Times in PST

08:33 Bubba to CER changing filters

08:37 Peter to H2 PSL enclosure

10:22 Corey to squeezer bay, Kyle checking vacuum gauges in LVEA

10:35 Kyle out of LVEA

11:05 Doug to Mid X

11:12 Corey out

11:41 Peter out

12:35 Corey to LVEA for a cable

12:40 Corey out

13:57 Peter and Ed to H2 PSL enclosure

15:31 Peter and Ed out

15:45 Kyle in LVEA shutting off pumps

15:52 Kyle out

Short version: we think CPS's are limiting st2 performance above 10hz. We have modfication ready to try that we think will be quick and painless to try that can be easily backed out.

So after sorting out configuration issues with the end stations, Jeff and I (mostly Jeff) have come up with a small modification to try on the St2 BSC 250mhz blends. We noticed on my BSC performance plots from the the other day that turning on the St2 loops reduced the St2 performance at high frequency. We think this is because the CPS isn't rolled off fast enough in the blend filter, so we messed around with a couple ideas in foton, see attachment. The current blend is shown in red The first idea was a simple pole a 5hz, blue on the plot. This rolled the CPS off quickly, but lost phase around the blend frequency. Next we tried a couple pairs of poles at 10zh, which improved things some, losing less phase at <1hz, but introduced some gain peaking at 10hz (green and brown traces). Finally we used a low-q elliptical filter and it was just right. Or less bad. The combined fitler is shown in cyan(?), the ellipse only is shown in black.

In foton the zpk of the ellipse is : zpk([17.782+i*26.674;17.782-i*26.674],[5.148+i*9.424;5.148-i*9.424],1,"n"). The filter isn't loaded yet, it's not  being used, but first thing Monday morning, I hope install and test it for each dof on st2.

Scott L. Ed P. Chris S.

The cleaning results for the past week are posted here. The crew was able to clean to the single door between X-1-5 and X-1-6 double doors. The crevice cleaning remains to be completed in this section. The crew only worked a half day today because of dentist and other appointments.
Continuous monitoring of beam tube pressures by the control room operator during cleaning operations. 

The gnuradio package has been installed on Ubuntu control room workstations to support the cdsutils waterfall plotter.

Chris, Stefan

Tonight we did a full alignment starting with the Green WFS and we tested the interplay of Green WFS to ETM during DRMI lock acquisition. The Green WFS loop as expected dues a great job at keeping the green arm power from drifting, even when the tidal is on. 

However we were hampered with a new issue: a growing oscillation in the IM4 loop that eventually broke the lock. Not sure why it is that different tonight. There are a couple of lock losses on record that can be looked at tomorrow.

The terminator package has been installed on the Ubuntu workstations, including opslogin. This package is particularly useful if you are logging in remotely using X forwarding, as it presents a terminal window that can be split vertically and horizontally multiple times, with a new shell in each window.  Execute "terminator" at the command line, use the right mouse button to split the display.

The terminator terminal package has been installed on x1work.  This would be particularly useful when logging in remotely (with X forwarding), as you can enter the command "terminator" and you'll get a terminal window that can be split vertically and horizontally multiple times (using the right mouse button), giving you a new terminal window each time.

With JeffK's adjustment of the HEPI ITMX last night and this morning's update, all the LHO SEI SDFs are zero'd.

After Jeff's HEPI ITMX change yesterday, all that remained was the changes (corrections) to the ETM ISI ST2 Z & RZ Blends that Jim did yesterday.  I updated the SDF & committed all files to the SVN this morning.

Similar to my BSC data from a couple days ago, except probably more correct.

Nutsinee, Aidan, Elli

Today we worked on getting the end station HWS working. 

We started at EY.  Made adjustments to the HWS beam path on ISCTEY.  We changed HWS-M1 and HWS-3 alignment so that the weaker reflected beam from these optics goes to the HWS.  We dumped the stronger beams.  We were able to take an image using the take command, run stream_image_EY and Run_HWS_ETMY codes.  Attached are HWS images with and without the HWS plate, after our changes to the alignment.

At EX, the beam on ISCTEX  going to the HWS path was to high, so after talking to Sheila, we moved the BS that picks of the HWS path (HWS-BS1) down in pitch to level of the HWS beam path.  We watched the H1:ALS-X_QPDs and the beam position moved up a little bit but was still roughly centered on the QPDs.  We chose the strong reflection from BS1 and the weaker reflection from BS2 (if the HWS is saturating we can use the weaker reflection from BS1).  HWS-M5 also drops the beam intensity.  We then moved HWS-M1 and HWS-BS2 to center the beam on the HWS.  We confirmed take command, stream_image_EX and Run_HWS_ETMX work.  The beam on HWSEX is not as clean as on HWSEY.  The beam is not clipping on any of the HWS optics, but looks like it may be clipping somewhere further upstream of HWS-BS1.  Attached is a photo of the beam before it hits HWS-M1.

