ntp is now installed on all the workstations.  I also added it to the /users/controls/workstation-setup.sh script

As Rolf pointed out when he was here yesterday, all of our IOPs are filled with parts for ADCs and DACs that don't actually exist in the system.  This was causing needless module error messages and IOP GDS screens that were full of red indicators.  All the IOP models were identically stuffed with 9 ADC parts, 8 DAC parts, and 4 BO parts, even though none of the actual front end IO chassis had physical configurations even remotely like that.  This was probably not causing any particular malfunctions, but it's not right nonetheless.

I went through each IOP, c1x0{1-5}, and changed them to reflect the actual physical hardware in those systems.  I have committed these changes to the svn, but I haven't rebuilt the models yet.  I'll need to be able to restart all models to test the changes, so I'm going to wait until we have a quiet time, probably next week.

We are discussing venting first thing next week, with the goal of
diagnosing what's going on in the PRC.

Reminder of the overall vent plan:

https://wiki-40m.ligo.caltech.edu/vent

Since we won't be prepared for tip-tilt installation (item 2), we should
focus most of the effort on diagnosing what's going on in the PRC.  Of
the other planned activities:

(1) dichroic mirror replacement for PR3 and SR3

  Given that we'll be working on the PRC, we might consider going ahead
  with this replacement, especially if the folding mirror becomes
  suspect for whatever reason.  In any case we should have the new
  mirrors ready to install, which means we should get the phase map
  measurements asap.

(3) black glass beam dumps:

  Install as time and manpower permits.  We need to make sure all needed
  components are baked and ready to install.

(4) OSEM mount screws:

  Delay until next vent.

(5) new periscope plate:

  Delay until next vent.

(6) cavity scattering measurement setup

  Delay until next vent.

The "red for FB connection" issue was probably a dead mx_stream on c1lsc.  That can usually be fixed by just restarting mx_stream.

There is definitely a problem with c1oaf, though.  It crashes immediately after attempting to start.  kernel log for a crash included below.

We will leave c1oaf off until we have time to debug.

