Suresh killed the elogd again from India. This was the log file:

Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Referer: http://www.ligo.caltech.edu/~ajw/40m_upgrade.html
Cookie: elmode=threaded; __utma=65601905.411937803.1291369887.1291369887.1291369887.1; __utmz=65601905.1291369887.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); SITESERVER=ID=4981c5fd42ae53c9c9e0980f2072be4f
Via: 1.1 sfire5.du.ac.in:3128 (squid/2.6.STABLE6)
X-Forwarded-For: 10.11.1.120
Cache-Control: max-age=259200
Connection: keep-alive

Stop killing our elog!

c0rga apparently had a full hard drive.  There was 1 Gig log file in /var/log directory, called Xorg.0.log.old which I deleted which freed up about 20% of the hard drive.  This let me then modify the crontab file (which previously had been complaining about no room on disk to make edits).

I updated the crontab to look at the new scripts location, updated the RGA script itself to write to the new log location, and then created a soft link in the /opt directory to /cvs/cds/rtcds on c0rga.

The RGA script should now be running again once a day.

After another elog crash, I've blacklisted the domain that Suresh is using by editing the apache httpd.conf. Let's see what happens now.

Yesterday, a sequence of force and gain measurement was made to determine the imbalance in the

quadrant, magnetic-levitation prototype. This was the reason why it failed to achieve a stable levitation.

The configuration is shown schematically by the figure below:

Specifically, the following measurements have been made:

(1) DC force measurement among four pairs of magnets at fixed distance with current of the coils on and off

From this measurement,  the DC force between pair of magnets is determined and is around 1.6 N at with a

separation of 1 cm. This measurement also lets us know the gain from voltage to force near the working point.

The force between pair "2" is about 13% stronger than other pairs which are nearly identical. The force by the

coil is around 0.017 N per Volt (levitation of 5 g per 3 Volt); therefore, we need around 12 volt DC compensation

of pair "2" in order to counterbalance such an imbalance.  Given the resistence of the coil equal to 26 Om, this

requires almost 500 mA DC compensation. Koji suggested that we need a high-current buffer, instead of what

has been used now.

(2) DC force measurement among four pairs of magnets (with current of the coils off) as a function of distance

From this measurement, we can determine the stiffness of the system. In this case, the stiffness or the

effective spring constant is negative, and we need to compensate it by using a feedback control. This is

one of the most important parameters for designing the feedback control. The data is still in processing.

(3) Gain measurement of the OSEM from the displacement to voltage.

This measurement is a little bit tricky due to the difficulty to determine the displacement of the flag.

After several measurements, it gave approximately 2 V/cm.

Plan for the next few days:

From the those measurements, all the parameters for the plant and sensor that need to determine the

feedback control are known. They should be plugged into the simulink model and to see whether the

old design is appropriate or not. Concerning the experimental part, we will first try to levitate the configuration

with 2 pairs of magnets, instead of 4 pairs, as the first step, which is easier to control but still interesting.

According to c1scy.mdl, OL signals should be connected to adc_0_24 to adc_0_27 but they were connected to adc_0_16 to adc_0_19 which are assigned to QPD signals.

Actually cable connections were messed up. One ribbon cable was connected from QPD driver and ADC ports assigned for OL, and another ribbon cable was connected from the board combining the signals of oplev and QPD to ADC port assigned for QPD.

Now ETMY oplev is working well and aligned to center.

[Jenne Kiwamu Joe Osamu Steve Koji]

Yesterday (21st), we closed the BSC and the four testmass chambers.

We splitted the team into three.

- Wiping team (Jenne/Kiwamu)
- Suspension team (Osamu/Koji)
- Door closing team (Joe/Steve)

While the wiping team was working, the suspension team prepared the next suspension.
Once the mirror was wiped, the suspension team restored that suspension at the position of the markings on the table.

After the wipe of the first mirror, the wiping team got experienced and they were the fastest among the teams.
So the wiping team worked as the second suspension team when necessary.

All of us became the closing team after the last suspension has been restored.

We checked that we still have the Michelson fringes and the oplev pointings.

In total, the work was very efficient such that we only took four hours for the entire process.

We left the suspension marking on the optical tables because they are quite useful.

ELOG has crashed and I restarted it.

Actually the filtering is not effective so far as elog is not using apache but has its own web server inside.
So this just block the access to port 30889 (=SVN, Dokuwiki, etc).

Sorry folks!  I couldnt get to the elog and didnt know that the elog was crashing every time I tried to access it. 

But have found other means to access it and the elog is safe for now!

I gave a christmas present to a doubling oven who has been sitting on the PSL table.

The below is a picture of the present I gave. It's a base plate for the doubling oven, made from a block of aluminum, and black-anodized.

