We don't seem to be ablke to use the lockloss tool tonight, I get this message.  I'm not sure if this is realted to  bug  834, or to some maintence activity today. 

 sheila.dwyer@opsws4:~/Desktop/Locklosses$ lockloss select

Kiwamu, Keita, Elli

Today locked aux laser to swept frequency offset to carrier laser using PLL.  A network analyser provides a swept LO signal (7dBm into ZFM-4+ frequency mixer, or 10dBm if using a splitter.)  The RF signal is the beatnote of carrier and aux laser frequencies, which is demodulated against the LO using a ZFM-4+ mixer and 1.9MHz low-pass filter.  This error signal is sent to an LG1005 servo controller, P-I corner 10kHz, gain 4.1, LFGL 50dB.  We amplified the RF sigal (1611 pd on IOT2R) using 17dB ZFL-1000+ RF amplifier, as the error signal of the PLL was very weak; this made locking the PLL easier.  The PSL pwer was 2.3W, the aux laser power set to 500mW.

We noticed changing IM4 alignment during initial alignment changes alignment of beams onto the 1611 photodiodes enough that a quick realignment may be necessary.  This is a little painful as this alignment is done on IOT2R, where the aux laser is.  The aux laser frequency takes some time to settle after opening the table.  Again today we used the 1611 pd on ISCT1.  I unplugged the power to the bbpd-refl photodiode (the 3f refl pd) in order to power the 1611, and then changed this back again after I was done.

To take the measurement we locked DRMI 1f with ASC.  To engage PRC1, we adjusted the centering offset on Refl-DC WFS.  We looked at the signal reflected from DRMI using a 1611pd on ISCT1 on the reflair path, and measured the transfer function of this reflected light intensity over the LO frequency.  Could see transmission dips every ~2.6MHz, which correspond to the auxiliary laser resonance in PRC.  Also some other peak which may be higher order mode.  Currently producing a model to make sense of this, and to decide what frequencies will be useful to measure at.

After the whitening chassis was swapped, the worst problem went away, i.e.  QPDA seg2 looked healthy.  However, smaller problem, i.e. the dark noise level of QPDA seg4 being about a factor of 2 or 3 higher than everybody else (attached top), persisted.

Disconnecting QPD cable from the transimpedance box did not change the behavior, but disconnecting the cable between the transimpedance box and the whitening chassis did.

Anyway, QPD transimpedance amps was also swapped and everything looks good (bottom).

Removed and replaced the annulus Ion Pump, aux pump cart will remain pumping on annulus system for some time.

As of this entry the current for this pump is at 3.02 mA.

Reset HAM5 and ITMY.

Added 15 channels. Removed 50 channels.
2 channels remain unmonitored:
H1:SUS-SR2_LKIN_P_OSC_SW2R
H1:SUS-SR2_LKIN_Y_OSC_SW2R

07:54 Elli to IOT2R
08:08 Jeff B. to LVEA to pull data out of humidity/temperature monitor in desiccant cabinet
08:14 Filiberto to end Y to swap whitening board for ISC
08:14 Karen to end Y to clean
08:36 Jeff B. back
08:56 Gerardo to LVEA to move pump cart in preparation for replacing annulus ion pump on BSC1
09:06 Karen and Filiberto leaving end Y
09:12 Jim B. finished updating GDS tools
09:30 Nutsinee to LVEA to find Elli
09:32 Kiwamu starting calibration of ETMX and ETMY optical levers
09:39 Keita checking swap of whitening board, misaligned ETMY
09:41 Nutsinee to LVEA to work on HWS table by HAM4
09:44 Gerardo out of LVEA
09:47 Dave restarted the guardian machine
09:49 Kyle to end Y to start bakeout of BSC6 RGA
09:55 Keita done on ETMY, to LVEA to talk to Elli
09:56 DAQ restart
10:00 Robert to LVEA to setup for PEM injections
10:01 Jim B. finished update of command line nds tool
10:23 Cris to end X
10:34 Kiwamu done optical lever calibration
10:40 Gerardo beginning replacement of BSC1 annulus ion pump
10:41 Nutsinee misaligned TMSY
10:58 Guardian restarted
11:18 Jim W. installing new ISI filters on ETMY
11:37 DAQ restart
11:47 Kiwamu calibrating PR3 optical lever
11:59 Kiwamu and Jason to LVEA to check whitening settings on PR3 optical lever
12:10 Cris back
12:23 Robert to end Y to set up for PEM injections
12:25 Kyle back from end Y
12:28 Kiwamu and Jason back
12:31 Kyle to LVEA to help Gerardo
12:49 TJ to end X to turn BRS damper on
12:59 Robert back
13:30 TJ back
13:37 Keita to end Y to look at transimpedence amplifier for QPDs
13:41 John to LVEA to look at platform Gerardo is using
14:02 Jeff K. to CDS electronics high bay
14:04 John and Kyle to end X mechanical room to change voltage on ion pump controller
14:05 Gerardo to LVEA
14:22 Gerardo back
14:42 John and Kyle back
15:08 Keita back from end Y
16:14 Elli, Keita and Kiwamu have locked DRMI and are taking a measurement by HAM1

To help with diagnosing the large cpu loading we were seeing on h1guardian0, at Jamie's request I have installed munin on h1guardian0. It is currently running with the default configuration and reporting its output to the URL:

https://lhocds.ligo-wa.caltech.edu/exports/munin/h1guardian0/localdomain/localhost.localdomain/index.html

h1asc model has a modified filter file which has not been loaded. The change is to ASC_SRC1_P and ASC_SRC2_Y. At some convenient time in the future these chages should be loaded or removed.

h1iopasc0 infrequently shows a CPU max of > 15uS which I think is a new behaviour. It has happened twice in the past week.