[83752.505720] c1oaf: Send Computer Number  = 0
[83752.505720] c1oaf: entering the loop
[83752.505720] c1oaf: waiting to sync 19520
[83753.207372] c1oaf: Synched 701492
[83753.207372] general protection fault: 0000 [#2] SMP 
[83753.207372] last sysfs file: /sys/devices/pci0000:00/0000:00:1e.0/0000:2e:01.0/class
[83753.207372] CPU 4 
[83753.207372] Modules linked in: c1oaf c1ass c1sup c1lsp c1cal c1lsc c1x04 open_mx dis_irm dis_dx dis_kosif mbuf [last unloaded: c1oaf]
[83753.207372] 
[83753.207372] Pid: 0, comm: swapper Tainted: G      D    2.6.34.1 #5 X7DWU/X7DWU
[83753.207372] RIP: 0010:[<ffffffffa1bf7567>]  [<ffffffffa1bf7567>] T.2870+0x27/0xbf0 [c1oaf]
[83753.207372] RSP: 0000:ffff88023ecc1aa8  EFLAGS: 00010092
[83753.207372] RAX: ffff88023ecc1af8 RBX: ffff88023ecc1ae8 RCX: ffffffffa1c35e48
[83753.207372] RDX: 0000000000000000 RSI: 0000000000000020 RDI: ffffffffa1c21360
[83753.207372] RBP: ffff88023ecc1bb8 R08: 0000000000000000 R09: 0000000000175f60
[83753.207372] R10: 0000000000000000 R11: ffffffffa1c2a640 R12: ffff88023ecc1b38
[83753.207372] R13: ffffffffa1c2a640 R14: 0000000000007fff R15: 0000000000000000
[83753.207372] FS:  0000000000000000(0000) GS:ffff880001f00000(0000) knlGS:0000000000000000
[83753.207372] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[83753.207372] CR2: 000000000378a040 CR3: 0000000001a09000 CR4: 00000000000406e0
[83753.207372] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[83753.207372] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[83753.207372] Process swapper (pid: 0, threadinfo ffff88023ecc0000, task ffff88023ec7eae0)
[83753.207372] Stack:
[83753.207372]  ffff88023ecc1ab8 0000000000000096 0000000000000019 ffff88023ecc1b18
[83753.207372] <0> 0000000000014729 0000000000032a0c ffff880001e12d90 000000000000000a
[83753.207372] <0> ffff88023ecc1bb8 ffffffffa1c06cad ffff88023ecc1be8 000000000000000f
[83753.207372] Call Trace:
[83753.207372]  [<ffffffffa1c06cad>] ? filterModuleD+0xd6d/0xe40 [c1oaf]
[83753.207372]  [<ffffffffa1c07ae3>] feCode+0xd63/0x129b0 [c1oaf]
[83753.207372]  [<ffffffffa1c00dc6>] ? T.2888+0x1966/0x1f10 [c1oaf]
[83753.207372]  [<ffffffffa1c1b3bf>] fe_start+0x1c8f/0x3060 [c1oaf]
[83753.207372]  [<ffffffff8102ce57>] ? select_task_rq_fair+0x2c8/0x821
[83753.207372]  [<ffffffff8104cd8b>] ? enqueue_hrtimer+0x65/0x72
[83753.207372]  [<ffffffff8104d8f6>] ? __hrtimer_start_range_ns+0x2d6/0x2e8
[83753.207372]  [<ffffffff8104d91b>] ? hrtimer_start+0x13/0x15
[83753.207372]  [<ffffffff810173df>] play_dead_common+0x6e/0x70
[83753.207372]  [<ffffffff810173ea>] native_play_dead+0x9/0x20
[83753.207372]  [<ffffffff81001c38>] cpu_idle+0x46/0x8d
[83753.207372]  [<ffffffff814ec523>] start_secondary+0x192/0x196
[83753.207372] Code: 1f 44 00 00 55 66 0f 57 c0 48 89 e5 41 57 41 56 41 55 41 54 53 48 8d 9d 30 ff ff ff 48 8d 43 10 4c 8d 63 50 48 81 ec e8 00 00 00 <66> 0f 29 85 30 ff ff ff 48 89 85 18 ff ff ff 31 c0 48 8d 53 78 
[83753.207372] RIP  [<ffffffffa1bf7567>] T.2870+0x27/0xbf0 [c1oaf]
[83753.207372]  RSP <ffff88023ecc1aa8>
[83753.207372] ---[ end trace df3ef089d7e64971 ]---
[83753.207372] Kernel panic - not syncing: Attempted to kill the idle task!
[83753.207372] Pid: 0, comm: swapper Tainted: G      D    2.6.34.1 #5
[83753.207372] Call Trace:
[83753.207372]  [<ffffffff814ef6f4>] panic+0x73/0xe8
[83753.207372]  [<ffffffff81063c19>] ? crash_kexec+0xef/0xf9
[83753.207372]  [<ffffffff8103a386>] do_exit+0x6d/0x712
[83753.207372]  [<ffffffff81037311>] ? spin_unlock_irqrestore+0x9/0xb
[83753.207372]  [<ffffffff81037f1b>] ? kmsg_dump+0x115/0x12f
[83753.207372]  [<ffffffff81006583>] oops_end+0xb1/0xb9
[83753.207372]  [<ffffffff8100674e>] die+0x55/0x5e
[83753.207372]  [<ffffffff81004496>] do_general_protection+0x12a/0x132
[83753.207372]  [<ffffffff814f17af>] general_protection+0x1f/0x30
[83753.207372]  [<ffffffffa1bf7567>] ? T.2870+0x27/0xbf0 [c1oaf]
[83753.207372]  [<ffffffffa1c06cad>] ? filterModuleD+0xd6d/0xe40 [c1oaf]
[83753.207372]  [<ffffffffa1c07ae3>] feCode+0xd63/0x129b0 [c1oaf]
[83753.207372]  [<ffffffffa1c00dc6>] ? T.2888+0x1966/0x1f10 [c1oaf]
[83753.207372]  [<ffffffffa1c1b3bf>] fe_start+0x1c8f/0x3060 [c1oaf]
[83753.207372]  [<ffffffff8102ce57>] ? select_task_rq_fair+0x2c8/0x821
[83753.207372]  [<ffffffff8104cd8b>] ? enqueue_hrtimer+0x65/0x72
[83753.207372]  [<ffffffff8104d8f6>] ? __hrtimer_start_range_ns+0x2d6/0x2e8
[83753.207372]  [<ffffffff8104d91b>] ? hrtimer_start+0x13/0x15
[83753.207372]  [<ffffffff810173df>] play_dead_common+0x6e/0x70
[83753.207372]  [<ffffffff810173ea>] native_play_dead+0x9/0x20
[83753.207372]  [<ffffffff81001c38>] cpu_idle+0x46/0x8d
[83753.207372]  [<ffffffff814ec523>] start_secondary+0x192/0x196

In the c1ioo model there were filter modules at the output of the WFS output matrix, right before going to the MC SUS ASCs but right after the dither line inputs, that were not exposed in the C1IOO_WFS_OVERVIEW screen (bad!).  I switched the order of these modules and the dither sums, so these output filters are now before the dither inputs.  This will allow us to turn off all the WFS feedback while still allowing the dither lines.

I updated the medm screens as well (see attached images).

I think we (Jenne, Jamie) are going to leave things for the night to give ourselves more time to prep for the vent tomorrow.

We still need to put in the PSL output beam attenuator, and then redo the MC alignment.

The AS spot is also indicating that we're clipping somewhere (see below).  We need to align things in the vertex and then check the centerings on the AP table.

So I think we're back on track and should be ready to vent by the end of the day tomorrow.

I just spent the last hour checking in a bunch of uncommitted changes to stuff in the SVN.  We need to be MUCH BETTER about this.  We must commit changes after we make them.  When multiple changes get mixed together there's no way to recover from one bad one.

ETMX appears to be fine.  It was stuck to its OSEMs in the usual way.  I touched it and it dislodged and is now swinging freely.  Damping loops have been re-engaged.

