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.

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.

 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

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.

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.

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'.

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.

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.

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.

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. 

[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.

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.

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.

[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.

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.

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

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.

[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.

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.

I measured the mode cleaner open loop gain with the HP3563A. 

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

[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.

[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.

[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. 

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.

[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

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. 

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.

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?)

 I think that the AMPMON ND problem was just that the responsivity changes with angle. So when I aligned it a little we got some few% improvement in the signal which is not a real power increase.

I don't think we can adjust any of the MOPA parameters because the controller is broken, but we can try the NPRO crystal temperature.

While trying to make the OAF work, I found that the XYCOM switches for MC1/3 have been set in the bad way for awhile. This means that the hardware filters were bypassed and that MC1 & MC3 were moving around too much at high frequency and possibly causing trouble with the locking. I have put them back into the default position.

On Friday, Jenne and I were playing around with turning the dewhitening off/on to see if it efffected the OAF stability. At the time, I didn't pay too much attention to what the state was. Looks like it was in the wrong state (hardware bypassed) when we found it. For the OAF work, we generally want it in that bypassed state, but its bad because it makes noise in the interferometer. The bits in question are bits 16-23 on the XYCOM screen.

I have updated the snapshot and set the screen in the appropriate settings. I used a swept sine measurement to verify the filter state. In the attached plot, green corresponds to XYCOM green and red corresponds to red.

I used Kakeru's instructions in elog 1221 to add the C1OAF screen (still called C1ASS_TOP) to the medm screenshots webpage.  The tricky part of this is figuring out that the file that needs editing is in fact in /cvs/cds/projects/statScreen, not /cvs/cds/caltech/statScreen, as claimed in the entry. 

The PSL/IOO combo has not been behaving responsibly recently. 

The first attachment is a 15 day trend of the MZ REFL, ISS INMON, and MC REFL power.  These show two separate problems--recurring MZ flakiness, which may actually be a loose cable somewhere which makes the servo disengage.  Such disengagement is not as obvious with the MZ as it is with other systems, because the MZ is relatively stable on its own.  The second problem is more recent, just starting in the last few days.  The MC is drifting off the fringe, either in alignment, length, or both.  This is unacceptable.

The second attachment is a two-day trend of the MC REFL power.  Last night I carefully put the beam on the center of the MC-WFS quads.  This appears to have lessened the problem, but it has not eliminated it. 

It's probably worth trying to re-measure the MCWFS system to make sure the control matrix is not degenerate. 

Rana, Jenne, Koji

Last night we checked MZ. The apparent thing we found was the gain slider does not work.
The slider actually changes the voltage at the cross connection of 1Y2 (31 pin4?), the gain does not change.
The error spectrum didn't change at all even when the slider was moved.

Rana poked the flat cable at the bottom of 1Y2, we had no imporvement.

We coudn't find the VME extender board, so we just replaced AD602 (=VGA) and LT1125 (=Buffer for the ctrl voltage).
Even after the replacement, the gain slider is not working yet.

Today, I will put a lead or probe to the board to see whether the slider changes the voltage on the board or not.

Somehow the gain is sitting at a intermediate place that is not to low not to high. So I still don't know the gain slider
is the cause of the MZ instability or not.

12:45 I started the work on MZ. Thus the MZ was unlocked.

Found the bad connection on the FLKM 64pin cross connection board. We need a replacement.

I went to Wilson and got the replacement, two VME extender boards, three 7815, and three 7915. Thanks, Ben!

The MZ work completed. I replaced the bad cross connection terminal. The gain slider is working now.

I looked at the error spectrum on an FFT analyzer. I could see the lock was more tight.

Then I proceeded to the MZ epics panel.

1) C1:PSL-MZ_MZTRANSPD has no meaning (not connected). So I put  C1:PSL-ISS_INMONPD as the MZ trans monitor.

2) The EPICS setting for the MZ gain slider was totaly wrong.
    Today I learned from the circuit, the full scale of the gain slider C1:PSL-MZ_GAIN gave us +/-10V at the DAC.
    This yield +/-1V to V_ctrl of the AD602 after the internal 1/10 attenuation stage.
    This +/-1V didn't correspond to -10dB~+30dB, but does -22dB~+42dB and is beyond the spec of the chip.

    The gain of AD602 is calculated by

G [dB] = 32 V_crtl + 10,  for -0.625 [V]< V_ctrl < +0.625 [V].

    In order to fix this I used the following commands which overrode the EPICS parameters.
    The tip of EGUF/EGUL is to know how much the gain (virtually) goes for the full scale of the DAC output. 

ezcawrite C1:PSL-MZ_GAIN.EGUF 42
ezcawrite C1:PSL-MZ_GAIN.EGUL -22
ezcawrite C1:PSL-MZ_GAIN.DRVH 30
ezcawrite C1:PSL-MZ_GAIN.DRVL -10
ezcawrite C1:PSL-MZ_GAIN.HOPR 30
ezcawrite C1:PSL-MZ_GAIN.LOPR -10

   and for the permanent change I modified the db file /cvs/cds/caltech/target/c1iool0/c1iooMZservo.db
   This will be active when cliool0 is rebooted.

