Steve, Jenne, Koji

The PSL was blocked by the shutter and the manual block.
We started venting at 9:30

09:30  25 torr
10:30 180 torr
11:00 230 torr
12:00 380 torr
13:00 520 torr
14:30 680 torr - Finish. It is already over pressured.

1. PSL had stayed on overnight. There was an EQ (M 4.6 near Costa Rica) which showed up on the Seis BLRMS, and I noticed that several optics were reporting Oplev spots off their QPDs (I had just centered these yesterday). So I did a quick alignment check:
   • IMC was readily locked
   • After moving test mass bias sliders to bring Oplev spots back to the center, the EX and EY green beams were readily locked to a TEM00 mode
   • IR flashes could be seen in TRX and TRY (though their levels are low, since we are operating with 1/10th the nominal power
   • The IP-POS QPD channels were reporting a "segmentation fault" so I keyed the c1iscaux crate and they came back. Still the QPD was reporting a low SUM value, but this too is because of the lower power. Conveniently, there was an ND2.0 filter in the beam path on a flip mount which I just flipped out of the way for the low-power tracking.
   • Then, PSL and green shutters were closed and Oplev loops were disengaged.
2. Checked that we have an RGA scan from today
3. During the walkthrough to check the jam nuts, Chub noticed that the outer nuts on the bellows between the OMC chamber and the IMC chamber were loose to the finger! He is tightening them now and checking the remaining jam nuts. AFAIK, Steve made it sound like this was always a formality. Should we be concerned? The other jam nuts are fine according to Chub.
4. We valved off the pumpspool from the main volume and annuli, and started letting Nitrogen into the main volume at ~1045am.
5. Started letting instrument grade air into the main volume at ~1130am. We are aiming for a pressure increase of 3 torr/min
6. 4 cylinders of dry air were exhausted by ~330pm. It actually looks like we over-pressured the main volume by ~20torr - this is bad, we should've stopped the air inletting at 700 psi and then let it equilibriate to lab air pressure.
7. At some point during the vent, the main volume pressure exceeded the working range of the cold cathode gauge CC1. It reports "Current Fail" on its LED display, which I'm assuming meant it auto-shutoff its HV to protect itself, Jon tells me the vacuum code isn't responsible for initiating any manual shutoff.
8. A new vacuum state was added to reflect these conditions (pumpspool under vacuum, main volume at atmosphere).
9. The annuli remain under vacuum for now. Tomorrow, when we remove the EY door, we will vent the EY annulus.

IMC was locked, MC2T ~ 1200cts after some alginment touch ups. The test mass oplevs indicate some drift, ~100urad. I didn't realign them.

The EY door removal will only be done tomorrow. I will take some free-swinging ETMY data today (suspension was kicked at 1241919438) to see if anything has changed (it shouldn't have). I need to think up a systematic debugging plan in the meantime.

Today so far:

• I moved SRM forward by 3mm
• Then I leveled the ITMY table 
• At this point, bringing the ITMY oplev beam back onto its QPD got me back to green locking and IR flashes 
• AS and POY beams are both making it out to their tables, as seen by IR card. (Though not to their in-air optics)

Here's my quick brain dump of things to do before we can pump down (anyone see anything missing?):

• Check the clearance of the POY beam at the SRM cage
• Re-do distance reconstruction measurements, confirm desired SRC length
• Lock the SRM cage down fully (right now, has 2 clamps on, and one laying unused)
• Align SRM for SRC flashes
• Adjust SRM OSEM positions as needed
• Adjust SRM oplev beam path, measure lever arm for calibration
• Confirm beam spots on output mirrors in ITMY and BS chambers are ok
• Take pictures of ITMY chamber. 
• Closeup checklist

POY has >2 inches of clearance from the SRM cage. 

Distance reconstruction indicates an SRC length of 5399mm, which was exactly our target. 

 [Koji, ericq]

We have completed the above points; the ITMY table is still level.

Despite what the wiki says, the SRM LR OSEM open voltage is ~1.97V instead of ~1.64, so we shot for half of that. 

The in-air steering of the SRM oplev return beam needs adjustment. I'll estimate the beam path length when I'm taking pictures and closing up. 

Left to do:

• Now that AS is back on diode, lock arms and align everything. Confirm everyone's happiness. 
• Take numerous pictures of ITMY chamber.
• Center oplevs
• Put doors on
• Close shutters
• Pump down
• Replace MC refl Y1 with the beamsplitter
• Turn PSL power back up

Related In-Air work:

• Fix POY steering
• Fix SRM oplev return steering

Everything is aligned, AS and POY make it out of vacuum unclipped, OSEM readings look good.

I set up the SRM oplev, centered all oplevs.

Tomorrow, we just have to take pictures of the ITMY chamber before we put the heavy doors on. 