The size and the shape are nicely tailored for the combination of the Newfocus kinematic mount and the Covesion oven.

The design had been done by using Solid Works 2010

Here is a picture before he got the present.

Now he looks pretty happy.

This is not such a bad base design, but remember that we have to get a couple of parts with the purple anodize to see if there is a difference between black and purple in terms of the 532 nm reflectivity.

The four IOO PZTs have been turned on in order to confirm the alignment of the IFO.

Once they are turned on, the spots (ITMX/ITMY/PRM/SRM) on the REFL CCD have been easily found.

When the X-arm was aligned to the green beam, it is easily locked to TEM00. Also some LG modes were visible.
i.e. There is some room to improve the mode matching.
The transmitted green at the PSL table is a bit too high and clipped by the first mirror on the table.

No IR flashes were found in either arms.

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

The below are the range and the set values of the strain gauge readback for the PZTs.
When the closed loop buttons are activated the PZTs are fixed at those values, if no one touches the set point dials.

            Min   Max   SetP | Display on the module
PZT1 Yaw    2.20  9.95  6.08 | Broken
PZT1 Pitch -0.011 8.89  4.40 | 1.58

PZT2 Yaw    0.737 9.94  5.37 | 2.17
PZT2 Pitch  0.010 9.42  4.71 | 1.89

Osamu has borrowed an ADC card from the LSC IO chassis (which currently has a flaky generation 2 Host interface board).  He has used it to get his temporary Dell test stand running daqd successfully as of yesterday.

This is mostly a note to myself so I remember this in the new year, assuming Osamu hasn't replaced the evidence by January 7th.

I came in today to check up on the StripTool and burn the Ubuntu LTS (new CDS OS) DVD. I was pretty excited to see the PRM flashes on Mon1.

I waggled the PRM/BS alignments and got a good contrast MICH and then bright flashes in the PRM that totally overload Mon1's CCD.

Now I can see flashes of some IR junk in the X Arm; its way off on the left edge of the mirror, but there's a beam.

For the short term, we can hook up the IO PZTs to some old EPICS channels (like one of the AUX guys in the LSC area), but eventually it has to get hooked up to the new ASC or ASS. We have to bug Joe to see where this shows up in his master diagram.

**Note: if you get lost sometimes when doing the alignments, remember that you can use time_machine_conlog.

Ex:

rossa:general>./time_machine_conlog 2010/12/31,11:00:00 PDT C1:SUS-ITMX_PIT_COMM
Issuing the conlog command:
/cvs/cds/caltech/conlog/bin/conlog +epics -interp at 2010/12/31,11:00:00 PDT "C1:SUS-ITMX_PIT_COMM"


Conlog Replied:

LIGO controls: values at 2010 12/31 11:00:00 pst
 __Epics_Channel_Name______   __value_____
 C1:SUS-ITMX_PIT_COMM         0.406100



Restoring now...

Restoration Successful

Attached is the last 8 days of Vacuum Pressure trend which includes the pumpdown.

 I found that there was no PEM data nor any other data (no SUS or otherwise. No testpoints, no DAQ).

I went through the procedure that Jenne has detailed in the Wiki but it didn't work.

1) Firstly, the 'telnet fb 8088' step doesn't work. It says "Connected to fb.martian" but then just hangs. To replicate the effect of this step I tried ssh'ing to fb and doing a 'pkill daqd'. That works to restart the daqd process.

2) The wiki instructions had a problem. In the GUI step, it should say 'Save' after the Acquire bit has been set to 1. Even so, this works to get the .ini file right and the DTT can see the correct channel list, but none of the channels are available. There are just 'Unable to obtain measurement data'.

3) I tried running 'startc1pem', but no luck. I also tried rebooting c1sus from the command line. That worked so far as to come back up with all the right processes running, but still no data. The actual /frames directory shows that there are frames, but we just can't see the data. I also tried to get data usind the DTT-NDS2 method, but still no luck. (*** ITMX and ITMY both came back with all their filters off; worth checking if their BURTs are working correctly.)

Using DataViewer, however, I AM able to see the data (although the channel name is RED). In fact, I am able to see the trend data ever since I changed the Acquire bit to 1. Plot attached as evidence. Why does DTT not work anymore???

What was the point:

I twiddled with several different things this evening to increase the power into the Mode Cleaner.  The goal was to have enough power to be able to see the arm cavity flashes on the CCD cameras, since it's going to be a total pain to lock the IFO if we can't see what the mode structure looks like.

Summed-up list of what I did:

* Found the MC nicely aligned.  Did not ever adjust the MC suspensions.

* Optimized MC Refl DC, using the old "DMM hooked up to DC out" method.