 I think we should NOT do any adjustment of IP ANG/POS now.  We should in fact try to recover them when doing the PRM spot centering

The motivation for removing the ITMX door was so that the scatter measurement team could check alignment of the new viewing mirror next to ETMX.  After discussion today we decided that everything can be done at the X end.  They can inject a probe beam into the ETMX chamber, bounce it off of ITMX and align the viewing mirror with the reflection.  So we'll leave ITMX door on for now.

We should, however, inspect the situation ITMY and make sure we have good clearance in the Y arm part of the Michaelson.  Koji previously expressed suspicion that we might have clipping on the southern edge of the POY steering mirror, so we need to check that out.

Koji and I discussed the situation for getting camera face views of BS and PRM.  Koji said the original idea was to see if we could install something at the south-east view port of ITMX chamber.  Steve also suggested utilizing the "ceiling" camera mounted on the top of the IOO chamber.

Vertex tasks:

• check spot centering in PRM
• check that REFL is getting cleanly to the AP table
• check IPPOS and IPANG - we should be adjusting IPPOS or IPANG at this point
• check spot centering on BS
• remove ITMY north door
• check clearance of POY steering mirror
• ...

in parallel:

• Steve will inspect the situation for getting a camera view of BS and PRM face, either through IOO or ITMX.

End X tasks:

• install baffle
• install "permanent" ITMX viewing mirror, on west side of ETMX - this might require moving ETMX SUS cable bracket south
• install temporary steering mirror for probe laser on south-east side of ETMX
• at some point the scatter guys can also do transmission measurements of the ETMX view ports
• ...

I must say that I am not at all happy with the baffle situation.  It is currently completely blocking our camera view of the ETMX face.  Here's a video capture of the ETMX face camera:

The circle is the baffle hole, through which we can see just the bottom edge of the test mass.  I don't think whatever benefit the baffle gives out weights the benefit of being able to see the spot on the mirror.

This afternoon we will try to adjust the baffle, and maybe the camera view mirror, to see if we can get a better shot of the center of the TM.  If we can see the beam spot through the hole we can probably live with it.  If not, I think we should remove the baffle.

We installed beam targets on PRM and BS suspension cages.

On both suspensions one of the screw holes for the target actually houses the set screw for the side OSEM.  This means that the screw on one side of the target only goes in partial way.

The target installed on BS is wrong!  It has a center hole, instead of two 45 deg holes.  I forgot to remove it, but it will obvious it's wrong to the next person who tries to use it.  I believe we're supposed to have a correct target for BS, Steve?

The earthquake stop screws on PRM were too short and were preventing installation of the PRM target.  Therefore, in order to install the target on PRM I had to replace the earthquake stops with ones Jenne and I found in the bake lab clean room that were longer, but have little springs instead of viton inserts at the ends.  This is ok for now, but

WE NEED TO REMEMBER TO REPLACE EARTHQUAKE STOPS ON PRM WHEN WE CLOSE UP.

We checked the beam through PRM and it's a little high to the right (as viewed from behind).  Tomorrow we're going to open ITMX chamber so that we can get a closer look at the spot on PR2.

 I'm very unhappy with the tip-tilts right now.  The amount of hysteresis is ridiculous.  I have no confidence that they will stay pointing wherever we point them.  It's true I poked the top more than it would normally move, but I don't actually believe it wouldn't move in an earthquake.  Given how much hysteresis we're seeing, I expect it will just drift on it's own and we'll loose good pointing again.

And as a reminder, IPPOS/ANG don't help us here before the tip-tilts are in the PRC after the IP pointing sensors.

I think we need to look seriously at possible solutions to eliminate or at least reduce the hysteresis, by either adding weight, or thinner wire, or something.

We really need something better to replace the access connector when we're at air.  This tin foil tunnel crap is dumb.  We can't do any locking in the evening after we've put on the light doors.  We need something that we can put in place of the access connector that allows us access to the OMC and IOO tables, while still allowing IMC locking, and can be left in place at night.

 Can we see the full design?  If we can't lock the mode cleaner with this thing on then it's really of no use.  We want it to be equivalent to the light doors, but allow us to keep the mode cleaner locked.  That's the most important aspect.

 It also needs to be wide enough that the MMT beam can go through, so that we can not only lock the MC, but also work on the rest of the IFO.

I do not remember removing anything from that setup.  We just moved some mirrors and lenses around

For some reason the frame builder and mx stream processes on ALL front ends were down.  I restarted the frame builder and all the mx_stream processes and everything seems to be back to normal.  Unclear what caused this.  The CDS guys are aware of the issue with the mx_stream stability and are working on it.

I made a wiki page for the active IO tip-tilts.  I should have made this a long time ago.

All the front end machines are back up after the outage.  It looks like none of the front end machines came back up once power was restored, and they all needed to be powered manually.  One of the things I want to do in the next CDS upgrade is put all the front end computers in one rack, so we can control their power remotely.

c1sus was the only one that had a little trouble.  It's timing was for some reason not syncing with the frame builder.  Unclear why, but after restarting the models a couple of times things came back.

There's still a little red, but it mostly has to do with the fact that c1oaf is busted and not running (it actually crashes the machine when I tried to start it, so this needs to be fixed!).

All suspension damping has been restored.

For context, there's a is stand-alone cymac test system running at the 40m.  It's not hooked up to anything, except for just being on the martian network (it's not currently mounting any 40m CDS filesystems, for instance).  The machine is temporarily between the 1Y4 and 1Y5 racks.

