used the periscope to align to it; the transmission was ~75% of max before periscope tuning. So the beam pointing after the MC should be fine now.

- the Xarm locked up with TRX = 0.97 (no xarm alignment).

If Rob/Yoichi say the alignment is now good, the we absolutely must center the IOO QPDs and IP POS and IP ANG and MC TRANS  today so that we have good references.

-----------------------------------

The first photo is of our nifty new setup to get the beam to the StochMon PD.  The MZ transmitted beam enters the photo from the bottom right corner, and hits the PBS (which we leveled using a bubble level).  The P-polarization light is transmitted through the cube, and the S-polarization is reflected to the left.  The pure S-polarized light hits a Beam Splitter, which we are using as a pickoff to reduce the amount of light which gets to the PD.  Most of the light is dumped on an aluminum dump.  The remaining light hits a steering mirror (Y1 45-S), goes through a lens, and then hits the StochMon PD.  While aligning the MZ to maximize visibility, we look at the small amount of P-polarized light which passes through the PBS on an IR card, and minimize it (since we want to be sending purely S-polarized light through the EOMs and into the MC).

The second photo is of a spectrum analyzer which is directly connected to the RF out of the StochMon PD.  To minimize the 33MHz and 166MHz peaks, we adjust the waveplates before each of the EOMs, and also adjusted the tilt of the EOM holders.

The final photo is of the EOMs themselves with the Olympus camera.

Once we finished all of our MZ aligning, we noticed that the beam input to the MC wasn't perfect, so Rana adjusted the lower periscope mirror to get the pointing a little better.

The MZ refl is now at 0.300 when locked.  When Rana reduced the modulation depth, the MZ refl was about 0.050 .  Awesome!

Attachment 1: MZ_RFAMmon_setup_small.jpg
Attachment 2: MZ_RFAMmon_SpecAnalyzer_small.jpg
Attachment 3: MZ_EOM_IRrefl2_small.jpg
1928   Wed Aug 19 17:11:33 2009 JenneUpdateIOOQPDs aligned

 Quote: If Rob/Yoichi say the alignment is now good, the we absolutely must center the IOO QPDs and IP POS and IP ANG and MC TRANS  today so that we have good references.

IOO_QPD_POS,    IOO_QPD_ANG,    MC_TRANS,    IP_POS, IP_ANG    have all been centered.

Also, the MCWFS have been centered.

I'm now working on making sure beam is hitting all of the RF PDs around.

1929   Wed Aug 19 18:02:22 2009 JenneUpdateLSCRF PDs aligned

All of the LSC RF PDs have been aligned.  I didn't really change much of anything, since for all of them, the beam was already pretty close to center.  But they all got the treatment of attaching a Voltmeter to the DC out, and adjusting the steering mirror in both pitch and yaw, finding where you fall off the PD in each direction, and then leave the optic in the middle of the two 'edges'.

Before aligning each set (PO, Refl, AS), I followed the procedure in Rob's new RF photodiode Wiki Page

Also, for superstitious reasons, and in case I actually bumped them, I squished all of the ribbon cable connectors into the PDs, just in case.

1930   Wed Aug 19 23:57:35 2009 robUpdateLockingreport

locking work proceeding apace tonight.

diagonalized DRM with setDDphases & senseDRM

initial locks are fairly quick, aqstep script succeeds reliably.

first part of cm_step (handoff CARM-> MCL) usually works.

tuning up later parts of cm_step (presumably due to optical gain changes resulting from MOPA decline).

got to arm powers ~60.

1932   Fri Aug 21 17:05:04 2009 JenneUpdateGeneralrestarted the elog

[Kevin, Jenne]

Kevin's awesome final report/elog entry was so awesome that it crashed the elog.  It has been restarted.  We're going to put his pictures and documentation in the wiki, with a link from the elog to prevent re-crashing.

1935   Fri Aug 21 18:37:16 2009 JenneUpdateGeneralTransfer function of Mode Cleaner Stacks

Using free-swinging Mode Cleaner OSEM data and Guralp seismometers, I have taken transfer functions of the Mode Cleaner stacks.

During this experiment, the MC was unlocked overnight, and one Guralp seismometer was underneath each chamber (MC1/MC3, and MC2).  Clara will let me know what the orientation of the seismometers were (including which seismometer was underneath which chamber and what direction the seismometer axes were pointing), but for now I have included TFs for every combination of suspension motion and seismometer channels.

I combined the 4 OSEM channels for each optic in POS and PIT, and then calibrated each of my sus channels using the method described in Kakeru's elog entry 1413. Units are meters for POS, and radians for PIT.  I also calibrated the guralp channels into meters.

The traces on each plot are: MC_{POS or PIT} / Guralp_{1 or 2}_{direction}.  So each plot shows the coupling between every seismometer direction and a single mirror direction.  The colors are the same for all the plots, ie the gold trace is always Gur1Z.

Attachment 1: TF_osems_guralps.png
1938   Tue Aug 25 00:35:04 2009 ranaUpdateGeneralTransfer function of Mode Cleaner Stacks

Looks like all of the accelerometers and seismometers have been disconnected since early AM last Monday when Clara disconnected them for her sensor noise measurement.

Attachment 1: Untitled.png
1943   Tue Aug 25 18:42:42 2009 steveUpdatePSLreference cavity temp box temporarly out of order

 Quote: The PSL Temperature Box (D980400-B-C, what kind of numbering scheme is that?) modified at LHO/LLO ~8 years ago to have better resolution on the in-loop temperature sensors. I haven't been able to find a DCN / ECN on this, but there's an elog entry from Hugh Radkins here.  I'm also attaching the PDF of the latest drawing (circa 2000) from the DCC. The schematic doesn't show it, but I am guessing that the T_SENSE inputs are connected to the AD590 chips, and that 4 of these are attached somehow to the RefCav can. IF this is true, I don't understand why there are input resistors on the LT1125 of U1; the AD590 is supposed to be a current source ? Peter King is supposed to be coming over to work on this today so whoever spots him should force/cajole/entice him to elog what he's done. Film him if necessary.   I also think R1-8 should be swapped into metal film resistors for stability. The datasheet says that it puts out 1 uA/K, so the opamps put out 10 mV/K. J8 and JP1 should be shorted to disable both the tidal and VME control input. Both are unused and a potential source of drift.