I closed the PSL shutter as we didn't want to burn the mirror surface when we are not working.

Photos have been taken of the ITMY chamber, and uploaded to picasa. Here's a slideshow:

 [Steve, Eric]

I've been helping Steve vent this morning. The following things were done (from Steve's logbook):

• Particle counts: 0.5 micron particles, 4200 counts per cubic ft
• Vertex crane drive checked to be ok
• Optical Levers set for local damping only
• Saved some screens
• PSL shutter and green shutters closed
• HV Off checked, JAM nuts checked
• Vac: Close V1, VM1, ans - VA6, open VM3 - RGA, cond: chamber open mode
• 8AM: VV1 open to N2, regulator set  to 14 psi
• 8:23AM: 35psi Instrument grade Air

(At this point, I took over the air canisters, while Steve made preparations around the lab. 

• 9:00AM: 2nd air cylinder, 14 psi 
• 9:40AM: 3rd air cyl
• 10:20AM: 4th air cyl
• 11:00AM: 5th air cyl

With the 5th cylinder, we began approaching 1 atm, so we slowed the regulator down to 5psi. Around 750 torr, Steve opened VV1 to air.

According to Steve, we will be at atmospheric pressure at  ~12:30pm.

I was poking around at the LSC rack to try and set up a temporary arrangement whereby I take the signals from the DAC differentially and route them to the D990694 differentially. The situation is complicated by the fact that, afaik, we don't have any break out boards for the DIN96 connectors on the back of all our Eurocrate cards (or indeed for many of the other funky connecters we have like IDE/IDC 10,50 etc etc). I've asked Steve to look into ordering a few of these. So I tried to put together a hacky solution with an expansion card and an IDC64 connector. I must have accidentally shorted a pair of DAC pins or something, because all models on the c1lsc FE crashed. On attempting to restart them (c1lsc was still ssh-able), the usual issue of all vertex FEs crashing happened. It required several iterations of me walking into the lab to hard-reboot FEs, but everything is back green now, and I see the AS beam on the camera so the input pointing of the TTs is roughly back where it was. Y arm TEM00 flashes are also seen. I'm not going to re-align the IFO tonight. Maybe I'll stick to using a function generator for the THD tests, probably routing non AI-ed signals directly is as bad as any timing asynchronicity between funcGen and DAQ system...

Summary:

Around 5pm local time, the three vertex FEs crashed. AFAIK, no one was in the lab or working on anything CDS related, so this is worrying.

Details:

• Reboot script was used to bring all FEs back - only soft reboots were required.
• The IMC and arms can now be locked.
• I think combination of burt + SDF would have reverted all the settings as they should be, but if something appears off, it could be that some EPICS value didn't get reset correctly.

 3 of the 4 remote controlled illuminators at the vertex are installed and can now be turned on via sitemap. There are a total of 15 controls for "Illum", but only the 3 labeled with MC, BS-PRM and ITMY-SRM are functional.

As marked up in the photos.

Attachment 5: The electronics units removed. Cleaning half way down. (KA)

Attachment 6: Moved most of the units to 1X3B rack ELOG 17125 (KA)

The analog electronics units piled up along the wall was moved into 1X3B rack which was basically empty. (Attachments 1/2/4)

We had a couple of unused Sun Machines. I salvaged VMIC cards (RFM and Fast fiber networking? for DAQ???) and gave them to Tega.
Attachment 3 shows the eWastes collected this afternoon.

 I shut down damping to the Vertex optics and removed Binary IO  Adapter chassy BO0 and BO1

About a week ago I discussed the BO0's power indicator lights with Kiwamu. They were  not on or they were blinking on-off.

I put screws into ps connectors in the back, but it did not helped.

[Jamie, Koji]

- We found the reason why some of the LEDs had no light. It was because the LEDs were blown as they were directly connected to the power supply.
The LEDs are presumably designed to be connected to a 5V supply (with internal current-limiting resistor of ~500Ohm). The too much current
with the 15V (~30mA) made the LED blown, or the life-time of them shorter.

- Jamie removed all of the BO modules and I put 800Ohm additional resister such that the resultant current is to be 12mA.
The LEDs were tested and are fine now.

- The four BO boxes for C1SUS were restored on the rack. I personally got confused what should be connected where
even though I had labeled for BO0 and BO1. I just have connected CH1-16 for BO0. The power supplies have been connected only to BO0 and BO1.

- I tested the whitening of PRM UL sensor by exciting PRM UL sensor. The transfer function told us that the pendulum response can be seen
up to 10-15Hz. When the whitening is on, I could see the change of the transfer function in that freq band. This is good.
So the main reason why I could not see theis was that the power supply for the BOs were not turned on.