What are "LID" sensors?  Do you mean the OSEM shadow sensors?  I'm pretty sure that's what you meant, but I'm curious what "LID" means.

I have added some control logic and appropriate output DAC channels for the input tip-tilts (TT1 and TT2) to the c1ass model.

The plan is for all the tip-tilt drive electronics to live in a Eurocrate in 1Y2.  They will then interface with a DAC in c1lsc.

c1ass runs on the c1lsc front-end machine, and therefore seemed like an appropriate place for the control logic to go.

I added and interface to DAC0, and a top_named IOO block, to c1ass:

The IOO block includes two TT_CONTROL library parts, one for each of TT1 and TT2:

This is just a start so that I can start testing the DAC output.

I have not recompiled c1ass yet.  I will do that tomorrow.

I finally got around to rebuilding, installing, and restarting all the IOP models.  Everything went smoothly.  I had to restart all the models on all the screens, but everything seemed to come back up fine.  We now have many fewer dmesg error messages, and the GDS_TP screens are cleaner and don't have a bunch of needless red.

A frame builder restart was also required, due to name changes in unused (but unfortunately still needed) channels in the IOP.

I rebuilt/install/restarted c1ass.  It came up with no problems.  It's now showing DAC0 with no errors.

After lunch I'll test the outputs.

Steve and I managed to access the fuse in the vacuum VME crate, but replacing it did not bring it back up.  We decided to replace the entire crate.

We manually checked that the most important valves, VC1, VM1 and V1, were all closed.  We disconnected their power so that they would automatically close, and we wouldn't have to worry about them accidentally opening when we rebooted the system.

We noted where all the cables were, disconnected everything, and removed the crate.  We noted that one of the values switched when we disconnected one of the IPC cables from a VME card.  We'll note which one it was in a followup post.  We thought that was a little strange, since the VME crate was completely unpowered.

Anyway, we removed the crate, swapped in a spare, replaced all the cards and connections, double checked everything, then powered up the crate.  That's when minor chaos ensued.

When the system came back online after about 20 seconds, we heard a whole bunch of valves switching.  Luckily we were able to get the medm screens back up so that we could see what was going on.

Apparently all of the ION pump valves (VIPEE, VIPEV, VIPSV, VIPSE) opened, which vented the main volume up to 62 mTorr.  All of the annulus valves (VAVSE, VAVSV, VAVBS, VAVEV, VAVEE) also appeared to be open.  One of the roughing pumps was also turned on.  Other stuff we didn't notice?  Bad.

We ran around and manually unplugged all of the ION pump valves, since I couldn't immediately pull up the vacuum control screen.  Once that was done and we could see that the main volume was closed off we went back to figure out what was going on.

We got the medm vacuum control screen back (/cvs/cds/caltech/medm/c0/ve/VacControl_BAK.adl.  really??)  There was a lot of inconsistency between the readback states of the valves and the switch settings.  Toggling the switches seemed to bring things back in line.  At this point it seemed that we had control of the system again.  The epics readings were consistent with what we were seeing in the vacuum rack.

We went through and closed everything that should have been closed.  The line pressure between the big turbo pump TP1 and the rest of the pumps was up at atmosphere, 700 Torr.  We connected the roughing pumps and pumped down the lines so that we could turn the turbos back on.  Once TP2 and TP3 were up to speed, we turned on TP1 and opened V1 to start pumping the main volume back town.   The main volume is at 7e-4 Torr right now.

So there are a couple of problems with the vacuum system.

• Why the hell did valves open when we rebooted the VME crate?  That's very bad.  That should never happen.  If the system is set to come up to an unsafe state that needs to be fixed ASAP.  The ION pump valves should never have opened.  Nor the annulus valves.
• Why were the switches and the readbacks showing different states?
• Apparently there is no control of the turbo pumps through MEDM.  This should be fixed.

I connect belledona, the laptop at the vacuum station to the wired network, so that it's connection would be less flaky.

The tip-tile SOS dewhite/AI boards are now connected to the digital system.

I put together a chassis for one of our space DAC -> IDC interface boards (maybe our last?).  A new SCSI cable now runs from DAC0 in the c1lsc IO chassis in 1Y3, to the DAC interface chassis in 1Y2.

Two homemade ribbon cables go directly from the IDC outputs of the interface chassis to the 66 pin connectors on the backplane of the Eurocrate.  They do not go through the cross-connects, cause cross-connects are stupid.  They go to directly to the lower connectors for slots 1 and 3, which are the slots for the SOS DW/AI boards.  I had to custom make these cables, or course, and it was only slightly tricky to get the correct pins to line up.  I should probably document the cable pin outs.

• cable 0:  IDC0 on interface chassis (DAC channels 0-7) ---> Eurocrate slot 0 (TT1/TT2)
• cable 1:  IDC1 on interface chassis (DAC channels 8-15)---> Eurocrate slot 2 (TT3/TT4)

As reported in a previous log in this thread, I added control logic to the c1ass front-end model for the tip-tilts.  I extended it to include TT_CONTROL (model part) for TT3 and TT4 as well, so we're now using all channels of DAC0 in c1lsc for TT control.