Peter King is updating our temp box as Hugh did at Hanford Oct.22 of 2001 I still have not seen an updated drawing of this.

The LT 1021-7 reference chip will arrive tomorrow morning. This modification should be completed by noon.

** The link to the DCN from Hugh is here in the DCC.

1944   Tue Aug 25 21:26:12 2009 AlbertoUpdateComputerselog restarted

I just found the elog down and I restarted it.

1945   Tue Aug 25 21:36:28 2009 AlbertoUpdatePSLreference cavity temp box temporarly out of order

Is that the reason of the PSL craziness tonight? See attachment.

Attachment 1: 2009-08-25_PSLtrend.png
1946   Tue Aug 25 21:55:11 2009 ranaUpdatePSLreference cavity temp box temporarly out of order

There's no elog entry about what work has gone on today, but it looks like Peter took apart the reference cavity temperature control around 2PM.

I touched the reference cavity by putting my finger up underneath its sweater and it was nearly too hot to keep my finger in there. I looked at the heater power supply front panel and it seems that it was railed at 30 V and 3 A. The nominal value according to the sticker on the front is 11.5 V and 1 A.

So I turned down the current on the front panel and then switched it off. Otherwise, it would take it a couple of days to cool down once we get the temperature box back in. So for tonight there will definitely be no locking. The original settings are in the attached photo. We should turn this back on with its 1A setting in the morning before Peter starts so that the RC is at a stable temp by the evening. Its important NOT to turn it back on and let it just rail. Use the current limit to set it to 1 A. After the temperature box is back in the current limit can be turned back up to 2A or so. We never need the range for 3A, don't know why anyone set it so high.

Attachment 1: Untitled.png
Attachment 2: rc-heater.jpg
1948   Wed Aug 26 14:45:14 2009 steveUpdatePSLPSL-FSS_RCTEMP of 4 years

The reference cavity vacuum chamber temp is plotted starting Feb 22 of 2005

This plot suggest that the MINCO temp controller is not working properly.

Attachment 1: refcavtemp.jpg
1949   Wed Aug 26 15:42:17 2009 AlbertoUpdatePSLreference cavity temp box temporarly out of order

 Quote: There's no elog entry about what work has gone on today, but it looks like Peter took apart the reference cavity temperature control around 2PM. I touched the reference cavity by putting my finger up underneath its sweater and it was nearly too hot to keep my finger in there. I looked at the heater power supply front panel and it seems that it was railed at 30 V and 3 A. The nominal value according to the sticker on the front is 11.5 V and 1 A. So I turned down the current on the front panel and then switched it off. Otherwise, it would take it a couple of days to cool down once we get the temperature box back in. So for tonight there will definitely be no locking. The original settings are in the attached photo. We should turn this back on with its 1A setting in the morning before Peter starts so that the RC is at a stable temp by the evening. Its important NOT to turn it back on and let it just rail. Use the current limit to set it to 1 A. After the temperature box is back in the current limit can be turned back up to 2A or so. We never need the range for 3A, don't know why anyone set it so high.

While Peter King is still working on the reference cavity temperature box, I turned the power supply for the reference cavity's heater back on. Rana turned it off last night since the ref cav temperature box had been removed.

I just switched it on and turned the current knob in the front panel until current and voltage got back to their values as in Rana's picture.

I plan to leave it like that for half an hour so that the the cavity starts warming up. After that, I'll turn the current back to the nominal value as indicated in the front panel.

1951   Wed Aug 26 16:11:41 2009 AlbertoUpdatePSLreference cavity temp box temporarly out of order

It turned out that half an hour was too long. In less than that the reference cavity temperature passed the critical point when the temperature controller (located just below the ref cav power supply in the same rack) disables the input power to the reference cavity power supply.

The controller's display in the front shows two numbers. The first goes with the temperature of the reference cavity; the second is a threshold set for the first number. The power supply gets enabled only when the first number comes under the threshold value.

Now the cavity is cooling down and it will take about another hour for its temperature to be low enough and for the heater power supply to be powered.

1952   Wed Aug 26 16:31:34 2009 steveUpdatePSLreference cavity temp box temporarly out of order

 Quote: It turned out that half an hour was too long. In less than that the reference cavity temperature passed the critical point when the temperature controller (located just below the ref cav power supply in the same rack) disables the input power to the reference cavity power supply. The controller's display in the front shows two numbers. The first goes with the temperature of the reference cavity; the second is a threshold set for the first number. The power supply gets enabled only when the first number comes under the threshold value. Now the cavity is cooling down and it will take about another hour for its temperature to be low enough and for the heater power supply to be powered.

The cavity temp cooled below SP2 set point 0.1  The Minco SP1 (present temp in Volts) now reading -0.037 so DC power supply was turned on and set to 12V 1A

1954   Wed Aug 26 19:58:14 2009 Rana, AlbertoUpdatePSLReference Cavity Temperature Control: MINCO PID removed

Summary: This afternoon we managed to get the temperature control of the reference cavity working again.

We bypassed the MINCO PID by connecting the temperature box error signal directly into EPICS.

We couldn't configure the PID so that it worked with the modified temperature box so we decided to just avoid using it.

Now the temperature control is done by a software servo by using the channel C1:PSL-FSS_MINCOMEAS as error signal and driving C1:PSL-FSS_TIDALSET (which we have clip-doodle wired directly to the heater input).