* Removed the temporary BS1-1064-33-1025-45S that was in the MC refl path, and replaced it with the old BS1-1064-IF-2037-C-45S that used to be there.  This undoes the temporary change from elog 3878.  Note however, that Yuta's elog 3892 says that the original mirror was a 1%, not 10% as the sticker indicates. The temporary mirror was in place to get enough light to MC Refl while the laser power was low, but now we don't want to fry the PD.

* Noticed that the MCWFS path is totally wrong.  Someone (Yuta?) wanted to use the MCWFS as a reference, but the steering mirror in front of WFS1 was switched out, and now no beam goes to WFS2 (it's blocked by part of the mount of the new mirror). I have not yet fixed this, since I wasn't using the WFS tonight, and had other things to get done.  We will need to fix this.

* Realigned the MC Refl path to optimize MC Refl again, with the new mirror.

* Replaced the last steering mirror on the PSL table before the beam goes into the chamber from a BS1-1064-33-1025-45S to a Y1-45S.  I would have liked a Y1-0deg mirror, since the angle is closer to 0 than 45, but I couldn't find one.  According to Mott's elog 2392 the CVI Y1-45S is pretty much equally good all the way down to 0deg, so I went with it.  This undoes the change of keeping the laser power in the chambers to a nice safe ~50mW max while we were at atmosphere.

* Put the HWP in front of the laser back to 267deg, from its temporary place of 240deg.  The rotation was to keep the laser power down while we were at atmosphere.  I put the HWP back to the place that Kevin had determined was best in his elog 3818.

* Tried to quickly align the Xarm by touching the BS, ITMX and ETMX.  I might be seeing IR flashes (I blocked the green beam on the ETMX table so I wouldn't be confused.  I unblocked it before finishing for the night) on the CCD for the Xarm, but that might also be wishful thinking.  There's definitely something lighting up / flashing in the ~center of ETMX on the camera, but I can't decide if it's scatter off of a part of the suspension tower, or if it's really the resonance.  Note to self:  Rana reminds me that the ITM should be misaligned while using BS to get beam on ETM, and then using ETM to get beam on ITM.  Only then should I have realigned the ITM.  I had the ITM aligned (just left where it had been) the whole time, so I was making my life way harder than it should have been.  I'll work on it again more today (Tuesday). 

What happened in the end:

The MC Trans signal on the MC Lock screen went up by almost an order of magnitude (from ~3500 to ~32,000).  When the count was near ~20,000 I could barely see the spot on a card, so I'm not worried about the QPD.  I do wonder, however, if we are saturating the ADC. Suresh changed the transimpedance of the MC Trans QPD a while ago (Suresh's elog 3882), and maybe that was a bad idea? 

Xarm not yet locked. 

Can't really see flashes on the Test Mass cameras. 

- Previously MC TRANS was 9000~10000 when the alignment was good. This means that the MC TRANS PD is saturated if the full power is given.
==> Transimpedance must be changed again.

- Y1-45S has 4% of transmission. Definitively we like to use Y1-0 or anything else. There must be the replaced mirror.
I think Suresh replaced it. So he must remember wher it is.

- We must confirm the beam pointing on the MC mirrors with A2L.

- We must check the MCWFS path alignment and configuration.

- We should take the picture of the new PSL setup in order to update the photo on wiki.

I replaced the final steering mirror (Y1-1037-45-S) in the zig-zag path on the PSL table by a 0 deg mirror Y1-1037-0.

With a sensor card I confirmed the transmission reduced a lot after the replacement.

As we expected, the replacement of the mirror caused a mis-alignment of the incident beam axis to the MC, so I compensated it by touching the angle of the mirror a little bit.

After the alignment of the mirror, the MC is still resonating at TEM00.

We will check the spot positions more accurately by A2L technique.

 Decreased the gain of MC-Trans-Mon QPD ckt

The resistors R1, R2, R3, R4 are now 49.9 kOhm. The previous elog on this subject 3882 has the ckt details. 

I undid Yuta's temporary setup, and put beam back on both WFS.  Since Koji had just aligned the Mode Cleaner, I centered the beam on the WFS using the WFS QPD screen, while watching the WFS Head screen, to make sure that the beam was actually hitting the QPD, and not off in lala land. 

I connected PZT1 and PZT2 to a slow front end machine c1iscaux.

Now we are able to align these PZTs from the control room via epics.

   Since we removed C1ASC that was controlling the voltage applied on the PZTs, we didn't have the controls for them for a long time.

So Rana and I decided to hook them up to an existing slow front end machine temporarily.

(probably the best solution is to connect them to C1LSC, which is fast enough to dither them.)