I tested all channels by stepping through values in EPICS and reading the monitor and SMA outputs of the DW/AI boards.  The channels all line up correctly.  A full 32k count output of a DAC channel results in 10V output of the DW/AI boards.  All channels checked out, with a full +-10V swing on their output with a full +-32k count swing of the DAC outputs.

   We're using SN 1 and 2 of the SOS DW/AI boards (seriously!)

The output channels look ok, and not too noisy.

Tomorrow I'll get new SMA cables to connect the DW/AI outputs to the coil driver boards, and I'll start testing the coil driver outputs.

As a reminder:  https://wiki-40m.ligo.caltech.edu/Suspensions/Tip_Tilts_IO

I was working around 1Y2 and 1Y3 when I wired the DAC in the c1lsc IO chassis in 1Y3 to the tip-tilt electronics in 1Y2.  I had to mess around in the back of 1Y3 to get it connected.  I obviously did not intend to touch anything else, but it's certainly possible that I did.

We removed all the folding mirrors ({P,S}R{2,3}) from the IFO and took them into the bake lab clean room.  The idea was that at the very least we would install the new dichroic mirrors, and then maybe replace the suspension wires with thinner ones.

I went in to spend some quality time with one of the tip-tilts.  I got the oplev setup working to characterize the pointing.

I grabbed tip-tilt SN003, which was at PR2.  When I set it up it  was already pointing down by a couple cm over about a meter, which is worse than what we were seeing when it was installed.  I assume it got jostled during transport to the clean room?

I removed the optic that was in there and tried installing one of the dichroics.  It was essentially not possible to remove the optic without bending the wires by quite a bit (~45 degrees).  I decided to remove the whole suspension system (top clamps and mirror assembly) so that I could lay it flat on the table to swap the optic.

I was able to put in the dichroic without much trouble and get the suspension assembly back on to the frame.  I adjusted the clamp at the mirror mount to get it hanging back vertical again.  I was able to get it more-or-less vertical without too much trouble.

I poked at the mirror mount a bit to see how I could affect the hysteresis.  The answer is quite a bit, and stochastically.  Some times I would man-handle it and it wouldn't move at all.  Sometimes I would poke it just a bit and it would move by something like a radian.

A couple of other things I noted:

• The eddy current damping blocks are not at all suspended.  The wires are way too think, so they're basically flexures.  They were all pretty cocked, so I repositioned them by just pushing on them so they were all aligned and centered on the mirror mount magnets.
• The mirror mounts are very clearly purposely made to be light.  All mass that could be milled out has been.  This is very confusing to me, since this is basically the entire problem.  Why were they designed to be so light?  What problem was that supposed to solve?

I also investigated the weights that Steve baked.  These won't work at all.  The gap between the bottom of the mirror mount and the base is too small.  Even the smalled "weights" would hit the base.  So that whole solution is a no-go.

What else can we do?

At this point not much.  We're not going to be able to install more masses without re-engineering things, which is going to take too much time.  We could install thinner wires.  The wires that are being used now are all 0.0036", and we could install 0.0017" wires.  The problem is that we would have to mill down the clamps in order to reuse them, which would be time consuming.

The plan

So at this point I say we just install the dichroics, get them nicely suspended, and then VERY CAREFULLY reinstall them.  We have to be careful we don't jostle them too much when we transport them back to the IFO.  They look like they were too jostled when they were transported to the clean room.

My big question right now is: is the plan to install new dichroics in PR2 and SR2 as well, or just in PR3 and SR3, where the green beams are extracted?  I think the answer is no, we only want to install new dichroics in {P,S}R3.

The future

If we're going to stick with these passive tip-tilts, I think we need to consider machining completely new mirror mounts, that are not designed to be so light.  I think that's basically the only way we're going to solve the hysteresis problem.

I also note that the new active tip-tilts that we're going to use for the IO steering mirrors are going to have all the same problems.  The frame is taller, so the suspensions are longer, but everything else, including the mirror mounts are exactly the same.  I can't see that they're not going to suffer the same issues.  Luckily we'll be able to point them so I guess we won't notice.

When installing the dichroics we need to pay attention to the wedge angle.  I didn't, so the ghost beam is currently point up and to the right (when facing the optic).  We should think carefully about where we want the ghost beams to go.

I also was using TT SN003, which I believe was being used for PR2.  However, I don't think we want to install dichroics in the PR2, and we might want to put all the tip-tilts back in the same spots they were in before.  We therefore may want to put the old optic back in SN003, and put the dichroics in SN005 (PR3) and SN001 (SR3) (see 7601).

jamie, nic, jenne, den, raji, manasa

We were doing pretty well with alignment, until I apparently fucked things up.

We were approaching the arm alignment on two fronts, looking for retro-reflection from both the ITMs and the ETMs.

Nic and Raji were looking for the reflected beam off of ETMY, at the ETMY chamber.  We put an AWG sine excitation into ETMY pitch and yaw.  Nic eventually found the reflected beam, and they adjusted ETMY for retro-reflection.

Meanwhile, Jenne and I adjusted ITMY to get the MICH Y arm beam retro-reflecting to BS.