We 'successfully' used ezcaservo to stabilize the temperature:

ezcaservo -r C1:PSL-FSS_MINCOMEAS -s 26.6 -g -0.00003 C1:PSL-FSS_TIDALSET

We also recalibrated the channels:

C1:PSL-FSS_RMTEMP

C1:PSL-FSS_RCTEMP

C1:PSL-FSS_MINCOMEAS

with Peter King on the phone by using ezcawrite (EGUF and EGUL) but we didn't change the database yet. So please do not reboot the PSL computer until we update the database.

More details will follow.

Attachment 1: rc.png
1955   Thu Aug 27 12:34:48 2009 YoichiUpdateLockingup to arm power 70
Last night, I tried to run locking scripts.
The power went up to 70 a couple of times .
Then it failed to switch to RF CARM.
I was too tired at that time to figure out what is the problem with the switching.
But it seemed to me that the problem could be solved by some gain tweaking.
Looks like the IFO is back to a good state.
1957   Thu Aug 27 14:00:33 2009 ranaUpdatePSLRC thermal servo impulse response

I stepped the TIDALSET and looked at what happened. Loop was closed with the very low gain.

The RED guy tells us the step/impulse response of the RC can to a step in the heater voltage.

The GREY SLOWDC tells us how much the actual glass spacer of the reference cavity lags the outside can temperature.

Since MINCOMEAS is our error signal, I have upped his SCAN period from 0.5 to 0.1 seconds in the database and reduced its SMOO from 0.9 to 0.0. I've also copied over the Fricke SLOW code and started making a perl PID loop for the reference cavity.

Attachment 1: Untitled.png
1959   Fri Aug 28 12:56:17 2009 YoichiUpdateLockingRF CARM hand off problem
Last night, the lock script proceeded to the RF CARM hand-off about half of the time.
However, the hand off was still unsuccessful.

It failed instantly when you turn on the REFL1 input of the CM board, even
when the REFL1 input gain was very low, like -28dB.

I went to the LSC rack and checked the cabling.
The output from the PD11_I (REFL_2) demodulation board is split
into two paths. One goes directly to the ADC and the other one goes
to an SR560. This SR560 is used just as an inverter. Then
the signal goes to the REFL1 input of the CM board.

I found that the SR560 was set to the A-B mode, but B input was open.
This made the signal very noisy. So I changed it to A only mode.
There was also a 1/4 attenuator between the PD11_I output and the SR560.
I took it out and reduced the gain of SR560 from 10 to 2.
These changes allowed me to increase the REFL1 gain to -22dB or so.
But it is still not enough.

I wanted to check the CM open loop TF before the hand-off, but I could
not do that because the lock was lost instantly as soon as I enabled the
test input B of the CM board.
Something is wrong with the board ?

Using the PD11_I signal going into the ADC, I measured the transfer functions
from the CM excitation (digital one) to the REFL_DC (DC CARM signal) and PD11_I.
The TF shapes matched. So the PD11_I signal itself should be fine.

We should try:
* See if flipping the sign of PD11_I signal going to REFL1 input solve the problem.
* Try to measure the CM analog TF again.
* If the noise from the servo analyzer is a problem, try to increase the input gains
of the CM board and reduce the output gain accordingly, so that the signal flowing
inside the CM board is larger.
1960   Fri Aug 28 13:49:07 2009 robUpdateLockingRF CARM hand off problem

 Quote: Last night, the lock script proceeded to the RF CARM hand-off about half of the time. However, the hand off was still unsuccessful. It failed instantly when you turn on the REFL1 input of the CM board, even when the REFL1 input gain was very low, like -28dB. I went to the LSC rack and checked the cabling. The output from the PD11_I (REFL_2) demodulation board is split into two paths. One goes directly to the ADC and the other one goes to an SR560. This SR560 is used just as an inverter. Then the signal goes to the REFL1 input of the CM board. I found that the SR560 was set to the A-B mode, but B input was open. This made the signal very noisy. So I changed it to A only mode. There was also a 1/4 attenuator between the PD11_I output and the SR560. I took it out and reduced the gain of SR560 from 10 to 2. These changes allowed me to increase the REFL1 gain to -22dB or so. But it is still not enough. I wanted to check the CM open loop TF before the hand-off, but I could not do that because the lock was lost instantly as soon as I enabled the test input B of the CM board. Something is wrong with the board ? Using the PD11_I signal going into the ADC, I measured the transfer functions from the CM excitation (digital one) to the REFL_DC (DC CARM signal) and PD11_I. The TF shapes matched. So the PD11_I signal itself should be fine. We should try: * See if flipping the sign of PD11_I signal going to REFL1 input solve the problem. * Try to measure the CM analog TF again. * If the noise from the servo analyzer is a problem, try to increase the input gains of the CM board and reduce the output gain accordingly, so that the signal flowing inside the CM board is larger.

I'd bet it's in a really twitchy state by the time the script gets to the RF CARM handoff, as the script is not really validated up to that point. It's just the old script with a few haphazard mods, so it needs to be adjusted to accomodate the 15% power drop we've experienced since the last time it was locked.

The CM servo gain needs to be tweaked earlier in the script--you should be able to measure the AO path TF with the arm powers at 30 or so. I was able to do this with the current SR785 setup earlier this week without any trouble.

The 1/4 attenuator is there to prevent saturations on the input to the SR560 when there's still a CARM offset.

Not sure if flipping the sign of PD11 is right, but it's possible we compensated the digital gains and forgot about it. This signal is used for SRCL in the initial acquisition, so we'd have noticed a sign flip.
1962   Tue Sep 1 11:23:36 2009 steveUpdateGeneralelectrical ground

I was told yesterday, that on Friday the construction people accidentally ripped out one of the 40m soil ground.....AND HOW MANY MORE ARE THERE? nobody knows.

It was ~8 ft long and 0.5" diameter buried in the ground. There is no drawing found to identify this exact building ground. They promised to replace this on Wednesday with a 10 ft long and 0.75" diameter.