Guardian is including TCS_ITMY in its channel lists (e.g. H1EDCU_GRD.ini) but this node is not running. This is causing the DAQ EDCU being purple.

HWS ETMY is missing an EPICS channel which does exist in ETMX. This is also causing the DAQ EDCU to be purple.

Aidan suggested that I align the irises to the sled beam rather than alinging the sled beam to the irises so I went in and redid the alignment for the ITMX HWS optics. I blocked the green light, centered the sled beam to the mirrors/lenses and adjusted the irises accordingly. Then I let the green light through, fine tuned the irises positions and made sure the green and the sled beam are reasonably well overlapped if not right on top of each other (SRC aligned, BS aligned, ITMX aligned, TMSX alinged, ETMY misaligned at this point). The green beam is hitting the HWS. However, the streamed imagees don't show any decent return sled beam. Given that the incoming green light overlaps the outgoing sled beam whatever is causing the return sled beam to be off is likely in vaccum. Greg also noticed the green beam coming down the ITMY periscope changed position significantly compare to last week. So we agreed to not adjust the corner station HWS optics any further until we are sure that the SRC optics won't change the alignment again. The Hartmann waveplate is off at the moment for ITMX.

John, Kyle

Don't want pressure to vary as the result of varying IP12 voltage output -> Wider community using X2 BT pressure as indication of possible leaks being introduced from BT cleaning activities on X2 -> Fixed voltage at 7000V (same voltage as Y-end)

The pressure at X END has been bouncing around due to the programmed voltage steps of the main ion pump controller. In order to stabilize this we have set the voltage to 7 KV. This is also the same setting as the Y END pump.

The immediate response has been an increase in pressure to ~2e-8 torr. We expect the pressure to fall back to the low e-9 range as the pump sputters and exposes fresh surfaces.

During maintenance this morning we pushed a fairly minor guardian upgrade.  We are now running:

• guardian r1447 (+2 minor MEDM screen changes from r1445 that is running right now)
• cdsutils r474

Primary bugfixes or new features:

• Improve SPM checking.  This should get rid of the "SPM flickering" that was being reported at LHO.
• MODE 'EXEC' is now called 'AUTO', to elliminate ambiguity with OP.
• Fix node supervision logging to properly time stamp all logs.
• Add TIME_INIT and TIME_UP channels that record when a node was initialized, and how long it's been up.

The last two are to help debug some of the intermittent issues we've been seeing with node processes hanging for unknown reasons.

The node status indicators on the main GUARD_OVERVIEW screen also now have a couple of extra indicators lights, for STALLED state of node, and if there are any SPM diffs:

The BRS settled down to about +/-7000 counts, so I went down to the end station and turned the damper back on but I did not do the gravity dance with it. It should still take a bit for the damper to settle the BRS down to its nominal range so it is not yet usable.

Jason, Kiwamu,

PR3 oplev has not been properly behaving. We don't know when it ran into the issue. We will take a close look in the next maintenance Tuesday as we are suspecting a bad QPD and/or bad electronics.

[Cross-coupling issue]

Currently the symptoms are that:

• Moving the PR3 suspension in pitch shows a large cross coupling to yaw (more than 50%) and the same is true when moving the suspension in yaw.
• When each segment receives equal amount of light, segment 2 seems to respond much lesser than everyone else to the suspension angular motion.

At this point, we are not sure if this is due to a bad QPD segment or some kind of electrtonics issue.

[Dip switch confusion]

Independently of the cross-coupling issue, we found that a dip switch for the seg3 whitening filter had been set differently than the rest of three segments. We thought this would fix the cross coupling issue at the begginig, but switching it to the position that everyone else have been did not solve the issue because the cross-coupling behavior which is described above arose in turn. It is unclear how long the dip swtich has been in this configuration. Note that the last maintenance activity on PR3 was performed almost a month ago (on 7th of this April, alog 17722)

On Saturday, I was able to get some data on the effect of different blend filters on DARM.  It looks like we probably don't want to be using the 45mhz blends, or they need some re-working to reduce their low frequency performance. The attached plots are DARM  from 2 lock stretches on Saturday. This is the CAL CS DELTAL spectra, which Jeff helped  me calibrate, hopefully he'll explain in a comment. Blue traces are both end stations with 45mhz blends, orange traces are both end stations with 90 mhz blends, black is the ground. Ground was pretty similar between the 2 cases, range was similar, though slightly higher with the 90mhz blend, possibly better alignment? First plot is .01 hz to 3 hz, where most of the action is, the second plot is 1hz to 100hz.

The first plot  shows the 90 mhz blend does as well as the 45mhz blend down to .3 hz, then does a factor of several worse until ~50mhz, where the gain peaking on the 45mhz blend causes more motion.  Above 1 hz the 90mhz blend shows more RMS, I'm not sure of the cause, but there are features visible in the second plot at about 8-15hz that I don't understand. But they are probably not due to the blend change.

J. Oberling, S. Doravari

With the HAM6 activity closing out, we took advantage of the window and tweaked another laser and swapped it into SR3.  The SN of the new laser is 199.  This was installed in the SR3 optical lever so we will have data for a direct comparison between the stabilized diode laser here at LHO and the fiber-coupled HeNe in use as the LLO SR3 optical lever.  We will begin monitoring this laser tomorrow after it thermally stabilizes overnight so we can perform, if necessary, final tweaks to the laser power to finally stabilize the laser.