We actually found that c1iscaux is the proper machine, because it looked like it used to control the PZTs a long long time ago.

Moreover, c1iscaux still has DAC channels named like C1:LSC-PZT1_X, and so on.

  Below shows a screen shot of the medm screen for controlling the PZTs, invoked from a button on sitemap.adl ( pointed by a black arrow in the picture below)

The current default values are all zero at the right top sliders.

I checked the spot positions on MC1 and MC3 by running Yuta's A2L script.

The amounts of the off-centering were good except for YAW of MC1.

 So we have to adjust the YAW alignment of the beam axis by steering the mirrors at the PSL table.

- - - (measured off-centering) - - - 

MC1_PIT  =  -0.711 mm

MC1_YAW =  1.62 mm

MC3_PIT  =   -0.0797 mm

MC3_YAW  =  - 0.223 mm

Google bot  crashed the elog again. Then, I found that Google bot (and I) can crash elogd by trying to show the threaded view.
There looks similar issue reported to the elog forum, the author did not think this is a true bag.

Note: This happens only for the 40m elog. The other elogs (ATF/PSL/TCS/SUS/Cryo) are OK for the threaded view.

 Restarted the elog with the script

[Kiwamu, Jenne]

We successfully aligned the X arm.  No big deal.  Nothing to write in giant colorful letters about.  If we thought it was tricky, we'd be excited.  But since we're rockstar grad students, we can do this anytime, with one hand behind our back.

The details:

Earlier this evening, Kiwamu put a PD at the dark port.  After starting with the usual steering beams around and approximately centering them by finding the beam on the SUS tower, we saw that we could see the fringes on a 'scope hooked up to the dark port's new PD.  We could make the dip in the scope trace go away by misaligning the ETM, so we were confident that it was due to some kind of resonance in the arm.  We then fine-tuned our beam centering by moving the optics in either pitch or yaw until the fringe went away, wrote down the number, then moved the other direction until the fringe went away, and then put the optic back in the middle of those two numbers.  We did the ETM first, then the ITM (because the beam on the PD is sensitive to the ITM pointing, so we didn't want to have to move the ITM very far).  We saw that the cavity had a visibility of ~56% when we had finished with this method.

We then went to look for the flashes transmitted through the ETM.  We were not able to see them on a card, but when we looked with an IR viewer at the back face of the ETM, we could see the flashes. We stole a spare CCD camera found on the PSL table, and the camera power supply from the RefCav Refl camera, and set up a CCD camera with telephoto lens on the ETMX Trans table, looking directly at the back of the ETM.  We hooked the camera up to the regular ETMX camera cable, so we can see the flashes in the control room.  You can see them here:

While the cavity was aligned, here were the slider positions:

Pretty fancy work actually...I wouldn't have guessed that you need to look at the back of the ETM. Does this mean that we can't see the flashes from inside the arm cavity? If so, its a pretty remarkeable statement about the wide angle scatter of the new mirrors. Do we really have 1W going into the MC?

Correct.  We can see the flashes clearly on our new ETM camera, but we see absolutely nothing on the ITM.

Unfortunately, the camera is in the path of the green beam, so we'll have to figure out a more permanent plan.  Right now the laser at the end is shuttered.

Measuring the power now....

Nice, nice!

The power budget for the FPMI is here. The expected Intracavity power and the transmission are at  most ~8W and 100uW, respectively.

[Kiwamu, Jenne]

We have a measely 465mW going into the MC.  We lose a boatload of power on the PZT mirror that is part of the last zigzag for steering into the MC.  Just before this mirror, we measure 1.21W .  Just after this mirror, we measure ~475mW.  Then a teeny bit gets picked off for the PSL POS/ANG.  But we're losing a factor of 3 on this one mirror.  Need to fix!!!!!!!!!

Fixed the 40m elog crashing with the threaded display.

This morning I found that Google bot crashed the elog again. I started the investigation and found the threaded mode is fine if we use the recent 10 entries.

I gradually copied the old entries to a temporary elog and found that a deleted elog entry on August 6 had a corrupted remnant in the elog file. This kept crashed the threaded mode.

Once this entry has been eliminated again, the threaded mode got functional.

I hope this eliminates those frequent elog crashing.

 I checked the triple resonant box for the broadband EOM this afternoon, and found it was healthy.

So I installed it again together with a power combiner and succeeded in locking the MC.

Since the box has a non-50 Ohm input impedance at 29.5 MHz, so it maybe needed to adjust the phase of the LO for the demodulation of the PDH signal.

A good thing is that now we are able to impose the other sidebands (i.e. 11 MHz and 55MHz) via the power combiner.

[Kiwamu, Jenne]

We went this evening in search of a beat note signal between the Xarm transmitted green light and the PSL doubled green light. 