The  the wall will be resealed where the conduit enters  the  north west corner of the IFO room 104

There should be no concern about safety because the 40m building main ground is connected to the CES Mezzanine step-down transformer.

Attachment 1: ground.JPG
1964   Thu Sep 3 10:19:35 2009 steve, albertoUpdatePEMparticle counts and burning hillsides

The San Gabriel mountain has been on fire for  6 days. 144,000 acres of beautiful hillsides burned down and it's still burning.  Where the fires are.

The 40m lab particle counts are more effected by next door building-gardening activity than the fire itself.

This 100 days plot shows that.

Attachment 1: fire6d.jpg
Attachment 2: 40mgarden.JPG
Attachment 3: 40mgarden2.JPG
Attachment 4: RBLOG-FIRE-SKY.JPG
1965   Thu Sep 3 11:20:26 2009 steveUpdateGeneralelectrical ground in place

 Quote: I was told yesterday, that on Friday the construction people accidentally ripped out one of the 40m soil ground.....AND HOW MANY MORE ARE THERE? nobody knows. It was ~8 ft long and 0.5" diameter buried in the ground. There is no drawing found to identify this exact building ground. They promised to replace this on Wednesday with a 10 ft long and 0.75" diameter. The  the wall will be resealed where the conduit enters  the  north west corner of the IFO room 104   There should be no concern about safety because the 40m building main ground is connected to the CES Mezzanine step-down transformer.

Atm1 is showing ground bus under N-breaker panel in 40m IFO room north-west corner.

The second ground bus is visible farther down south under M-breaker panel.

Atm2 is the new ground that will be connected to ground bus-N

Attachment 1: Gs-n.JPG
Attachment 2: newground.JPG
1968   Mon Sep 7 20:05:18 2009 ranaUpdatePSLRCTEMP v. RMTEMP

Since ~Aug. 27, the reference cavity has been running with no thermal control. This is not really a problem at the 40m; a 1 deg change of the glass cavity

will produce a 5 x 10-7 strain in the arm cavity. That's around 20 microns of length change.

This open loop time gave us the opportunity to see how good our cavity's vacuum can insulation is.

The first plot below shows the RCTEMP sensors and the RMTEMP sensor. RMTEMP is screwed down to the table close to the can and RCTEMP is on the can, underneath the insulation. I have added a 15 deg offset to RMTEMP so that it would line up with RCTEMP and allow us to see, by eye, what's happening.

There's not enough data here to get a good TF estimate, but if we treat the room temperature as a single frequency (1 / 24 hours) sine wave source, then we can measure the delay and treat it as a phase shift. There's a ~3 hour delay between the RMTEMP and RCTEMP. If the foam acts like a single pole low pass filter, then the phase delay of (3/24)*360 = 45 deg implies a pole at a ~3 hour period. I am not so sure that this is a good foam model, however.

The colorful plot is a scatter plot of RCTEMP v. RMTEMP. The color denotes the time axis - it starts out blue and then becomes red after ten days.

1969   Mon Sep 7 23:18:01 2009 AlbertoUpdateLockingSome locking attempts

Tried to lock the interferometer but arm power didn't get over 65.

Tonight, after the weekend, I resumed the work on locking.

When I started the Mode Cleaner was unlocked because the MZ was also unlocked.

I aligned the MZ and the transmitted power reached about 2.5

Initially the interferometer lost lock at arm power of about 3-4. It looked like the alignment wasn't good enough. So I ran the alignment scripts a few times, first the scripts for the single parts and in the end the one for the full IFO.

Then I also locked again the MZ and this time the transmitted power got to about 4.

In the following locking attempts the the arm power reached 65 but then the lock got lost during the handing of CARM to C1:LSC-PD11_I

I'll keep working on that tomorrow night.

1970   Mon Sep 7 23:35:03 2009 ranaUpdatePSLRC thermal servo: PID script modified, database + screen added

I have added the records for the RC thermal PID servo into the psl/slowpid.db file which also holds the records for the SLOW servo that uses the NPRO-SLOW to minimize the NPRO-FAST. This new database will take effect upon the next PSL boot.

The perl script which runs the servo is scripts/PSL/FSS/RCthermalPID.pl. Right now it is using hard-coded PID parameters - I will modify it to use the on-screen values after we reboot c1psl.

The new screen C1PSL_FSS_RCPID.adl, the script, and the .db have been added to the SVN.

I have got some preliminary PID parameters which seem to be pretty good: The RCTEMP recovers in ~10 minutes from a 1 deg temperature step and the closed loop system is underdamped with a Q of ~1-2.

I'm leaving it running on op340m for now - if it goes crazy feel free to do a 'pkill RCthermalPID.pl'.

Attachment 1: Untitled.png
1972   Tue Sep 8 12:26:16 2009 AlbertoUpdatePSLConnection of the RC heater's power supply replaced

I have replaced the temporary clamps that were connecting the RC heater to its power supply with a new permanent connection.

In the IY1 rack, I connected the control signal of the RC PID temperature servo - C1:PSL-FSS_TIDALSET - to the input of the RC heater's power supply.

The signal comes from a DAC in the same rack, through a pair of wires connected to the J9-4116*3-P3 cross-connector (FLKM). I joined the pair to the wires of the BNC cable coming from the power supply, by twisting and screwing them into two available clamps of the breakout FKLM in the IY1 rack - the same connected to the ribbon cable from RC Tmeperature box.

Instead of opening the BNC cable coming from the power supply, I thought it was a cleaner and more robust solution to use a BNC-to-crocodile clamp from which I had cut the clamps off.

During the transition process, I connected the power supply BNC input to a a voltage source that I set at the same voltage of the control signal before I disconnected it (~1.145V).

I monitored the temperature signals and it looked like the RC Temperature wasn't significantly affected by the operation.