Jenne and I then moved to the X arm.  We adjusted BS to center on ITMX, then we moved to ETMX to center the beam there.  We didn't both looking for the ETMX reflected beam.  We then went back to BS and adjusted ITMX to get the MICH X arm beam retro-reflected to the BS.

At this point we were fairly confident that we had the PRC, MICH, and X and Y arm alignment ok.

We then moved on the signal recycling cavity.  Having removed and reinstalled the SRC tip-tilts, and realigning everything else, they were not in the correct spot.  The beam was off-center in yaw on SR3, and the SR3 reflected beam was hitting low and to the right on SR2.  I went to loosen SR3 so that I could adjust it's position and yaw, and that when things went wrong.

Apparently I hit something BS table and completely lost the input pointing.  I was completely perplexed until I found that the PZT2 mount looked strange.  The upper adjustment screw appeared to have no range.  Looking closer I realized that we somehow lost the gimble ball between the screw and the mount.  Apparently I somehow hit PZT2 hard enough to separate from the mirror mount from the frame which caused the gimble ball to drop out.  The gimble ball probably got lost in a table hole, so we found a similar mount from which we stole a replacement ball.

However, after putting PZT2 back together things didn't come back to the right place.  We were somehow high going through PRM, so we couldn't retro-reflect from ITMY without completely clipping on the PRM/BS apertures.  wtf.

Jenne looked at some trends and we saw a big jump in the BS/PRM osems.  Clearly I must have hit the table/PZT2 pretty hard, enough to actually kick the table.  I'm completely perplexed how I could have hit it so hard and not really realized it.

Anyway, we stopped at this point, to keep me from punching a hole in the wall.  We will re-asses the situation in the morning.  Hopefully the BS table will have relaxed back to it's original position by then.

 what's going on with those jumps on MC1?  It's smaller, but noticeable, and looks like around the same time.    Did the MC table jump as well?

more looking tomorrow.

The coating should have very low 1064nm p transmission at 45 degrees, which the plot seems to indicate that it does.  That's really the only part of the spec that this measurement is saying anything about.    What makes you say it's out of spec?

Ok, yes, sorry, the data itself does indicate that the transmission is way too high at 45 degrees for 1064 p.

Here's a plot of the BS, PRM, and MC1 suspension shadow sensor trends over the last 24 hours.  I tried to put everything on the same Y scale:

There definitely was some shift in the BS table that is visible in the BS and PRM that seems to be settling back now.  The MC1 is there for reference to show that it didn't really move.

Jamie, Jenne, Nic, Manasa, Raji, Ayaka, Den

We basically walked through the entire alignment again, starting from the Faraday.  We weren't that far off, so we didn't have to do anything too major.  Here's basically the procedure we used:

• Using PZT 1 and 2 we directed the beam through the PRM aperture and through an aperture in front of PR2.  We also got good retro-reflection from PRM (with PRM free-hanging).  This completely determined our input pointing, and once it was done we DID NOT TOUCH the PZT mirrors any more.
• The beam was fortunately still centered on PR2, so we didn't touch PR2.
• Using PR3 we direct the beam through the BS aperture, through the ITMY aperture, and to the ETMY aperture.  This was accomplished by loosening PR3 and twisting it to adjust yaw, moving it forward/backwards to adjust the beam translation, and tapping the mirror mount to affect the hysteresis to adjust pitch.  Surprisingly this worked, and we were able to get the beam cleanly through the BS and Y arm apertures.  Reclamped PR3.
• Adjusted ITMY biases (MEDM) to get Michelson Y arm retro-reflecting to BS.
• Adjusting BS biases (MEDM) we directed the beam through the ITMX and ETMX apertures.
• Adjusted ITMX biases (MEDM) to get Michelson X arm retro-reflecting to BS.

At this point things were looking good and we had Michelson fringes at AS.  Time to align SRC.  This is where things went awry yesterday.  Proceeded more carefully this time:

• Loosened SR3 to adjust yaw pointing towards SRM.  We were pretty far off at SRM, but we could get mostly there with just a little bit of adjustment of SR3.  Got beam centered in yaw on SR2.
• Loosened and adjusted SR2 to get beam centered in yaw on SRM.
• Once we were centered on SR3, SR2, and SRM reclamped SR2/SR3.
• Pitch adjustment was the same stupid stupid jabbing at SR2/3 to get the hysteresis to stick at an acceptable place.**
• Looked at retro-reflection from SRM.  We were off in yaw.  We decided to adjust SRM pointing, rather than go through some painful SR2/3 iterative adjustment.  So unclamped SRM and adjusted him slightly in yaw to get the retro-reflection at BS.

At this point we felt good that we had the full IFO aligned.  We were then able to fairly quickly get the AS beam back out on the AS table.

We took at stab at getting the REFL beam situation figured out.  We confirmed that what we thought was REFL is indeed NOT REFL, although we're still not quite sure what we're seeing.  Since it was getting late we decided to close up and take a stab at it tomorrow, possibly after removing the access connector.