- I suppose Jamie/Joe will restore all of the BO boxes on the racks tomorrow. I am going to make a test script for checking the PD whitenings.

- I was investigating the SUS whitening issue.

- I could not find any suspension which can handle the input whitening switch correctly.

- I went to 1X5 rack and found that both of the two binary output boxes were turned off.
As far as I know they are pulling up the lines which are switched by the open collector outputs.

- I tried to turn on the switch. Immediately I noticed the power lamps did not work. So I need an isolated setup to investigate the situation.

- The cables are labelled. I will ask steve to remove the boxes from the rack.

4 units of Vertex SUS DAC adapter (https://dcc.ligo.org/LIGO-D2100035) ready.

https://dcc.ligo.org/LIGO-S2101689

https://dcc.ligo.org/LIGO-S2101690

https://dcc.ligo.org/LIGO-S2101691

https://dcc.ligo.org/LIGO-S2101692

The units are completely passive right now and has option to extend to have a dewhitening board added inside.
So the power switch does nothing.

Some of the components for the dewhitening enhancement are attached inside the units.

I've now made a collection of sensing matrix measurements. 

In all of the plots below, the radial scale is logarithmic, each grid line is a factor of 10. The units of the radial direction are calibrated into demod board output Volts per meter. The same radial scale is used on all plots and subplots.

I did two PRMI measurements: with MICH locked and excited with either the ITMS or the BS + PRM compensation. This tells us if our PRM compensation is working; I think it is indeed ok. I though I remembered that we came up with a number for the SRM compensation, but I haven't been able to find it yet. 

The CARM sensing int he PRFPMI measurement has the loop gain at the excitation frequency undone. All excitations were simultaneously notched out of all control filters, via the NotchSensMat filters. 

The angular scale is set to the analog I and Q signals; the dotted lines show the digitial phase rotation angle used at the time of measurement. 

The Vertex crane is smarter and safer now.  This upgrade ensures that the two sections of I-beam (8ft, 4ft) remain firmly latched to form a straight member till the latch is released.

In specific, it ensures that problems such as this one do not occur in the future.

The new safety features are:

When the I-beam sections are latched together, a pneumatic piston ensures that the latch is secure. 

If the latch is not engaged the trolley does not move outward beyond the end of the 8-foot section of the I beam.

If the trolley is out on the 4-foot section of the beam then we cannot disengage the latch.

How does it work?

The state of the Limit Switch 1 changes when the trolly goes past it.    The Limit Switch 2 gets pressed when the two sections are latched together.

The pneumatic piston raises or lowers the latch.  The Pneumatic Latch Switch operates a pneumatic valve controlling the state of the piston.

The new controller now has Pneumatic Latch Switch in addition to the usual Start, Stop, Up, Down, In and Out buttons. 

Each of the Up, Down, In and Out buttons have two operational states:  Half pressed (low speed) and Full pressed (High Speed).  Their functions remain the same as before.

The new Pneumatic Switch:

When this switch is 'Engaged' and the 4 ft section is swung in-line with the 8 ft section, the two sections get latched together.

To unlatch them we have to throw the switch into the 'Disengage' state.  This makes the piston push the latch open and a spring rotates the 4 ft section about its pivot.

Limit Switch 2 is not pressed (I-beams not aligned straight) ==> Limit Switch 1 will prevent the trolley from out going beyond the 8 ft section.

While Limit Switch 2 is pressed we cannot disengage the latch.

Note: 

   The pneumatic piston requires 80psi of pressure to operate.  However we have only 40psi in the lab and the piston seems to operate quite well at this pressure as well.  I believe a request has been made to get an 80psi line laid just for this application.

Jon and I were surveying the CDS situation so that he can prepare a report for discussion with Rolf/Rich about our upcoming BHD upgrade. In our poking around, we must have bumped something somewhere because the c1ioo machine went offline, and consequently, took all the vertex models out. I rebooted everything with the reboot script, everything seems to have come back smoothly. I took this opportunity to install some saturation counters for the arm servos, as we have for the CARM/DARM loops, because I want to use these for a watch script that catches when the ALS loses lock and shuts stuff off before kicking optics around needlessly. See Attachment #1 for my changes.

Very encouraging results from the test last night.  The new configuration did not crash once overnight, and seemed to write out full, second trend, and minute trend frames without issue.  However, full validity of all the written out frames has not been confirmed.

overview

The configuration under test involves two separate daqd binaries instead of one.  We usually run with what is referred to as a "framebuilder" (fb) configuration:

• fb: a single daqd binary that:
  • collect the data from the front ends
  • coallate full data into frame file format
  • calculates trend data
  • writes frame files to disk.