1975   Tue Sep 8 17:57:30 2009 JenneUpdatePEMAll the Acc/Seis working again

All of the accelerometers and seismometers are plugged in and functional again.  The cables to the back of the accelerometer preamp board (sitting under the BS oplev table) had been unplugged, which was unexpected.  I finally figured out that that's what the problem was with half of the accelerometers, plugged them back in, and now all of the sensors are up and running.

TheSEIS_GUR seismometer is under MC1, and all the others (the other Guralp, the Ranger which is oriented vertically, and all 6 accelerometers) are under MC2.

1976   Tue Sep 8 19:30:33 2009 ranaUpdatePSLc1psl rebooted for new RCPID database settings

The RC thermal PID is now controllable from its own MEDM screen which is reachable from the FSS screen. The slowpid.db and psl.db have been modified to add these records and all seems to be working fine.

Also, I've attached the c1psl startup output that we got on the terminal. This is just for posterity.

I'm also done tuning the PID for now. Using Kp = -1.0, Ki = -0.01, and Kd = 0, the can servo now has a time constant of ~10 minutes and good damping as can be seen in the StripTool snap below. These values are also now in the saverestore.req so hopefully its fully commissioned.

I bet that its much better now than the MINCO at holding against the 24 hour cycle and can nicely handle impulses (like when Steve scans the table). Lets revisit this in a week to see if it requires more tuning.

Attachment 1: c1psl-term-dump.txt.gz
Attachment 2: C1PSL_FSS_RCPID.png
Attachment 3: Picture_1.png
1981   Thu Sep 10 15:55:44 2009 JenneUpdateComputersc1ass rebooted

c1ass had not been rebooted since before the filesystem change, so when I was sshed into c1ass I got an error saying that the NFS was stale.  Sanjit and I went out into the cleanroom and powercycled the computer.  It came back just fine.  We followed the instructions on the wiki, restarting the front end code, the tpman, and did a burt restore of c1assepics.

1982   Thu Sep 10 17:47:25 2009 JenneUpdateComputerschanges to the startass scripts

[Rana, Jenne]

While I was mostly able to restart the c1ass computer earlier today, the filter banks were acting totally weird.  They were showing input excitations when we weren't putting any, and they were showing that the outputs were all zero, even though the inputs were non-zero and the input and the output were both enabled. The solution to this ended up being to use the 2nd to last assfe.rtl backup file.  Rana made a symbolic link from assfe.rtl to the 2nd to last backup, so that the startup.cmd script does not need to be changed whenever we alter the front end code.

The startup_ass script, in /caltech/target/gds/ which, among other things, starts the awgtpman was changed to match the instructions on the wiki Computer Restart page.  We now start up the /opt/gds/awgtpman .  This may or may not be a good idea though, since we are currently not able to get channels on DTT and Dataviewer for the C1:ASS-TOP_PEM channels.  When we try to run the awgtpman that the script used to try to start ( /caltech/target/gds/bin/ ) we get a "Floating Exception". We should figure this out though, because the /opt/gds/awgtpman does not let us choose 2kHz as an option, which is the rate that the ASS_TOP stuff seems to run at.

The last fix made was to the screen snapshot buttons on the C1:ASS_TOP screen.  When the screen was made, the buttons were copied from one of the other ASS screens, so the snapshots saved on the ASS_TOP screen were of the ASS_PIT screen.  Not so helpful.  Now the update snapshot button will actually update the ASS_TOP snapshot, and we can view past ASS_TOP shots.

1983   Thu Sep 10 18:25:15 2009 ranaUpdatePSLc1psl rebooted for new RCPID database settings

I added a new database record (C1:PSL-FSS_RCPID_SETPOINT) to allow for changing of the RC setpoint while the loop is on. This will enable us to step the can's temperature and see the result in the NRPO's SLOWDC.

1984   Fri Sep 11 17:07:45 2009 JenneUpdateAdaptive FilteringMinor changes to ASS_TOP_PEM screen.

There was some uncertainty as to which channels were being input into the Adaptive Filtering screen, so I checked it out to confirm.  As expected, the rows on the ASS_TOP_PEM screen directly correspond to the BNC inputs on the PEM_ADCU board in the 1Y6 (I think it's 6...) rack.  So C1:ASS-TOP_PEM_1_INMON corresponds to the first BNC (#1) on the ADCU, etc.

After checking this out, I put text tags next to all the inputs on the ASS_TOP_PEM screen for all of the seismometers (which had not been there previously).  Now it's nice and easy to select which witness channels you want to use for the adaptation.

1985   Fri Sep 11 17:11:15 2009 SanjitUpdateASSOAF: progress made

[Jenne & Sanjit]

Good news: We could successfully send filtered output to MC1 @ SUS.

We used 7 channels (different combinations of 3 seismometer and six accelerometer)

We tried some values of \mu (0.001-0.005) & gain on SUS_MC1_POSITION:MCL and C1ASS_TOP_SUS_MC1 (0.1-1).

C1:ASS-TOP_SUS_MC1_INMON is huge (soon goes up to few times 10000), so ~0.1 gains at two places bring it down to a reasonable value.

Bad news: no difference between reference and filtered IOO-MC_L power spectra so far.

Plan of action: figure out the right values of the parameters (\mu, \tau, different gains, and may be some delays), to make some improvement to the spectra.

** Rana: there's no reason to adjust any of the MCL gains. We are not supposed to be a part of the adaptive algorithm.

1986   Sat Sep 12 15:40:15 2009 ranaUpdatePSLRC response v. can temperature

I stepped the RC can temperature to see the response in the laser frequency. This gives a true measure of the thermal time constant of the RC. Its ~4 hours.

Since the RCPID screen now has a setpoint field, I can remotely type in 1 deg steps. The NPRO SLOW actuator locks the NPRO to the RC at long time scales and so we can use C1:PSL-FSS_SLOWDC to measure the RC length. By knowing what the step response time constant is, we can estimate the transfer function from can temperature to frequency noise and thereby make a better heater circuit.