The main tasks for tomorrow:

• Find ALL pick-off beams (POX, POY, POP) and get them out of the vacuum.  We'll use Jenne's new Suresh's old green laser pointer method to deal with POP.
• Find all OPLEV beams and make sure they're all still centered on their optics and are coming out cleanly.
• Center IPPOS and IPANG
• Find REFL and get it cleanly out.
• Do a full check of everything else to make sure there is no clipping and that everything is where we expect it to be.

Then we'll be ready to close.  I don't see us putting on heavy doors tomorrow, but we should be able to get everything mostly done so that we're ready on Monday.

** Comment: I continue to have no confidence that we're going to maintain good pointing with these crappy tip-tilt folding mirrors.

Link to the new 40m DCC Document Tree: E1200979

AS:

REFL:

I think we will still need two active steering mirrors for input pointing into the OMC, after the SRC, so I think we'll still need two of the active TTs there.

My thought was about using the two active TTs that we were going to use as the input PZT replacements to instead replace the PR2/3 suspensions.  Hysteresis in PR2/3 wouldn't be an issue if we could control them.

With static input pointing, ie. leaving PZT2/3 as they are, I think we could use PRM and PR2/3 to compensate for most input pointing drift.  We might have to deal with the beam in PRC not being centered on PRM, though.

Koji's suggestion was that we could replace the PZTs with pico-motors.  This would give us all the DC input pointing control we need.

So I guess the suggestion on the table is to replace PZT1/2 with pico-motor mounts, and then replace PR2/3 with two of the active tip-tilts.  No hysteresis in the PRC, while maintaining full input pointing control.

After a brief look this morning, I called it and declared that we were ok to close up.  The access connector is almost all buttoned up, and both ETM doors are on.

Basically nothing moved since last night, which is good.  Jenne and I were a little bit worried about how the input pointing might have been effected by our moving of the green periscope in the MC chamber.

First thing this morning I went into the BS chamber to check out the alignment situation there.  I put the targets on the PRM and BS cages.  We were basically clear through the PRM aperture, and in retro-reflection.

The BS was not quite so clear.  There is a little bit of clipping through the exit aperture on the X arm side.  However, it didn't seem to me like it was enough to warrant retouching all the input alignment again, as that would have set us back another couple of days at least.

Both arm green beams are cleaning coming out, and are nicely overlapping with the IR beams at the BS (we even have a clean ~04 mode from the Y arm).  The AS and REFL spots look good.  IPANG and IPPOS are centered and haven't moved much since last night.  We're ready to go.

The rest of the vertex doors will go on after lunch.

 After some system updates this evening, firefox can no longer handle the html input encoding for the elog.  I'm not sure what happened.  You can still use the "ELCode" or "plain" input encodings, but "HTML" won't work.  The problem seems to be firefox 17.  ottavia and rosalba were upgraded, while rossa and pianosa have not yet been.

I've installed chromium-browser (debranded chrome) on all the machines as a backup.  Hopefully the problem will clear itself up with the next update.  In the mean time I'll try to figure out what happened.

To use chromium: Appliations -> Internet -> Chromium

I grabbed the a plot of the iLIGO PSL frequency noise spectrum from the Rana manifesto:

Rana's contention is that this spectrum (red trace) is roughly the same as for our NPRO.

From the jenne/mevans/pepper/rana paper Active noise cancellation in a suspended interferometer I pulled a plot of the calibrated MC_L noise spectrum:

The green line on this plot is a rough estimate of where the above laser frequency noise would fall on this plot.  The conversion is:

    L / f  =  10 m / 2.8e14 Hz = 3.5e-14 m/Hz

which at 10 Hz is roughly 1.5e-11 m.  This puts the crossover somewhere between 1 and 10 Hz.

Koji and I figured out what the problem is.  Apparently firefox 17.0 (specifically it's user-agent string) breaks fckeditor, which is the javascript toolbox the elog uses for the wysiwyg text editor.  See https://support.mozilla.org/en-US/questions/942438.

The suspect line was in elog/fckeditor/editor/js/fckeditorcode_gecko.js.  I hacked it up so that it stopped whatever crappy conditional user agent crap it was doing.  It seems to be working now.

Edit by Koji: In order to make this change work, I needed to clear the cache of firefox from Tool/Clear Recent History menu.

I've installed the new nds2 packages on the control room machines.

These new packages include some new and improved interfaces for python, matlab, and octave that were not previously available. See the documentation in:

  /usr/share/doc/nds2-client-doc/html/index.html

for details on how to use them.  They all work something like:

  conn = nds2.connection('fb', 8088)
  chans = conn.findChannels()
  buffers = conn.fetch(t1, t2, {c1,...})
  data = buffers(1).getData()

NOTE: the new interface for python is distinct from the one provided by pynds.  The old pynds interface should continue to work, though.

To use the new matlab interface, you have to first issue the following command:

   javaaddpath('/usr/lib/java')

I'll try to figure out a way to have that included automatically.

The old Matlab mex functions (NDS*_GetData, NDS*_GetChannel, etc.) are now provided by a new and improved package.  Those should now work "out of the box".

The NDS2 protocol is not for non-DQ, but the NDS2 client is capable of talking both the NDS1 and NDS2 protocols.

fb:8088 is an NDS1 server, so the client is talking NDS1 to fb.  It should therefore be capable of getting online data.