Sheila, Stefan, Chris, 

Today we did several things that should make operating the IFO a littel easier, both for commisioners and operators.  Stefan rearranged the feedback topology of the green wfs, so that ETMs get the signal from DOF1 (which is a WFS signal) (output matrix shown in screen shot).  Previously we had the ETMs getting only the camera signal, so the other WFS needed to be on to use this loop.  This is better because we believe the ETMs drift more than the ITMs, and we want to avoid moving the ITMs between locklosses so that we don't mess up the corner alingment.  This is now implemented as the states which have ETM WFS in the ALS arm guardians, and the ISC_LOCK guardian requests these states.  This prevents the constant need for commisioners to touch up ETM alingments after locklosses.  The guardian should turn these WFS off before the 

Chris also wrote a new wfs offload functio today, which is in ISC_library and called smooth offload.  Its used in the ISC_DOF now, but there shouldn't be much of a change in the procedure for users due to these changes.  I moved the integrators for the INP1 +INP2 loops into the suspensions ( IM4 was missing one) so that this will work.  I've also deleted some of that states that we no longer use from this guardian to reduce confusion a little bit. I've also added a a state in the ALS ARM guardians that offloads the WFS using this function, this works and can be used durring the inital alingment sequence.  

This smooth_offload will help us to offload the DRMi WFS as well, but I haven't tested this yet.  I commited the guardians before starting these changes.

Hopefully tomorow we will make a few more changes to make it easier for operators to do inital alingment, so stay tuned for some updated instructions.  For now the main change is that we can offlaod green wfs using the ALS arm guardians. 

J. Kissel, S. Dwyer

Sheila had discovered that the ISC inputs to the SRM and PRM suspensions had been turned off via a zeroed gain. It's unclear which guardian has, or does, or what person has or does, change these inputs, but we don't *want* then to change, and we want them to be 1.0, so therefore we want them monitored. 

I've hand edited the SDF file for H1 SUS SRM and H1 SUS PRM, i.e.
${userapps}/release/sus/h1/burtfiles/h1susprm_safe.snap
${userapps}/release/sus/h1/burtfiles/h1sussrm_safe.snap
to replace the 0 with a 1 on the last column of the following channels
H1:SUS-PRM_M3_ISCINF_L_GAIN
H1:SUS-PRM_M3_ISCINF_L_TRAMP
H1:SUS-PRM_M3_ISCINF_P_GAIN
H1:SUS-PRM_M3_ISCINF_P_TRAMP
H1:SUS-PRM_M3_ISCINF_Y_GAIN
H1:SUS-PRM_M3_ISCINF_Y_TRAMP
and I've changed the desired value of the gain to be 1.0. I then went to each suspension's SDF overview screen, which indicated a modified SDF file as expected, and I hit LOAD TABLE ONLY. Voila! Channels moved from the "NOT MON" list to the "DIFF" list, and then disappeared from the "DIFF" list.

I've committed the two new SDFs to the userapps repo.

As the SDF becomes more user-friendly, which should omce with an RCG upgrade, and Guardians vs. SDF systems get more use, we will hopefully widdle down to a final set of channels that are monitored, and a final set of channels that are controlled by Guardian.

J. Kissel, J. Rollins

Summary: I've zeroed out the RX to Z element of the IPSALIGN matrix for H1 HPI ITMX, because it's SDF system was showing it containing a small, non-zero value -- different front the expected value of zero. This coefficient was small to begin with, and never proven to be effective. See details below.

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

Jamie pointed me to the last SEI SDF system that was reporting differences in its table: H1 HPI ITMX. The single difference was in H1:HPI-ITMX_IPSALIGN_6_5, which is the RX to Z element of the IPSALIGN matrix, used to decouple RX tilt from Z drive. It had a current value of -0.0013 and a SDF table value of 0.000.

Hugh's aLOG on the derivation of this specific coefficient (see LHO aLOG 16118) is wishy-washy [edited for brevity]: 
"[W]ith the [RX to Z] correction factor of +0.0013 installed, [the] HEPI Z to ISI tilt was [...] looking pretty consistently wrong [...] so I switched the sign and [...] it looks as equally bad.
[...]
This leads me to the conclusion that [...] the plant condition/measurement setup is [inconsistent] at these [small] coupling levels. [...] The next step is to remove the coupling factor and remeasure this Z to RX and see if it is similar.
[...]
The likely course will be that we don't care about the coupling at this level and leave them unpopulated for now."