The current configuration separates the tasks into multiple separate binaries: a "data concentrator" (dc) and a "frame writer" (fw):

• dc:
  • collect data from front ends
  • coallate full data into frame file format
  • broadcasts frame files over local network
• fw:
  • receives frame files from broadcast
  • calculates trend data
  • writes frame files to disk

This configuration is more like what is run at the sites, where all the various components are separate and run on separate hardware.  In our case, I tried just running the two binaries on the same machine, with the broadcast going over the loopback interface.  None of the systems that use separated daqd tasks see the failures that we've been seeing with the all-in-one fb configuration (and other sites like AEI have also seen).

My guess  is that there's some busted semaphore somewhere in daqd that's being shared between the concentrator and writer components.  The writer component probably aquires the lock while it's writing out the frame, which prevents the concentrator for doing what it needs to be doing while the frame is being written out.  That causes the concentrator to lock up and die if the frame writing takes too long (which it seems to almost necessarily do, especially when trend frames are also being written out).

results

The current configuration hasn't been tweaked or optimized at all.  There is of course basically no documentation on the meaning of the various daqdrc directives.  Hopefully I can get Keith Thorne to help me figure out a well optimized configuration.

There is at least one problem whereby the fw component is issuing an excessively large number of re-transmission requests:

2016-06-15_09:46:22 [Wed Jun 15 09:46:22 2016] Ask for retransmission of 6 packets; port 7097
2016-06-15_09:46:22 [Wed Jun 15 09:46:22 2016] Ask for retransmission of 8 packets; port 7097
2016-06-15_09:46:22 [Wed Jun 15 09:46:22 2016] Ask for retransmission of 3 packets; port 7097
2016-06-15_09:46:22 [Wed Jun 15 09:46:22 2016] Ask for retransmission of 5 packets; port 7097
2016-06-15_09:46:22 [Wed Jun 15 09:46:22 2016] Ask for retransmission of 5 packets; port 7097
2016-06-15_09:46:22 [Wed Jun 15 09:46:22 2016] Ask for retransmission of 5 packets; port 7097
2016-06-15_09:46:22 [Wed Jun 15 09:46:22 2016] Ask for retransmission of 5 packets; port 7097
2016-06-15_09:46:22 [Wed Jun 15 09:46:22 2016] Ask for retransmission of 6 packets; port 7097
2016-06-15_09:46:23 [Wed Jun 15 09:46:23 2016] Ask for retransmission of 1 packets; port 7097

It's unclear why.  Presumably the retransmissions requests are being honored, and the fw eventually gets the data it needs.  Otherwise I would hope that there would be the appropriate errors.

The data is being written out as expected:

 full/11500: total 182G
drwxr-xr-x  2 controls controls 132K Jun 15 09:37 .
-rw-r--r--  1 controls controls  69M Jun 15 09:37 C-R-1150043856-16.gwf
-rw-r--r--  1 controls controls  68M Jun 15 09:37 C-R-1150043840-16.gwf
-rw-r--r--  1 controls controls  68M Jun 15 09:37 C-R-1150043824-16.gwf
-rw-r--r--  1 controls controls  69M Jun 15 09:36 C-R-1150043808-16.gwf
-rw-r--r--  1 controls controls  69M Jun 15 09:36 C-R-1150043792-16.gwf
-rw-r--r--  1 controls controls  68M Jun 15 09:36 C-R-1150043776-16.gwf
-rw-r--r--  1 controls controls  68M Jun 15 09:36 C-R-1150043760-16.gwf
-rw-r--r--  1 controls controls  69M Jun 15 09:35 C-R-1150043744-16.gwf

 trend/second/11500: total 11G
drwxr-xr-x  2 controls controls 4.0K Jun 15 09:29 .
-rw-r--r--  1 controls controls 148M Jun 15 09:29 C-T-1150042800-600.gwf
-rw-r--r--  1 controls controls 148M Jun 15 09:19 C-T-1150042200-600.gwf
-rw-r--r--  1 controls controls 148M Jun 15 09:09 C-T-1150041600-600.gwf
-rw-r--r--  1 controls controls 148M Jun 15 08:59 C-T-1150041000-600.gwf
-rw-r--r--  1 controls controls 148M Jun 15 08:49 C-T-1150040400-600.gwf
-rw-r--r--  1 controls controls 148M Jun 15 08:39 C-T-1150039800-600.gwf
-rw-r--r--  1 controls controls 148M Jun 15 08:29 C-T-1150039200-600.gwf
-rw-r--r--  1 controls controls 148M Jun 15 08:19 C-T-1150038600-600.gwf

 trend/minute/11500: total 152M
drwxr-xr-x 2 controls controls 4.0K Jun 15 07:27 .
-rw-r--r-- 1 controls controls  51M Jun 15 07:27 C-M-1150023600-7200.gwf
-rw-r--r-- 1 controls controls  51M Jun 15 04:31 C-M-1150012800-7200.gwf
-rw-r--r-- 1 controls controls  51M Jun 15 01:27 C-M-1150002000-7200.gwf

The frame sizes look more or less as expected, and they seem to be valid as determined with some quick checks with the framecpp command line utilities.