First, we removed our new ETMX camera (we left the mount so it should be easy to put back) from the other day.   We left the test masses exactly where they had been while flashing for IR, so even though we can no longer confirm, we expect that the IR beam axis hasn't changed.  We used the steering mirror on the end table to align the green beam to the cavity.  We turned on the loop to lock the end laser to the cavity, and achieved green lock of the arm.

Then we went to the PSL table to overlap the arm transmitted light with the PSL doubled light.  We made a few changes to the optics that take the arm transmitted light over to the PD.  We found that the arm transmitted light was very high, so we changed from having one steering mirror to having 3 (for table space / geometry reasons we needed 3, not just 2) in order to lower the beam axis.  We also found that the spot size of the arm transmitted beam was ~2x too small, so we changed the mode matching telescope from a 4x reducer to a 2x reducer by changing the 2nd lens from f=50mm to f=100mm (the first lens is f=200mm).  We made the arm transmitted beam and the PSL green beam overlap, but we saw no peak on the spectrum analyzer. 

We checked the temperature of the PSL and end lasers, and determined that we needed to adjust the set temp of the end laser.  However, we still didn't find any beat note.

We then tweaked the temperature of the doubling oven at the end station, to maximize the power transmitted, since Kiwamu said that that had worked in the past.  Alas, no success tonight.

We're stopping for the evening, with the success of reacquiring green lock of the Xarm.

I got a new adapter board for expansion chassis from CDS and exchanged the existing adapter board which was laid on the floor around ETMX to new one.

Then I connected the chassis to c1lcs,  c1lsc seems to be running now. I will return the old board to CDS since Rolf says he wants to return it to manufacture.

 I found an interface box from ADC to D-SUB37pin and a cable to connect them.

I needed to make cables to connect the interface box to existing LSC whitening filters that has a 37 pin female D-SUB connector on one end and a 40pin female flat connector on the other end. We should use shielded cables for them, but unfortunately CDS did not have right one. Temporarily I made one cable for 1-8ch using a ribbon twist cable like Joe did.

I found a saturation at ch5 of ADC0 on c1lsc. I did not check carefully but it seemed to come from the LSC whitening board. Input of ch5 of the whitening board was not terminated and had a huge output voltage, but also ch6 was not terminated and had no big output. I guess something wrong on the LSC whitening board. Needs to be checked. Anyway I unplugged the small ribbon cable between the whitening board and the next LSC AA filter board.

Finally I realized that fiber connection of RFM did not exist. What I saw was the fiber cable of Dolphin. We need a RFM PCIe interface board, and a long fiber cable between c1lsc and RFM hub.

The Watec 902, 1/2" CCD camera got new Tamron lens: 1/2" 10-40mm F/1.4  manual iris. IR corrective lens. It is designed to have the same focal point in the IR as

in the visible light range. However, as the depth of field in the IR range is very narrow, focus adjustment should be done carefully in the IR.

Now you can see the sus tower that will make alignment easier.

 I started reverting Megatron into a standard Ubuntu workstation after Joe/Osamu's attempt to steal it for their real time mumbo jumbo.

First, I installed a hard drive that was sitting around on top of it. That whole area is still a mess; I'm not surprised that we have so many CDS problems in such a chaotic state. There's another drive sitting around there called 'RT Linux' which I didn't use yet.

Second, I removed the ethernet cables and installed a monitor/keyboard/mouse on it.

Then I popped in the Ubuntu 10.04 LTS DVD, wiped the existing CentOS install and started the standard graphical installation of Ubuntu.

Megatron's specs attached: 

There's, as usual, a disconnect between the real martian host table and the one displayed on the Wiki. Basically, the point is: DO NOT TRUST THE WIKI, because people who update the actual host table only randomly update the wiki table.

The only thing worth trusting is the file

/var/named/chroot/var/named/martian.zone
on linux 1.

You will need to have 'root' or 'sudo' to get into that directory to read the file.

Alex and Rolf came over today with a Tempus LX  GPS network timing server.  This has an IRIG-B output and a 1PPS output.  It can also be setup to act as an NTP server (although we did not set that up).

This was placed at waist height in the 1X7 rack.  We took the cable running to the presumably roof mounted antenna from the VME timing board and connected it to this new timing server.  We also moved the source of the 1PPS signal going to the master timer sequencer (big blue box in 1X7 with fibers going to all the front ends) to this new time server.  This system is currently working, although it took about 5 minutes to actually acquire a timing signal from the GPS satellites.  Alex says this system should be more stable, with no time jumps. 

I asked Rolf about the new timing system for the front ends, he had no idea when that hardware would be available to the 40m.