But I found no further follow-up aLOG of whether Hugh assessed the performance without the element installed. A dataviewer trend reveals the value had been -0.0013 *since* Jan 16th 2015 (when he wrote the above quoted log). However, the SDF system for HPI ITMX -- which according to the date of the log that Hugh posted when he turned all of the HEPI's SDF systems ON (16217) -- didn't exist until Jan 22nd, so I don't understand why the table suggests it should be 0.0. Maybe Hugh was leaving the coefficient installed, but different from the SDF table to remind himself that this was still to be investigated? Dunno.

Anyways -- I've zeroed the element, as the SDF system wanted, and there are no longer any diffs. If the coupling is as small as the measurement / calculation suggests, then it should have negligible impact on the SEI system's performance.

Aidan, Jamie

We now have two TCS guardian nodes: TCS_ITMY and TCS_ITMX.

These are preliminary and contain only diagnostics and no automation.  They are checking the status of the main CO2 lasers on ITMX and ITMY.

I added links to them in the empty space in the middle of the GUARD_OVERVIEW screen:

They are both running identical code from a common library:

USERAPPS/tcs/common/guardian/TCS_assert.py

There's not much to them at the moment; only two states:

The LASERON state does nothing much check the laser status, and jump to the LASERFAULT state if there's a problem.  The LASERFAULT notifications are good at explaining what the problem is, and how to fix them.

NOTE: the TCS_ITMY is constantly in fault now because the ITMY CO2 laser has not been commissioned yet. I'm going to shut it down for the time being until we have something there to monitor.

We inspected the input windows of the pre-modecleaner tank.

The window in line with the main output beam shows signs of drag wiping.
The window in line with the PZT shows signs of damage and some general
damage from dust (see attached image).

In order to get a better view of the cavity mirrors, we need to pull
the pre-modecleaner out of its tank.  At the moment it's stuck in the
tank after being compressed for over 3 years.



Ed, Peter

Due to all of the latest commissioning of ETMY, the SDF had accumulated 40+ differences.  With Jeff's help we remedied numerous line items via making the ETMy ESD banks look like the ETMx ones.  This cleared out Kiwamu's settings leftover from earlier measurements.  I've also moved the ESD calibration filters from the 4 ETMY L3 ESD OUTPUT banks to the L3 LOCKING BIAS bank to bring it in line with the ETMx settings.  I've edited the burt ETMy safe.snap to capture some of the other commissioning work.  THere are now only 20 SDF diffs which I will continue to track down.

After staring at the data I posted yesterday with JeffK, he suggested we try blending lower on the ISI in RZ. I saw that the blend filter we use on the HAM's was installed already on ETMX, so I decided to take advantage of this morning's non-commissioning period to make some measurements. The results are, um, good. See attached plots. Blue (st1) and green (st2) are the nominal configuration, red(st1) and brown(st2) are the different blend in the first plot, which is calibrated to rad/rthz. Second plot shows the CPS (low pass) part of the two blends, blue is the nominal, red is the new blend. I'm only attaching the RZ data, but every other degree of freedom shows improvement, which I only kind of understand, considering the ground motion was worse after I changed blends.

I'm posting some plots of the performance of the BSC-ISI's. The attached pdf has 18 plots, the first 12 show the contributions of each control path to the performance of the ISI, shown against aligo requirements, sensor noises and ground motion. The order is St1 X (p. 1), St2 X(p. 2), St1 Y(p. 3),...  for x, y, z, rx, ry, rz. The configurations measured were offline, damped ISI, St1 ISI isolated / St2 damped, isolated (both stages), isolated with tilt decoupling, isolated with tilt decoupling and sensor correction, isolated with tilt, sensor correction and feedforward from HEPI. HEPI was off for the offline measurment as well. The blend filters used were the normal blend filters (the rdr compliment of filters with the T750 blend on St1 RZ). Please note that on the rotational plots, I used "paralell" ground direction (Y for RX, X for RY, Z for RZ). No, it doesn't make perfect sense, but X can be injected to RY or vice versa, and the BSC's have a coupling from Z to RZ, that we need to be aware of.

The last 6 plots show the final performance (i.e. our current configuration with damping, isolation, tilt decoupling, sensor correction and feedforward) for each dof for both stages.

Similar plots for the HAM's are next.