Does the observed temperature shift make any sense? Well, John Miller and I measured the SLOW calibration to be 1054 +/- 30 MHz / V.

We know that the thermal expansion coefficient of fused silica, alpha = 5.5 x 10-7 (dL/L)/deg. So the frequency shift ought to be alpha * c / lambda = 155 MHz / deg.

Instead we see something like 110 MHz / deg. We have to take more data to see if the frequency shift will actually asymptote to the right value or not. If it doesn't, one possibility is that we are seeing the effect of temperature on the reflection phase of the mirror coatings through the dn/dT and the thermal expansion of the dielectric layers. I don't know what these parameters are for the Ta2O5 layers.

A more useful measure of the frequency noise can be gotten by just looking at the derivative in the first 30 minutes of the step, since that short time scale is much more relevant for us. Its 0.04 V / hour / (2 deg) =>  860 (Hz/s)/deg.

In the frequency domain this comes out to be dnu/dT = 860 Hz/deg @ 0.16 Hz or dnu/dT = 137 *(1/f) Hz / deg.

Our goal for the reference cavity frequency noise is 0.01 * (1/f) Hz/rHz. So the temperature noise of the can needs to be < 0.1 mdeg / rHz.

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Attachment 2: Untitled.pdf
1987   Tue Sep 15 15:46:05 2009 steveUpdatePEMPEM and VAC

FSS_RMTEMP is moving up and  daily fluctuations  are  less . 120 and 16 days plots are below.

Attachment 1: 120dpem.jpg
Attachment 2: 16dpem.jpg
1988   Wed Sep 16 11:58:11 2009 JenneUpdateAdaptive FilteringNew Filters for Adaptive Filtering

When Sanjit and I were looking at the adaptive filtering system on Monday and Friday, we noticed that turning on the Accelerometers (which had been used in the past) seemed to do good things, but that turning on the seismometers (which I just put into the system last week) made the OAF output integrate up.  Rana pointed out that this is an indication of a missing high pass filter.  And indeed, when I put the seismometers in, I neglected to copy the high pass filter at low frequencies, and the low pass at 64Hz from the accelerometer path to the seismometer path.  The accelerometers had a HP at 1Hz, which is okay since they don't really do useful things down to the mHz level.  I gave all of the seismometers HP at 1mHz.  These are now in the filter banks in the ASS_TOP_PEM screen.  The accelerometers are on channels 15, 16, 17, 18, 19, 20 and the seismometers are on channels 2, 3, 4, 10, 11, 12, 24.

I now need to modify the upass script to turn these filters on before doing adaptive filtering.

1989   Thu Sep 17 14:17:04 2009 robUpdateComputersawgtpman on c1omc failing to start

[root@c1omc controls]# /opt/gds/awgtpman -2 &
[1] 16618
[root@c1omc controls]# mmapped address is 0x55577000
32 kHz system
Spawn testpoint manager
no test point service registered
Test point manager startup failed; -1

[1]+  Exit 1                  /opt/gds/awgtpman -2

1990   Thu Sep 17 15:05:47 2009 robUpdateComputersawgtpman on c1omc failing to start

 Quote: [root@c1omc controls]# /opt/gds/awgtpman -2 & [1] 16618 [root@c1omc controls]# mmapped address is 0x55577000 32 kHz system Spawn testpoint manager no test point service registered Test point manager startup failed; -1 [1]+  Exit 1                  /opt/gds/awgtpman -2

This turned out to be fallout from the /cvs/cds transition.  Remounting and restarting fixed it.

1995   Wed Sep 23 19:36:41 2009 ranaUpdatePSLRC temperature performance

This first plot shows the RC temperature channels' performance from 40 days ago, before we disabled the MINCO PID controller. Although RCTEMP is supposed to be the out of loop sensor, what we really care about is the cavity length and so I've plotted the SLOW. To get the SLOW on the same scale, I've multiplied the channel by 10 and then adjusted the offset to get it on the same scale.

The second plot shows a period after that where there is no temperature control of the can at all. Same gain scaling has been applied to SLOW as above, so that instead of the usual 1 GHz/V this plot shows it in 0.1 GHz/V.

The third plot shows it after the new PID was setup.

Summary: Even though the PID loop has more gain, the true limit to the daily fluctuations in the cavity temperature and the laser frequency are due to the in-loop sensors measuring the wrong thing. i.e. the out-of-loop temperature is too different from the in-loop sensor. This can possibly be cured with better foam and better placement of the temperature sensors. Its possible that we're now just limited by the temperature gradients on the can.

Attachment 1: Untitled.png
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1997   Thu Sep 24 15:45:27 2009 robUpdateIOOMC OLG

I measured the mode cleaner open loop gain with the HP3563A

The UGF is 64kHz, phase margin is 28 deg.

2000   Thu Sep 24 21:04:15 2009 JenneUpdateMOPAIncreasing the power from the MOPA

[Jenne, Rana, Koji]

Since the MOPA has been having a bad few weeks (and got even more significantly worse in the last day or so), we opened up the MOPA box to increase the power.  This involved some adjusting of the NPRO, and some adjusting of the alignment between the NPRO and the Amplifier.  Afterward, the power out of the MOPA box was increased.  Hooray!

Steps taken:

0.  Before we touched anything, the AMPMON was 2.26, PMC_Trans was 2.23, PSL-126MOPA_126MON was 152 (and when the photodiode was blocked, it's dark reading was 23).

1.  We took off the side panel of the MOPA box nearest the NPRO, to gain access to the potentiometers that control the NPRO settings.  We selectively changed some of the pots while watching PSL-126MOPA_126MON on Striptool.

2.  We adjusted the pot labeled "DTEMP" first. (You have to use a dental mirror to see the labels on the PCB, but they're there). We went 3.25 turns clockwise, and got the 126MON to 158.