[Larisa, Aidan,Steve,Suresh]

   Today was the first session for implementing the new video cabling plan laid out in the document " CCD_Cable_Upgrade_Plan_Jan11_2011.pdf"  by Joon Ho attached to his elog entry 4139.  We started to check and label all the existing cables according to the new naming scheme. 

So far we have labeled the following cables. Each has been checked by connecting it to a monitor near the Video Mux and a camera at the other end.

C1:IO VIDEO 8ETMYF

C1:IO-VIDEO 6 ITMYF

C1:IO-VIDEO 21 SRMF

C1:IO-VIDEO 25 OMCT

C1:IO-VIDEO 19 REFL

C1:IO-VIDEO 22 AS

C1:IO-VIDEO 18 IMCR

C1:IO-VIDEO 14 PMCT

C1:IO-VIDEO 12 RCT

C1:IO-VIDEO 9 ETMXF

C1:IO-VIDEO 1 MC2T

Next we need to continue and finish the labeling of existing cables.  We then choose a specific set of cables which need to be laid together and proceed to lay them after attaching suitable lables to them.

Steve is summarizing the Video Matrix choices into this Wiki page:

http://lhocds.ligo-wa.caltech.edu:8000/40m/Electronics/VideoMUX

Requirements:

Price: < 5k$

Control: RS-232 and Ethernet

Interface: BNC (Composite Video)

Please check into the page on Monday for a final list of choices and add comments to the wiki page.

 [Kiwamu, Larisa]

The following Video MUX inputs(cameras) and outputs(monitors) have been checked:

MC2F, FI, AS Spare, ITMYF, ITMXF, ETMYF, ETMXF, PSL Spare, ETMXT, MC2T, POP, MC1F/MC3F, SRMF, ETMYT, PRM/BS, CRT1(MON1), ETMY Monitor, CRT2(MON2), CRT4(MON4), MC1 Monitor, CRT3(MON3), PSL1 Monitor, PSL2 Monitor, CRT6(MON6), CRT5(MON5), ETMX Monitor, MC2 Monitor, CRT9, CRT7(MON7), CRT10, and Projector.

Their respective statuses have been updated on the wiki:   (wiki is down at the moment, I will come back and add the link when it's back up)

Now the video matrix is responding correctly and the web interface shows up. (Attachment 1)

Also the video buttons respond as usual. I pushed Locking Template button to bring the setting back to nominal. (Attachment 2)

In this video: https://youtu.be/iphcyNWFD10, the comments focus on the orange crocs, my wrinkled shirt, and the first aid kit.

What mode will you get if lock the cavity PRM - ITMY/ITMX/TEST MIRROR without PR2, PR3 and BS?

Is it possible to skip MC1, MC3 and lock the laser to this test cavity to make sure that this is not actuator/electronics noise?

I think Den accidentally edited and overwrote my entry, rather than replying, so I'm going to recreate it from memory:

I aligned the PRM-flat test cavity (although not as well as Jamie and Koji did later in the evening) and took some videos. Note that these may not be as relevant any more, since Jamie and Koji improved things after I left.

Also, before doing anything with the cavity, I tuned up the PMC since the pitch input alignment wasn't perfect (we were getting ~0.7 transmission), and also tuned up the MC alignment and remeasured the MC spot positions, to maintain a record.

 Composite video matrix switchers with 32 BNC in and 32 BNC channels out are listed.

Long time ago, I looked at the manual of the video switcher.
http://media.extron.com/download/files/userman/Plus_Ultra_MAV_C.pdf
Here is the summary. This will be the basic of the more sophisticated switching program which may have GUI.

In principle, you can manually control the matrix via telnet. At the console machines, you can connect to the matrix using telnet

telnet 192.168.113.92

This opens TCP/IP port 23 of the specified machine. You will receive some messages.
Then type some command like:
--------------------

• 1*2!       (connect input#1 to output#2)
• 1,           (save the current setting into preset1)
• 1.           (restore the setting from preset1)

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

Basicaly that's all. There are many other features but I don't think we need them.

We can create a simple program with any of the language as any of the language has the capability of the TCP/IP connection.
e.g. C, Perl, Python. Tcl/Tk
Any of them are fine.

Now what we have to think about is how to implement the interface in the epics screen (or whatever).
It needs some investigation how the people is thinking as the ideal interface.
But, first of all, you should make the above three operations available as a simple UNIX command like:

videoswitch -i 192.168.113.92 1 2
videoswitch -i 192.168.113.92 -store 1
videoswitch -i 192.168.113.92 -recall 1
(There is no such command yet. These are showing what it should be!)