It doesn't seem to be seeing the online channels, though, so I'll work with Leo to figure out what's going on there.

The old mex functions, which like I said are now available, aren't capable of getting online data.

Leo fixed an issue with the new nds2-client packages that was preventing it from retrieving online data.  It's working now from matlab, python, and octave.

Here's an example of a dataviewer-like script in python:

#!/usr/bin/python

import sys
import nds2
from pylab import *

# channels are command line arguments
channels = sys.argv[1:]

conn = nds2.connection('fb', 8088)

fig = figure()
fig.show()
for bufs in conn.iterate(channels):
    fig.clf()
    for buf in bufs:
        plot(buf.data)
    draw()

Everything was fine.  Apparently these guys just forgot that the cable from the rack to the chamber flips it's pins.  There was also a small problem with the patch cable from the coil driver that had flipped pins.  This was fixed.  The coil driver signals are now getting to the TTs.

Investigating why the pitch/yaw seems to be flipped...

[Jamie, Manasa, Jenne]

We started by verifying that the tip-tilts were getting the correct signals at the correct coils, and were hanging properly without touching.

We started with TT2.  It was not hanging freely.  One of the coils was in much further than the others, and the mirror frame was basically sitting on the back side yaw dampers.  I backed out the coil to match the others, and backed off all of the dampers, both in back and the corner dampers on the front.

Once the mirror was freely suspended, we borrowed the BS oplev to verify that the mirror was hanging vertically.  I adjusted the adjustment screw on the bottom of the frame to make it level.  Once that was done, we verified our EPICS control.  We finally figured out that some of the coils have polarity flipped relative to the others, which is why we were seeing pitch as yaw and vice-versa.  At that point we were satisfied with how TT2 was hanging, and went back to TT1.

Given how hard it is to look at TT1, I just made sure all the dampers were backed out and touched the mirror frame to verify that it was freely swinging.  I leveled TT1 with the lower frame adjustment screw by looking at the spot position on MMT1.  Once it was level, we adjusted the EPICS biases in yaw to get it centered in yaw on MMT1.

I then adjusted the screws on MMT1 to get the beam centered at MMT2, and did the same at MMT2 to get the beam centered vertically at TT2.

I put the target at PRM and the double target at BS.  I loosened TT2 from it's base so that I could push it around a bit.  Once I had it in a reasonable position, with a beam coming out at PR3, I adjusted MMT1 to get the beam centered through the PRM target.  I went back and checked that we were still centered at MMT1.  We then adjusted the pitch and yaw of TT2 to get the transmitted beam through the BS targets as clear as possible.

At this point we stopped and closed up.  Tomorrow first thing AM we'll get our beams at the ETMs, try to finalize the input alignment, and see if we can do some in-air locking.

The plan is still to close up at the end of the week.

[jenne, jamie]

Jenne and I got the half PRC flashing.  We could see flashes in the PRM and PR2 face cameras.

We took out the mirror in the REFL path on the AP that diverts the beam to the REFL RF pds so that we could get more light on the REFL camera.  Added an ND filter to the REFL camera so as not to saturate.

[Koji, Jamie]

We tweaked up the alignment of the half PRC a bit.  Koji started by looking at the REFL and POP DC powers as a function of TT2 and PRM alignment. 
He found that the reflected beam for good PRC transmission was not well overlapped at REFL.  When the beam was well overlapped at REFL, there was clipping in the REFL path on the AS table.

We started by getting good overlap at REFL, and then went to the AS table to tweak up all the beams on the REFL pds and cameras.
This made the unlocked REFL DC about 40 count. This was about 10mV (=0.2mA) at the REFL55 PD.
This amazed Koji since we found the REFL DC (of the day) of 160 as the maximum of the day for a particular combination of the PRM Pitch and TT2 Pitch. So something wrong could be somewhere.

We then moved to the ITMX table where we cleaned up the POP path.  We noticed that the lens in the POP path is a little slow, so the beam is too big on the POP PD and on the POP camera (and on the camera pick-off mirror as well). 
We moved the currently unused POP55 and POP22/110 RFPDs out of the way so we could move the POP RF PD and camera back closer to the focus.  Things are better, but we still need to get a better focus, particularly on the POP PD.

We found two irides on the oplev path. They are too big and one of these is too close to the POP beam. Since it does not make sense too to have two irides in vicinity, we pulled out that one from the post.

Other things we noticed:

• The POP beam is definitely clipping in the vacuum, looks like on two sides.
• We can probably get better layout on the POP table, so we're not hitting mirrors at oblique angles and can get beams on grid paths.

After the alignment work on the tables, we started locking the cavity. We already saw the improvement of the POPDC power from 1000 cnt to 2500 cnt without any realignment.
Once PRM is tweaked a little (0.01ish for pitch and yaw), the maximum POPDC of 6000 was achieved. But still the POP camera shows non-gaussian shape of the beam and the Faraday camera shows bright
scattering of the beam. It seems that the scattering at the Faraday is not from the main beam but the halo leaking from the cavity (i.e. unlocking of the cavity made the scattering disappeared)

Tomorrow Jenne and I will go into BS to tweak the alignment of the TEMP PRC flat mirror, and into ITMX to see if we can clean up the POP path.