3. To give us some elbow room, we changed the PSL-126MOPA_126CURADJ from +10.000 to 0.000 so that we have some space to move around on the slider.  This changed 126MON to 142. The 126MOPA_CURMON was at 2.308.

4.  We tried adjusting the "USR_CUR" pot, which is labeled "POWER" on the back panel of the NPRO (you reach this pot through a hole in the back of the NPRO, not through the side which we took off, like all the other pots today).  This pot did nothing at all, so we left it in its original position.  This may have been disabled since we use the slider.

5.  We adjusted the CUR_SET pot, and got the 126MON up to 185.  This changed the 126MOPA_CURMON to 2. 772 and the AMPMON to 2.45

We decided that that was enough fiddling with the NPRO, and moved on to adjusting the alignment into the Amplifier.

6.  We teed off of the AMPMON photodiode so that we could see the DC values on a DMM.  When we used a T to connect both the DMM and the regular DAQ cable, the DMM read a value a factor of 2 smaller than when the DMM was connected directly to the PD.  This shouldn't happen.....it's something on the to-fix-someday list.

7.  Rana adjusted the 2 steering mirrors immediately in front of the amplifier, inside the MOPA box.  This changed the DMM reading from its original 0.204 to 0.210, and the AMPMON reading from 2.45 to 2.55. While this did help increase the power, the mirrors weren't really moved very much.

8.  We then noticed that the beam wasn't really well aligned onto the AMPMON PD.  When Rana leaned on the MOPA box, the PD's reading changed.  So we moved the PD a little bit to maximize its readings.  After this, the AMPMON read 2.68, and the DMM read 0.220.

9.  Then Rana adjusted the 2 waveplates in the path from the NPRO to the Amplifier.  The first waveplate in the path didn't really change anything.  Adjusting the 2nd waveplate gave us an AMPMON of 2.72, and a DMM reading of 0.222.

10.  We closed up the MOPA box, and locked the PMC.  Unfortunately, the PMC_Trans was only 1.78, down from the 2.26 when we began our activities.  Not so great, considering that in the end, the MOPA power went up from 2.26 to 2.72.

11.  Koji and I adjusted the steering mirrors in front of the PMC, but we could not get a transmission higher than 1.78.

12.  We came back to the control room, and changed the 126MOPA_126CURADJ slider to -2.263 which gives a 126MOPA_CURMON to 2.503.  This increased PMC_TRANS up to 2.1.

13.  Koji did a bit more steering mirror adjustment, but didn't get any more improvement.

14.  Koji then did a scan of the FSS SLOW actuator, and found a better temperature place (~ -5.0)for the laser to sit in.  This place (presumably with less mode hopping) lets the PMC_TRANS get up to 2.3, almost 2.4.  We leave things at this place, with the 126MOPA_126CURADJ slider at -2.263.

Now that the MOPA is putting out more power, we can adjust the waveplate before the PBS to determine how much power we dump, so that we have ~constant power all the time.

Also, the PMCR view on the Quad TVs in the Control Room has been changed so it actually is PMCR, not PMCT like it has been for a long time.

2001   Fri Sep 25 16:10:17 2009 JenneUpdateAdaptive FilteringSome progress on OAF, but more still to be done

[Jenne, Sanjit]

It seems now that we are able to get the OAF system to do a pretty good job of approximating the MC_L signal, but we can't get it to actually do any subtracting.  I think that we're not correctly setting the phase delay between the witness and the MC_L channels or something (I'm not sure though why we get a good filter match if the delay is set incorrectly, but we do get a good filter match for very different delay settings: 1, 5, 100, 1000 all seem to do equally well at adjusting the filter to match MC_L).

The Matt Evans document in elog 395 suggests measuring the phase at the Nyquist frequency, and calculating the appropriate delay from that.  The sticking point with this is that we can't get test points for any channel which starts with C1:ASS.  I've emailed Alex to see what he can do about this.  Elog 1982 has a few words about how we're perhaps using a different awgtpman on the ass machine than we used to, which may be part of the problem.

The golden plan, which in my head will work perfectly, is as follows: Alex will fix the testpoint problem, then Sanjit and I will be able to measure the phase between our OAF signal and the incoming MC_L signal, we will be able to match them as prescribed in the Matt Evans document, and then suddenly the Adaptive Filtering system will do some actual subtracting!

The plot below shows the Reference MC_L without any OAF system (black), the output of the OAF (green), and the 'reduced' MC_L (red).  As you can see, the green trace is doing a pretty good job of matching the black one, but the red trace isn't getting reduced at all.

Attachment 1: OAF_Running_25Sept2009.jpg
2002   Fri Sep 25 16:45:29 2009 JenneUpdateMOPATotal MOPA power is constant, but the NPRO's power has decreased after last night's activities?

[Koji, Jenne]

Steve pointed this out to me today, and Koji and I just took a look at it together:  The total power coming out of the MOPA box is constant, about 2.7W.  However, the NPRO power (as measured by 126MOPA_126MON) has decreased from where we left it last night.  It's an exponential decay, and Koji and I aren't sure what is causing it.  This may be some misalignment on the PD which actually measures 126MON or something though, because 126MOPA_LMON, which measures the NPRO power inside the NPRO box (that's how it looks on the MEDM screen at least...) has stayed constant.  I'm hesitant to be sure that it's a misalignment issue since the decay is gradual, rather than a jump.

Koji and I are going to keep an eye on the 126MON value.  Perhaps on Monday we'll take a look at maybe aligning the beam onto this PD, and look at the impedance of both this PD, and the AMPMON PD to see why the reading on the DMM changed last night when we had the DAQ cable T-ed in, and not T-ed in.

Attachment 1: AMPMONconstant_126MONdown.jpg
2003   Fri Sep 25 17:51:51 2009 KojiUpdateMOPASolved (Re: Total MOPA power is constant, but the NPRO's power has decreased after last night's activities?)

