Andy Lundgren sent out an inquiry via email about lines at 1180 Hz and 1150 Hz. I looked for these lines in the coherence tool, and I didn't see any evidence of the 1180 Hz line, but I did find a very sharp line at 1150 Hz on the following channels:

H1:LSC-MCL_OUT_DQ
H1:LSC-MICH_OUT_DQ
H1:LSC-PRCL_OUT_DQ
H1:CAL-CS_CARM_DELTAF_DQ
H1:CAL-CS_IMC_DELTAF_DQ
H1:CAL-CS_MICH_DQ
H1:CAL-CS_PRCL_DQ
H1:CAL-CS_SRCL_DQ
H1:LSC-DARM_OUT_DQ
H1:LSC-REFL_SERVO_CTRL_OUT_DQ
H1:OAF-CAL_CARM_AO_DQ
H1:OAF-CAL_CARM_X_DQ
H1:OAF-CAL_MICH_DQ
H1:OAF-CAL_PRCL_DQ
H1:OAF-CAL_SRCL_DQ

If you want to look for yourself, you can find the full coherence tool output for the May 2 locks here:
https://ldas-jobs.ligo-wa.caltech.edu/~nathaniel.strauss/HIFOX/LineSearch/H1_COH_1114579968_1114784433_1000_webpage/

SDF Cleanup

If channels are removed from your model/code whatever, unless you take your system down to the safe state and makeSafeBackup to generate from scratch a new safe.snap (and most of us know the problem doing that causes,) the SDF system will go yellow for CHANS NOT FOUND.  Okay, maybe no big deal but green is better than yellow when scanning our configuration control tools and we should green these up at earliest opportunity.

There is a way to clear these out with having to take the system down to a 'safe' state for the new snap.

You can just go to the SDF TABLE and while there you might as well look at the CHANS NOT FOUND list and make sure they make sense (yes, we did remove those channels from the model, e.g.)

Then from that medm, open the SDF SAVE SCREEN

Insure the SAVE TABLE selection is TABLE TO FILE and the FILE OPTIONS SELECTION is OVERWRITE

Press SAVE FILE

This step overwrites the safe.snap file removing the not found channel records.  Little wierd though, on the SDF_RESTORE screen (available from the TABLE screen as well,) it does not show a Modified file detected message, but, it has updated the time, as if it had 'Restored' to that time.  But you will notice that your list of Not Found Channels have not cleared.  Maybe this is explicitly intentional or is maybe a trivial bug.

Now on the SDF_RESTORE screen, press LOAD TABLE, and, all the NOT FOUND channels should clear.

However, there may be remaining NOT FOUNDs that will crop back up:

If the NOT FOUND CHANNELs list contains fields as opposed to just records, that is H1:HPI-ETMX_GUARD_CADENCE.HIGH (field) versus H1:HPI-ETMX_GUARD_CADENCE (record), this process will not remove the field lines from the safe.snap.

Still need to test this (Barker is on it) but, maybe the next time the front end starts, these fields will again become a CHANS NOT FOUND and our green lite will revert to yellow.

This happens because the FE code reads the safe.snap and strips out the field lines and saves them in a safe_alarms.snap file in the target area.  Then when it saves the safe.snap, this field list is just tacked onto the end of the safe.snap record list.  So your safe.snap will always contain these non existent channel field lines.

The fix to this problem is the following, before doing the steps above, (you could did it after but you'd be saving & loading twice) go to the target area and remove the appropriate field lines from the safe_alarm.snap file (currently writable only by controls.)  Once these are gone, proceed as above in the SDF SAVE SCREEN.

After adding the OFFLINE state, alog 18081 , it was found that the offsets will cause drift in this state as well like in alog 17929 . So, after talking to Kiwamu, I changed it to disable the offsets in the OFFLINE state as well as in the FAULT state and removed it from the DOWN state. The offsets are still enabled in the LOCKED state as before.

Scott L. Ed P. Chris S.(Cris M.1/2 day)

5/4/15
Cleaned 21.3 meters ending at HNW-4-028. Removed lights and relocated all equipment to next section. Began vacuuming and spraying bleach/water solution.

5/5/15
Cleaned 73 meters ending 14.5 meters north of HNW-4-031.

Evan, Sheila

Tonight we have some evidence that the work on recylcing gain has helped us, Evan will attach the DARM spectrum. 

Restoring the green camera offsets to the ones used during the mini run means that we can again lock with a recycling gain of ~37.  These wrong references and the bad alignment that went with it has probably caused some of the frequent lock losses of the last two days, and headaches in turning on ASC in full lock. Hopefully we can leave all green references alone for at least a week and see that they really do bring us back to a good recycling gain consistently.   My comments from yesterday about trying to figure out what drifts in green should be ignored.

We did some injections of noise into SRCL with all of our boosts on (MICH L, SRCL, DHARD P+Y), and the AS_C to SRM+SR2 loop at a 4 Hz bandwidth.  38 W/W recycling gain.  UTC May 6 11:48-11:53 UTC, no SRCL FF but MICH FF was on.   The goal was to see how stationary the coupling is now.  

We also restored some of the ASC cut offs that were deleted during the recycling gain work, CHARD PIT +YAW, DHARD P+ Y (for DAHRD P we are only using one of the two cutoffs we had, a pair of complex poles at 12 Hz, we don't have enough phase to use the 8 Hz cut off anymore so we wil need to redesign it if we need it)

Other business

• We have had several locklosses during the analog CARM transition in the past few days.  We edited the guardian so that the feedback is engaged as soon as the CM board input is enabled, this seems to have reduced the large kick that the BS and SRM were getting during this step.  
• After maintenance today we saw that the H1:ASC-Y_TR_B_SUM_OFFSET offset had been changed, probably a bad safe.snap.     We redid dark offsets for TRY B on each individual segment, NSUM, POP A LF, POPAIR A LFand POPAIR B LF.  We also redid the normalization of each arm transmitted powers in a single arm lock, this meant changing  H1:LSC-TR_X/Y_QPD_B_SUM_GAIN.  We have accepted these changes in SDF.
• We also noted that the power on POPAIR A LF when MICH is locked on a dark fringe is 3.27uW, while the power on POPAIR B LF is 5.2 cnts, this doesn't seem to be calibrated.

We think that some usefull next steps on the list are

• Increasing SRM WFS gain, we made an attempt at this tonight but had trouble, and plan to come back to this task this evening
• picomotors for TMS Y QPDs when the recycling gain is good, which should allow us to close the ITM loops again. I dont' think that I aloged this in the past, but the strategy that worked for TMS Y QPD centering was to steer M14 to center on TRB, then steer M4 for TRA
• Add the remaining ASC cut offs back (INP1, PRC2, PRC1)
• using Gabriele's script to remeasure the ASC sensing matrix with good recycling gain
• 15-20 Watts

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.

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.