Currently, all the front ends and the frame builder agree on the time.  Front ends are running so the 1 PPS signal appears to be working as well.

While Alex and Rolf were visiting, I pointed out that the Dolphin card was not sending any data, not even a time stamp, from the c1lsc machine.

After some poking around, we realized the IOP (input/output processor) was coming up before the Dolphin driver had even finished loading. 

We uncommented the line

#/etc/dolphin_wait

in the /diskless/root/etc/rc.local file on the frame builder.  This waits until the dolphin module is fully loaded, so it can hand off a correct pointer to the memory location that the Dolphin card reads and writes to.  Previously, the IOP had been receiving a bad pointer since the Dolphin driver had not finished loading.

So now the c1lsc machine can communicate with c1sus via Dolphin and from there the rest of the network via the traditional Ge Fanuc RFM.

[Jenne, Zach, Kiwamu]

 We made some efforts to lock the X arm cavity with the infrared beam.

We eventually obtained the PDH signal from a photo diode at AS port, we are still in the mid way of the lock.

The PDH signal now is going into c1lsc's ADC.

We have to make sure which digital channel corresponds to our PDH signal,

(what we did)

- split the LO signal, which comes from a Marconi, just before the EOM into two path.

     One is going to the EOM and the other is going to the AP table for the demodulation, The driving frequency we are using is 11MHz.

- put RF amplifiers to make the RF signal bigger. The raw signal was small, it was about ~-50 dBm in the spectrum analyzer.

   So we connected two ZLN amplifiers. Now the RF signal is at about 0 dBm

- connected the LO and RF signals to a mixer.  Additionally we put a 9.5-11.5 MHz bandpass filter at the LO path since there was some amounts of 29.5MHz due to the RF reflection at the EOM resonant box.

     After a low pass filter by SR560 the signal shows typical PDH behaviors.

- strung a BNC cable which connects the demodulated signal and c1lsc.

    In order to connect the signal to the current working ADC, we disconnected AS166_I from a whitening board and plug our cable on it.

- tried checking the digital signal but we somehow couldn't configure DAQ setting, So actually we couldn't make sure which channel corresponds to our signal.

Joe updated the rga procedure in the wiki and we turned on the filament. It will take a few days to reach thermal equilibrium.

TP2 dry fore pump was replaced at 910mTorr

[Joe, Kiwamu]

We modified the activateDAQ.py script which lives in /opt/rtcds/caltech/c1/chans/daq/ and updates the C1SUS.ini, C1MCS.ini, C1RMS.ini, C1SCX.ini and C1SCY.ini files.  These files contain the DAQ channels for all the optics.

It has been modified so that channels like C1:SUS-ITMX_ULSEN_OUT_DAQ become C1:SUS-ITMX_SENSOR_UL.  Similarly the oplev signals go from C1:SUS-ITMX_OLPIT_OUT to C1:SUS-ITMX_OPLEV_PERROR.

After some debugging, we ran the script successfully and checked the output was correct.  We then restarted the frame builder (telnet fb 8088 and then shutdown) and also hit the DAQ reload button for all the front ends.

I tested in dataviewer that I could go back several years as well as going back just 1 hour in the history and see data for C1:SUS-ITMX_SENSOR_LL as well as C1:SUS-ITMX_OPLEV_YERROR.  I also tested realtime is also working for these channels.

The contents of the script are below.

inputfiles=["C1SUS.ini","C1RMS.ini","C1MCS.ini","C1SCX.ini","C1SCY.ini"]
prefix="[C1:SUS-"
optics=["BS_","ITMX_","ITMY_","PRM_","SRM_","MC1_","MC1_","MC2_","MC3_","ETMX_"]
#channels=["SUSPOS_IN1","SUSPIT_IN1","SUSYAW_IN1","SUSSIDE_IN1","ULSEN_OUT","URSEN_OUT","LRSEN_OUT","LLSEN_OUT","SDSEN_OUT","OL_SUM_IN1","OLPIT_IN1","OLYAW_IN1"]
channels_dict = {'SUSPOS_IN1':'SUSPOS_IN1_DAQ',
'SUSPIT_IN1':'SUSPIT_IN1_DAQ',
'SUSYAW_IN1':'SUSYAW_IN1_DAQ',
'SUSSIDE_IN1':'SUSSIDE_IN1_DAQ',
'ULSEN_OUT':'SENSOR_UL',
'URSEN_OUT':'SENSOR_UR',
'LRSEN_OUT':'SENSOR_LR',
'LLSEN_OUT':'SENSOR_LL',
'SDSEN_OUT':'SENSOR_SIDE',
'OLPIT_OUT':'OPLEV_PERROR',
'OLYAW_OUT':'OPLEV_YERROR',
'OL_SUM_OUT':'OPLEV_SUM'}

suffix="_DAQ]\n"