Jenne, Koji

The cause of the decrease was found and the problem was solved. We found this entry, which says

Yoich> We opened the MOPA box and installed a mirror to direct a picked off NPRO beam to the outside of the box through an unused hole.
Yoich> We set up a lens and a PD outside of the MOPA box to receive this beam. The output from the PD is connected to the 126MON cable.

We went to the PSL table and found the dc power cable for 126MOPA_AMPMON was clipping the 126MON beam.
We also made a cable stay with a pole and a cable tie.

After the work, 126MON went up to 161 which was the value we saw last night.

We also found that the cause of the AMPMON signal change by the DAQ connection, mentioned in this entry:

Jenne> 6.  We teed off of the AMPMON photodiode so that we could see the DC values on a DMM.
Jenne> When we used a T to connect both the DMM and the regular DAQ cable, the DMM read
Jenne> a value a factor of 2 smaller than when the DMM was connected directly to the PD.

We found a 30dB attenuator is connected after the PD. It explains missing factor of 2.

 Quote: [Koji, Jenne] Steve pointed this out to me today, and Koji and I just took a look at it together:  The total power coming out of the MOPA box is constant, about 2.7W.  However, the NPRO power (as measured by 126MOPA_126MON) has decreased from where we left it last night.  It's an exponential decay, and Koji and I aren't sure what is causing it.  This may be some misalignment on the PD which actually measures 126MON or something though, because 126MOPA_LMON, which measures the NPRO power inside the NPRO box (that's how it looks on the MEDM screen at least...) has stayed constant.  I'm hesitant to be sure that it's a misalignment issue since the decay is gradual, rather than a jump.  Koji and I are going to keep an eye on the 126MON value.  Perhaps on Monday we'll take a look at maybe aligning the beam onto this PD, and look at the impedance of both this PD, and the AMPMON PD to see why the reading on the DMM changed last night when we had the DAQ cable T-ed in, and not T-ed in.

2004   Fri Sep 25 19:55:59 2009 JenneUpdateAdaptive FilteringSubtraction of the microseism using Adaptive Filtering!

[Rana, Jenne]

The OAF system did something useful today!  Attached is a plot.  Black is the reference (13 averages) with the OAF off.  Blue is the output of the OAF, and red is the reduced MC_L signal (13 averages).  If you turn tau and mu both to 0, it "pauses" the filter, but keeps the feedforward system working, so that you can take a long average to get a better idea of how well things are working. If you ramp down the output of the CORR filter bank, that lets you take a long average with the OAF "off", but doesn't mess up your nicely adapted filter.  The cyan and gold traces in the upper plot are 2 of the Guralp channels, so you can see the real seismic motion.

In the lower plot, you can see that the cyan and light green seismic channels have good coherence with IOO-MC_L (the names don't really mean anything right now...these 2 seismometer channels are the 2 Guralps' channels, one per end of the MC, which are aligned with the MC.)  The dark blue trace is the coherence between IOO-MC_L and the output of the OAF.

500 taps, delay=5, 2 Guralp channels (the ones aligned with the MC), tau~0.00001 (probably), and mu~0.01 or 0.005

Attachment 1: OAF_running_WORKING_25Sept2009.png
2006   Sat Sep 26 13:55:20 2009 JenneUpdateMZMZ was locked in a bad place

I found the MZ locked in a bad place earlier today.  It was locked in a similarly bad spot yesterday after we fixed the cable situation for 126MOPA_126MON, with reflection of ~0.8, rather than the nominal 0.305.  It's good now though.

2007   Sun Sep 27 12:52:56 2009 ranaUpdateMOPAIncreasing the power from the MOPA

This is a trend of the last 20 days. After our work with the NPRO, we have recovered only 5% in PMC trans power, although there's an apparent 15% increase in AMPMON.

The AMPMON increase is partly fake; the AMPMON PD has too much of an ND filter in front of it and it has a strong angle dependence. In the future, we should not use this filter in a permanent setup. This is not a humidity dependence.

The recovery of the refcav power mainly came from tweaking the two steering mirrors just before and just after the 21.5 MHz PC. I used those knobs because that is the part of the refcav path closest to the initial disturbance (NPRO).

BTW, the cost of a 1W Innolight NPRO is $35k and a 2W Innolight NPRO is$53k. Since Jenne is on fellowship this year, we can afford the 2W laser, but she has to be given priority in naming the laser.

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2008   Sun Sep 27 14:45:45 2009 KojiUpdatePSLSLOWscan result

I ran (script dir)/PSL/FSS/SLOWscan on op440m from 11:30 to 12:30 on 27th. Although Rana and later I myself set "timed bombs" for the scan, they did not work as they have probably been ran on Linux. After the scan I relocked PMC, FSS, and MZ . MC locked automatically.

Observation:

1. To keep away from the mode hop, FSS_SLOWDC is to be at around 0. The values -5 ~ -6 is the place for the power, which is my preference for now. BTW, the mode hop only appears to the PSL output (=AMPMON) is this normal?

2. The PSL output looks dependent on the NPRO wavelength. The NPRO output and the PSL output tends to be high when the FSS_SLOWDC is low (= LTMP: Laser Crystal Temp is low). Also there is a step at the LTMP where we think the mode hop is present. This may cause the daily PSL output variation which induced by the daily change of the reference cavity length.

My naive speculation is that the NPRO wavelength is too long (= hot side) for the MOPA absorption as the MOPA heads are cooled to 19deg.

3. Scanning of -10 to +10 changes the LTMP from 42-49deg. This is almost 1/10 of the NPRO capability. The manual told us that we should be able to scan the crystal temperature +/-16deg (about 30deg to 60deg).

What I like to try:
a) Change the NPRO temp to more cold side.
b) Change the MOPA head temp to a bit hot side.
c) Tweak the MOPA current (is it difficult?)

Attachment 1: SLOWscan_090927.png
Attachment 2: Pages_from_miser_126_manual.png
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