This can be done by a single day work and our life will be much better.

I have made a small python script to handle the video matrix.

It is too far from the perfection, but I release it as it is already useful in some extent.

The script is in the /cvs/cds/rtcds/caltech/c1/scripts/general directory.

usage:

videoswitch.py in_ch_name out_ch_name


in_ch_name is one of the followings

MC2F, IFOPO, OMCR, FI, AS_Spare, ITMYF, ITMXF, ETMYF, ETMXF,
PMCR, RCR, RCT, PSL_Spare, PMCT, ETMXT, MC2T, POP, IMCR, REFL,
MC1F, SRMF, AS, ETMYT, PRM, OMCT, Quad1, Quad2, Quad3

out_ch_name is one of the followings

Mon1, Mon2, Mon3, Mon4, Mon5, Mon6, Mon7,
ETMY, MC1, PSL1, PSL2, ETMX, MC2, CRT9,CRT10,Projector,
Quad1_1, Quad1_2, Quad1_3, Quad1_4,
Quad2_1, Quad2_2, Quad2_3, Quad2_4,
Quad3_1, Quad3_2, Quad3_3, Quad3_4


[Jamie, Jenne]

Koji and Jamie locked the PRMI, and then Jamie and I took some videos. 

Video 1:   https://www.youtube.com/watch?v=jszTeyETyxU shows the face of PR2.

Video 2:   https://www.youtube.com/watch?v=Tfi4I4Q3Mqw shows the back of PR3, the face of PR2, as well as REFL and AS.

Video 3:   https://www.youtube.com/watch?v=bLHNWHAWZBA is the camera looking at the face of PRM and (through a viewing mirror) BS.

If you watch video 1, you'll see how large the beam gets on the face of PR2.  The main spot, where the straight-through, no-cavity beam is, is a little high of center.  The rest of the inflated beam swirls around that point.

Video 2 shows the same behavior, but you also see that we're much too high on PR3, and too close to the right (as seen on the video) side.

Video 3 is very disconcerting to me.  The main, stationary beam spot seems nicely centered, but the resonant beam, since it inflates and gets big, is very close to the right side of the PRM (as seen on the video). 

It wouldn't surprise me if, were we able to quantify the beam clipping loss on PR3 and PRM, the clipping were the reason we have a crappy PRC gain.  This doesn't explain why we have such a weird inflated beam though.

The instigator of this was that we were seeing ring-ups of ETMs during our ALS locks this evening.  We measured the ETMY violin resonance to be 624.10 Hz, and Rana found an elog saying that the ETMX was around 631 Hz, so we made a 2 notch filter and added it to FM4 of the LSC-SUS filter banks for both ETMs. 

For the ETMY resonance, we measured the frequency in the DARM spectrum, and when we looked at the FINE_PHASE_OUT channels, the resonance was only in the Yarm sensor.  So, we conclude that it is coming from ETMY.

Also in the realm of filter modules, the FM3 boost for CARM, DARM, XARM and YARM was changed from zero crossing to ramp with a 1sec ramp time.

Mech Resonance Wiki

I've updated the wiki by trawling the elog for violin entries. Please keep it up to date so that we can make violin notches.

[Rana, Jenne]

We were meditating a little bit on what may be the story behind the PRM violin filter situation.  We locked the PRMI, and turned on and off the violin filters.  We noticed, very bizarrely, that when the violin filters were ON, the servos would oscillate.  Weird.  Also, probably because the oscillation was causing us to hit the limit we have in the MICH servo, we rung up a 3rd harmonic of one of the violin modes, which was at 1955 Hz. 

We took a transfer function of the PRCL servo, saw that the UGF was 300 Hz, and lowered it to ~180 Hz.  After later investigations, that high-ish UGF probably wasn't a problem.  Anyhow, we then took MICH servo transfer functions, and saw some very weird stuff. 

At frequencies where we had violin filter notches, we were seeing peaks in the transfer function, which came close to touching, or crossed the 0dB line!  We suspect that this may have something to do with the balancing of the drives to the optics, since we have PRCL driving PRM, but MICH driving BS and PRM.  What we did was move the violin filter notches into the LSC model.  There were already SUS filter banks in the LSC model (right side of the LSC screen).  In preparation for the DRMI, I have put the BS violin notches into the BS, PRM and SRM filter banks, as well as the PRM and SRM filters into all 3 banks.  Right now for PRMI, I have the BS and PRM notches (as well as the Vio3 notch) turned on in both BS and PRM.  All of the violin-related filters are turned off in the LSC filter bank inside the SUS models.  When we did this, the servo oscillations no longer are excited when we turn on the notches, and when we take a new transfer function, there are no longer weird peaks at the notch frequencies.  More meditation needs to be done.