## set datarate
datarate=2048

## read the ini files
for inputfile in inputfiles:
    print inputfile
    outputfile=inputfile
    ifile = open(inputfile,'r')
    lines = ifile.readlines()
    ifile.close()

    for k in range(len(lines)):
        for op in optics:
            for ch in channels_dict:
                if (prefix+op+ch+suffix) in lines[k]:
                    lines[k]=prefix + op + channels_dict[ch] + "]\n"
                    lines[k+1]=lines[k+1].lstrip("#").rstrip(lines[k+1].split("=")[1])+"1\n"
                    lines[k+2]=lines[k+2].lstrip("#")
                    lines[k+3]=lines[k+3].lstrip("#").rstrip(lines[k+3].split("=")[1])+str(datarate)+"\n"
                    lines[k+4]=lines[k+4].lstrip("#")
    ofile = open(outputfile,'w')
    for k in range(len(lines)):
        ofile.write(lines[k])
        #print lines[k]
    ofile.close()


I created two simple cron jobs, one running on linux1 and one running on nodus, to produce an updated copy of the martian host table linkable from the wiki every day.

The scripts live in /opt/rtcds/caltech/c1/scripts/AutoUpdate/.  One is called  updateHostTable.cron and run on linux1 everyday at 4 am, and the other is called moveHostTable.cron which is run on nodus everyday at 5am.

The new link has been added to the Martian Host table wiki page  here.

I wrote a new script that is in /opt/rtcds/caltech/c1/scripts/AutoUpdate/ called  webview_simlink_update.m. 

This m-file when run in matlab will go to the /opt/rtcds/caltech/c1/target directory and for each c1 front end, generate the corresponding webview files for that system and place them in the AutoUpdate directory. 

Afterwards the files can be moved on Nodus to the /users/public_html/FE/ directory with:

mv /opt/rtcds/caltech/c1/scripts/AutoUpdate/*slwebview* /users/public_html/FE/

This was run today, and the files can be viewed at:

https://nodus.ligo.caltech.edu:30889/FE/

Long term, I'd like to figure out a way of automating this to produce automatically updated screens without having to run it manually.  However, simulink seems to stubbornly require an X window to work.

[Larisa and Jenne]

We wanted to get rid of the awkward cart that was sitting behind the 1Y1 rack.  This cart was supplying a +5V offset to the PZT driver, so that we could use the MC length signal to feedback to lock the laser to the MC cavity.  Instead, we put the offset on the last op amp before the servo out on the Mc Servo Board.  Because we wanted +5V, but the board only had +5, +15, -15V as options, and we needed -5 to add just before the op amp (U40 in the schematic), because the op amp is using regular negative feedback, we made a little voltage divider between -15V and GND, to give ourselves -5V.  We used the back side of the voltage test points (where you can check to make sure that you're actually getting DC voltage on the board), and used a 511Ohm and 1.02kOhm resistor as a voltage divider. 

Then we put a 3.32kOhm resistor in ~"parallel" to R124, which is the usual resistor just before the negative input of the op amp.  Our -5V goes to our new resistor, and should, at the output, give us a +5V offset. 

Sadly, when we measure the actual output we get, it's only +2.3V.  Sadface.

We went ahead and plugged the servo out into the PZT driver anyway, since we had previously seen that the fluctuation when the mode cleaner is locked was much less than a volt, so we won't run into any problems with the PZT driver running into the lower limit (it only goes 0-10V).

Suresh has discovered that the op amp that we're looking at, U40 on the schematic, is an AD829, which has an input impedance of a measely 13kOhm.  So maybe the 3.32kOhm resistors that we are using (because that's what had already been there) are too large.  Perhaps tomorrow I'll switch all 3 resistors (R119, R124, and our new one) to something more like 1kOhm.  But right now, the MC is locked, and I'm super hungry, and it's time for some arm locking action.

I've attached the schematic.  The stuff that we fitzed with was all on page 8.

I can not think of any reason that the input impedance of 13kOhm between the pos/neg inputs produces such a big change at the output. In any case, the differential voltage between the pos/neg inputs produces a big output. But the output was just 2V or so. This means that the neg input was actually about zero volt. This ensures the principle of the summing amplifier of this kind.

Because the input impedance of the summing node (the additional resister you put at the negative input) is not infinity, the voltage divider is not perfect and shows 10% reduction of the voltge (i.e. the output will have +4.5V offset instead of +5V). But still it is not enough to explain such a small output like 2.3V.

What I can think of is that the earlier stages somehow have the offset for some reason. Anyway, it is difficult to guess the true reason unless all of the nodes around the last stage are checked with the multimeters.