# This yields the output limited to -6.25V ~ +6.25V, which corresponds to -10dB ~ +30dB
# modified by Koji Arai (29-Sept-2009)
grecord(ao,"C1:PSL-MZ_GAIN")
{
        field(DESC,"GAIN- overall pre-modecleaner servo loop gain")
        field(SCAN,"Passive")
        field(PINI,"YES")
        field(DISV,"1")
        field(DTYP,"VMIVME-4116")
        field(OUT,"#C3 S5 @")
        field(EGUF,"42")
        field(EGUL,"-22")
        field(PREC,"1")
        field(EGU,"dB")
        field(HOPR,"30")
        field(LOPR,"-10")
        field(DRVH,"30")
        field(DRVL,"-10")
        field(LINR,"LINEAR")
        field(OROC,"0")
        field(DOL,"0")
}

# previous code
grecord(ao,"C1:PSL-MZ_GAIN")
{
        field(DESC,"GAIN- overall pre-modecleaner servo loop gain")
        field(SCAN,"Passive")
        field(PINI,"YES")
        field(DISV,"1")
        field(DTYP,"VMIVME-4116")
        field(OUT,"#C3 S5 @")
        field(EGUF,"30")
        field(EGUL,"-10")
        field(PREC,"4")
        field(EGU,"Volts")
        field(HOPR,"30")
        field(LOPR,"-10")
        field(LINR,"LINEAR")
        field(OROC,"0")
        field(DOL,"0")
}

Since we used to run with a gain slider setting of +15 dB on the MZ, I wanted to check that the new setting of +30dB was OK. It is.

To check it I turned it up and looked for some excess noise in the ISS or in the MC. There was none. I also set the input offset slider by unlocking the PMC and zeroing the mixer monitor readback. The new slider setting is -6.5V.

I don't know why we would need more gain on the MZ loop, but we can have some if we want it by turning up the gain before the servo (optical or RF). The attached plot shows the MC_F and ISS signals with the ISS loop on and off. There was no change in either of these spectra with the MZ gain high or low.

The previous "+15" was Vctrl = 0.25 [V]. Which was +18 dB.

Probably there is the same mistake for the PMC gain slider. Possibly on the FSS slider, too???

We had a redo of elog entry 975 tonight.  The noisy OSEM was fixed by jiggling the rack end of the long cable.  Don't know exactly where--I also poked around the OSEM PD interface board.

In the attached PDF the reference trace is the noisy one.

much grief.  somehow a burt restore of c1iscepics failed to work, and so the LSC XYCOM settings were not correct.  This meant that the LSC whitening filter states were not being correctly set and reported, making it difficult to lock for at least the last week or so.

It's been a miserable week for lock acquisition, with each night worst than the last.  The nadir was around Sunday night, when I couldn't even get a PRM to lock stably, which meant that the auto-alignment scripts could not finish successfully.  It now appears that was due to some XYCOM mis-settings. 

We've also been having problems with timing for c1susvme2.  Attached is a one-hour plot of timing data for this cpu, known as SRM.  Each spike is an instance of lateness, and a potential cause of lock loss.  This has been going on for a quite a while.

Tonight we also encountered a large peak in the frequency noise around 485 Hz.  Changing the MZ lock point (the spot in the PZT range) solved this.

I'm blaming Zach on this one, for trying to upload a pic into the ATF elog (even though he claims it was small....)  Blame assigned: check.  Elog restarted: check.

[Sanjit, Jenne]

The up and down scripts accessible from the OAF (still C1:ASS-TOP) screen are now totally functional and awesome.  They are under the blue ! button.  The up script can either be for the Seismometers, or the Accelerometers at this time.  The only difference between these 2 is which burt restore file they look at:  the seismometer version puts all 7 seismometer channels in the PEM selecting matrix, while the accelerometer version puts the 6 accelerometer channels in that matrix.  Both scripts also turn on HP_1mHz filters in the ERR_EMPH filter bank and all of the witness filter banks, and the AA32 and AI32 filters in ERR_EMPH, CORR and PEM filter banks.  This makes all of the starting filters the same between the witness paths and the error path.

If you want to use a different combination of sensors, run one of the up scripts, then change the PEM matrix by hand. 

The down script disables the output to the optics, and resets the adapted filter coefficients.  DO NOT use this script if you're trying to "pause" the filter to take some nice long averages.

Good progress in IFO locking tonight, with the arm powers reaching about half the full resonant maximum. 

Still to do is check out some weirdness with the OMC DAC, fix the wireless network, and look at c1susvme2 timing.

Earthquake  of magnitude 5.0  shakes ETMY loose.

MC2 lost it's damping later.

MZ stayed unlocked. Now It was relocked.

 The EQ did not change the input beam pointing. All back to normal, except MC2 wachdogs tripped again.