Also, for the violin3 filter, Rana noted that at 1955 Hz, after we confirmed that the REFL 55 phase was set correctly (and we're using REFL 55 I&Q for PRMI locking), the I-phase had a response of 0.36, while the Q-phase had a response of 0.20.  I should be able to think about these numbers, and decide if the vio3 is for the BS or the PRM violin mode.

the above series of Bode plots shows the MICH Open Loop Gain as the REFL55 phase is adjusted (PURPLE, ORANGE) with the notches in the SUS and then (RED) as the notches are moved to the LSC and made the same for all optics.

In other news, I have the parts that Jamie ordered to make a new 110 demod board, so that's one of my daytime activities now, so we can have both POP110 and AS110.

  Just to rephrase somewhat:

• We balance the BS & PRM actuators in the LSC Output matrix so that there is no MICH signal going into REFL_I @ 100 Hz.
• REFL Phase is adjusted by driving PRM and minimizing Q/I to within ~1 deg (Q/I ratio of ~2%)
• The REFL_I sensing matrix element is ~50x bigger than REFL_Q (in W/m)
• When we turn ON the violin mode notch in the BS SUS, it changes the MICH drive into a purely PRCL drive at that frequency !!!
• So, putting notches into the SUS screens is bad since it imbalances the drives.

 Ooops, definitely my bad.  I think I was the one who put in the PRM violin filter, so I should have recognized that frequency.  However, I couldn't think of a reason why violin mode filters should be in the LSC filter banks, since we usually put them in C1:SUS-optic_LSC filter banks. 

Anyhow, so that I don't make a mistake like that again, I was looking through all of the violin mode filters for all the optics, so I could write down the frequencies.  The result: confusion.

Violin filters in C1:SUS-optic_LSC filter banks:

The PRM's violin mode filter is set correctly to 627.75Hz:  elog 8533.

One of BS or SRM has probably been measured (presumably BS), since they have the same filters centered around 645Hz. 

Neither ITM has a violin filter.

The ETMs have violin filters in the 440's, which I assume was correct back in the MOS days, before 2010.

Vio2 filters in C1:SUS-optic_LSC filter banks:

PRM, SRM, BS, ITMX, ITMY:  Centered around 1285 Hz, which matches the violin notch frequencies in the BS and SRM.

ETMY:  Centered around 883.5Hz, which matches the old 440Hz frequency

ETMX:  Centered around 631Hz .  So, this could have been measured, but it was put into the wrong filter module.

Koji tells me that we don't really need to worry about all these violin filters unless they are required (as with the PRM and the obnoxious hum a few weeks ago), so I 'm not going to do any measuring / adjusting of these filters for now.

I installed Virtual Box on rossa. Then I put Windows 7 in there and am now installing Altium.

You can run Windows on rossa by just clicking Applications -> System Tools -> Virtual Box.

MC and PMC vis:

MC REFL Unlocked    = 4.4

MC REFL Locked      = 0.67

 1 - Locked/Unlocked = 85%

PMC REFL Unlocked   = 0.270

PMC REFL Locked     = 0.013

 1 - Locked/Unlocked = 95%

I checked (by looking through recent trends) that the zero level is zero on both channels. I tried to do a proper mode scan, but we have lost the PSL fast channels during the upgrade sadly. Also, the DC signal for the PMC REFL needs some gain. Unlocked level should be more like 3-5 V.

Also used the instructions from this page to add Google's sources to rosalba's apt-get list and then installed Chrome.

[Steve, Koji, JC]

Steve Vass came by today and was loaded with information. Here are a couple things we went over:
- Removal of the large optical table.
- Disconnecting the roughing pumps to prevent oil contamination. 
- Plexiglass End Enclosures
- TP1 maintenance Information

Removal of the large optical table. 

    Steve mention to us that there will be 2 machines that have to raise and rotate the optical. The optical table is 2 ft wide when rotated and this seems to easily give us clearance to get this guy out if we set it on piano dollies. The only issue we encountered is that we may have to disconnect the small power supply rack by 1X2 to make room for one of the machines that will rotate the table. If we manage to lift the table, slide it over to a more open area, lift again, and remove the dollies, then this may give us enough space for this machine and we won’t have to disconnect the power supply rack by 1x2. Overall, turning the table over on its side and maneuvering it into the aisle to go down the aisle along Xarm is the trickiest part. From there, we just have to find out where we are going to take this monster of an optical table.

Disconnecting the roughing pumps to prevent oil contamination
    

Disconnecting the roughing pumps to prevent oil contamination. 