At least, we can remove the voltage divider and instead put a 10k between -15V and the neg input in order to impose +5V offset at the output. This costs 1.5mA instead of 10mA.

[Suresh, Kiwamu]

 We eventually succeeded in locking X arm with the infrared beam.

The PDH signal is taken at MCL's ADC instead of c1lsc's, and fedback to MC2_POS through the MCL path.

Right now the lock is not so stable for some reasons, so we need to investigate it more.

(what we did)

 - strung a long BNC cable to connect the demodulated signal and the ADC of c1ioo.

          We didn't touch anything on the demodulation system, so the setup for the demodulation is exactly the same as that of yesterday (see here).

 - disconnected the actual MCL cable from the ADC breakout board at 1X2 rack. And put the demodulated signal onto it.

 - checked the analog dewhitening filter state for the MC2 coil driver, found the analog filter are always off.

  So we just made simDW and invDW always on.

- changed the gain of the MCL loop to have a stable lock for the X arm.

    right now a reasonable setup in the MCL filters are:

         FM1:ON, FM10:ON, G=0.1

 - In fact the lock of the MC is not so stable compared to before, frequently an attempt of locking the X arm leads to the unlock of the MC.

[Rana, Kiwamu]

Here is the list for the daytime tasks of tomorrow, Jan. 12th.

The daytime task is a work basically to be done or quitted before the sun goes down.

Along with the tasks, we roughly assigned the people who are responsible for it.

The tasks below are basically separated from each other, so we can work in parallel.

--- 1.  LSC analog interface check (Joe/Koji)

   * check whitening filter

   * demodulation board check

    * check ADC connections

--- 2.  MC2 coil Dewhitening (Joe)

    * fix binary outputs.

    * FM9 must be the trigger of the binary outputs instead of FM10.

--- 3. 11MHz modulation depth (Kiwamu)

   * investigate why the depth is so low

--- 4. PEM DAQ name issue (Jenne)

   * change the name of seismic channels properly so that we can deal with the calibrated stuff

--- 5. phase adjustment for MC-PDH locking (Suresh)

--- 6. medm screens for C1LSC ()

    * make screens

[josephb, osamu, kiwamu]

We worked over by the 1Y2 rack today, trying to debug why we didn't get any signal to the c1lsc ADC.

We turned off the power to the rack several times while examining cards, including the whitening filter board, AA board, and the REFL 33 demod board.  I will note, I incorrectly turned off power in the 1Y1 rack briefly. 

We noticed a small wire on the whitening filter board on the channel 5 path.  Rana suggested this was to part of a fix for the channels 4 and 5 having too much cross talk.  A trace was cut and this jumper added to fix that particular problem.

We confirmed would could pass signals through each individual channel on the AA and whitening filter boards.  When we put them back in, we did noticed a large offset when the inputs were not terminated.  After terminating all inputs, values at the ADC were reasonable, measuring on from 0 to about -20 counts.  We applied a 1 Hz, 0.1 Vpp signal and confirmed we saw the digital controls respond back with the correct sine wave.

We examined the REFL 33 demod board and confirmed it would work for demodulating 11 MHZ, although without tuning, the I and Q phases will not be exactly 90 degrees apart.

The REFL 33  I and Q outputs have been connected to the whitening board's 1 and 2 inputs, respectively.  Once Kiwamu  adds approriate LO and PD signals to the REFL 33 demod board he should be able to see the resulting I and Q signals digitally on the PD1 I and Q channels.

In an unrelated fix, we examined the suspensions screens, specifically the Dewhitening lights.  Turns out the lights were still looking at SW2 bit 7 instead of SW2 bit 5.  The actual front end models were using the correct bit (21 which corresponds to the 9th filter bank), so this was purely a display issue.  Tomorrow I'll take a look at the binary outputs and see why the analog filters aren't actually changing.

[Koji Suresh Kiwamu]

Suresh modified the MC board to have +5V offset at the output. (To be reported in the separated elog)

The MC lock has not been obtained at this point. An investigation revealed that there was very small (~5mVpp) PDH signal.

Kiwamu removed his triple resonant adapter and put the 50Ohm termination insted.
This restored the signal level normal although this changed the demodulation phase about 20deg.
We left the demodulation phase as it is because this is a temporary setup and the loss of the signal is not significant.

Now the MC is steadily locked with the single super boost.

I briefly checked the MC2 analog dewhitening filters.

It turned out that the switching of the dewhitening filters from epics worked correctly except for the UR path.

I couldn't get a healthy transfer function for the UR path probably because the UR monitor at the front panel on either the AI filter or the dewhitening filter maybe broken.

Need a check again.