    Steve let us know that he would disconnect to oil vacuum pumps after getting to your nominal vacuum pressure. This prevents these pump from possibly feeding oil into the system. Each of these pumps have an intentional leak vale that keeps the pressure above 300 mtorr. If the pressure get any lower, the pumps will begin to back pressure oil into the system.

Plexiglass Enclosures

  

   I asked Steve about some information on the end enclosures and PSL Enclosure. For the end enclosures, these were custom made. The film on the enclosure was added by people who do car window tinting. This film is not as strong as the plexiglass for the PSL Table. I have to look through Steve’s physical documents to find a receipt, or information of where he purchase the custom enclosure. As for the PSL enclosure, the film is actually imbedded/ combined with the plexiglass. This can withstand much more power than the end enclosures.

TP1 Maintenance
    
    Steve has sent TP1 and the controller for maintenance before. It seems like we need to do this roughly ever 4-6 years and the last time TP1 was shipped out for maintenance was in 2018. During this, Steve said he thinks he was shipped a temporary pump to use in the mean time while TP1 was being repaired. When there is an error with the pump, it will pop up on the controller as show in [elog 14189](https://nodus.ligo.caltech.edu:8081/40m/14189)Anyways, it seems like TP1 will have some issues coming up.

I've attempted to visualize the various components of the cost function in the way I've defined it for the current iteration of the Oplev optimal control loop design code. For each term in the cost function, the way the cost is computed depends on the ratio of the abscissa value to some threshold value (set by hand for now) - if this ratio is >1, the cost is the logarithm of the ratio, whereas if the ratio is <1, the cost is the square of the ratio. Continuity is enforced at the point at which this transition happens. I've plotted the cost function for some of the terms entering the code right now - indicated in dashed red lines are the approximate value of each of these costs for our current Oplev loop - the weights were chosen so that each of the costs were O(10) for the current controller, and the idea was that the optimizer could drive these down to hopefully O(1), but I've not yet gotten that to happen.

Based on the meeting yesterday, some possible ideas:

1. For minimizing the control noise injection - we know the transfer function from the Oplev control signal coupling to MICH from measurements, and we also have a model for the seismic noise. So one term could be a weighted integral of (coupling - seismic) - the weight can give more importance to f>30Hz, and even more importance to f>100Hz. Right now, I don't have any suc frequency dependant requirement on the control signal.
2. Try a simpler problem first - pendulum local damping. The position damping controller for example has fewer roots in the complex plane. Although it too has some B/R notches, which account for 16 complex roots, and hence, 32 parameters, so maybe this isn't really a simpler problem?
3. How do we pick the number of excess poles compared to zeros in the overall transfer function? The OL loop low-pass filters are elliptic filters, which achieve the fastest transition between the passband and stopband, but for the Oplev loop roll-off, perhaps its better to have a just have some poles to roll off the HF response?

Viton flouroelastomers have somewhat variable material properties. The following parameters are being used for eigenfrequency analysis.

Young's Modulus: 72,500-87,000 psi (cite: http://www.row-inc.com/pfa.html) *Accurate for PFAs

Poisson's Ratio: 0.48-0.50 (cite: http://www.engineeringtoolbox.com/poissons-ratio-d_1224.html) *Accurate for rubber

Density: 1800 kg/m^3 (cite: http://physics.nist.gov/cgi-bin/Star/compos.pl?matno=275)

 The Young's Modulus for PFA turned out to be orders of magnitude greater than for Viton. The revised values produced much more accurate results:

Young's Modulus for Viton-75: 1950 psi or 6.6 MPa

(Courtesy Row, Inc. and Steve Vass)

This website contains other details: http://www.row-inc.com/viton.html

The IBM laptop at EX was running Ubuntu 14, so I allowed it to start upgrading itself to Ubuntu16 as it desired. After it is done, I will upgrade it to 18.04 LTS. We should have them all run LTS.

I tested the voltage dividers and was getting up to about 3V. I retested the mic w/o the voltage divider in place, and, lo and behold, I was able to generate about 70-75V (previously, I maxed out at 45V). I'm not 100% sure why this was, but it occurs to me that, before, the sounds I was generating were short in duration (loud claps, short yelps). This time, I tried yelling continuously into the microphone. So, probably, I simply wasn't seeing the real peak before on the scope because it was too short to pick up. I have corrected the voltage dividers (by replacing the 25.5 kOhm resistors, which were in parallel with the ADC, with 10 kOhm resistors, taking the voltage ratio to ~60:1) and tested them. I haven't been able to generate more than 1500 mV, so I think they are safe. (It's possible we would have been fine with the old setup, since I think it would be hard to get any noises as loud as I was making, but better safe than sorry, right?)

I'm attaching a diagram of the new-and-improved voltage dividers.