An electromagnetic shaker on the blue cross beams of the BS chamber produced greater upconversion than was produced by shaking of any other chamber or the PSL table (ITMY wasn’t shaken) (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=24194). I unsuccessfully tried to reproduce this upconversion using stage 2 ISI injections in X, Y and Z (I did not try RX, RY or RZ). Next I investigated the upconversion by injecting single lines with the EM shaker on the BS cross beams in order to find the most sensitive frequency band. Figure 1 shows the line injections that produced the most upconversion; they are located between 40 and 65 Hz. Lines injected with amplitudes between 1 and 2 orders of magnitude greater than normal produced broad features around the injection frequency and at harmonics, with amplitudes that were several times background in DARM. The next step will be to inject uniform bands in order to estimate the contribution of the 40-65 Hz vibration background to the DARM noise in the 80-200 Hz band. 

I spent some time looking at how we can reduce the DARM residual.

In the attached plot (template lives in evan.hall/Public/Templates/LSC/DarmResReduce_2015-01-23.xml), yellow shows the nominal DARM residual and estimated freerunning displacement.

Blue shows the residual after the addition of a 3 Hz resonant gain. I put this in LSC-DARM FM10, so the freerunning estimate should still be correct. [However, since the DARM filter bank is full, I had to overwrite some other filter. After this test was over, I reverted my changes and placed this RG filter in the LSC-OMC_DC filter bank for safekeeping.]

Red shows the residual after the addition of the 3 Hz resonant gain, as well as a microseism boost, which I put in LSC-OMC_DC. This affects the freerunning estimate, but the amplitude and phase changes at and above 10 Hz are minimal (less than 2 ° of phase change at 10 Hz).

I ran BruCo on one hour of data from last night. The report is available here:

https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_1137640217/

At low frequency, SRCL and DHARD_P are the largest contributions. SRCL is still a factor of few below the measured noise, while DHARD is very close around 14 Hz.

There is coherence with magnetometers (still far from the measured noise)

• EY_MAY_EBAY_SEIRACK at many lines below 100 Hz,
• EY_MAG_EBAY_SUSRACK_Z kind of broadband at  high frequency

No significant broadband coherence in the mistery noise region.

A 7.1 earthquake in Alaska at 10:30 UTC tripped many watchdogs. I reset all and went back to nominal working conditions for all seismic isolation at about 17:30 UTC.

Aborting a DTT measurement caused a lockloss - no good, although not a new phenomenon.

Since there are so many SDF diffs, I'm wouldn't put the IFO in Observe anyway, so I'm going to just leave it Down for the night.

Evan, Gabriele

There are too many SDF to accept, so we're just leaving the IFO undisturbed in low noise, starting 3:10 UTC

We noticed a small bump in DARM at about 360 Hz, coherent with PRCL. We added a 270-430 Hz elliptic band-stop. DARM improved and the coherence is almost gone. We are losing 9 degrees of phase at 50 Hz (PRCL UGF).

The filter is implemented in the SUS filter bank.

1220 - 1235 hrs. local -> To and from Y-mid 

Next manual overfill expected Monday, Jan 25th before 4:00 pm

First a bit of history: h1boot-backup is an identical machine to h1boot and can be used to replace h1boot if it were to fail. The /opt filesystem on h1boot used to be rsynced every hour to keep h1boot-backup current. Over the course of summer 2015 the rsync took longer, and became linked to the EPICS freeze ups of the front end computers. We suspect the main reason is that the NDS jobs directory became filled with many small files. Over Christmas I was doing select rsyncs manually, skipping these huge directories of NDS logs.

Over the last week I have reduced the number of files in these directories to a manageable number. This took some time because when a directory has 6.5 million files in it standard commands like find or ls wont work. I used customized C code to scan the files.

We now have NDS logs which look back over the past 7 days. The full rsync now only takes 15 minutes (it was taking either 10 hours or would not complete).

Because there is a non zero chance these fast rsyncs could freeze EPICS, I have scheduled the backups 3 times daily at 8am, noon and 6pm. If anyone sees epics freeze up at these times this would be the reason.

no restarts reported for both days.

Apologies for no transition entry. I was tasked with locking as soon as I walked in.

TITLE: Jan 22 EVE Shift 00:00-07:11UTC (16:00-23:11:00 PDT), all times posted in UTC

STATE Of H1: Down

SUPPORT: Sheila,Evan, Gabriele

INCOMING OPERATOR: N/A

ACTIVITY LOG:

00:28  HFD on site as a matter of protocol for a faulty fire alarm panel

00:30 another fire unit on site

00:42  reloaded ISC_LOCK Guardian

00:45  HFD Off site. Three firetrucks drove past corner station during lock

00:46  Dave B called and informed me of an AC failure. He’s contacting the proper folks.

01:13  Dick out of optics lab

01:32  Bubba back on site to handle AC issue in H2 building

01:37 BS ISI St2 watchdog trip

01:38  cleared HAM6 ACT watchdog accumulation counter

02:18 GRB alert

02:51  Bubba has reported there’s nothing he can do about the AC in the H2 building tonight so he’s leaving it off. He also went into the CER to check on the AC in there. He didn’t think anyone had been in there to check since the power outage. It seemed ok.

04:xx Relocked at NLN. Gabriele has turned me loose into the world!

We have a cooling problem with the H2 DTS building. Bubba came back in this evening to take a look at this, in the mean time we have powered down all DTS computers and DC power supplies for the weekend.

I retuned the MICH feed-forward path. I injected noise in SRCL and measured the transfer function to DARM: TF_SRCL_DARM. Then I injected noise at the feed-forward input, with the FF shaping filters off, but with SBVio1 and SBVio2 on. I measured the transfer function from SRCLFF_IN2 to DARM: TF_SRCLFF_DARM. The optimal feed-forward filter should then be -TF_SRCL_DARM/TF_SRCL_FF. The first plot shows the measurement and the fit. Again, I decided not to fit the sharp features due to the  bounce and roll filters.

I implemented the new filter in the bank 'newFF' and engaged it. The performance improved, as shown by the  reduced coherence. The peak at 3 Hz also reduced a bit. See the second plot: green no feed-forward; blue old feed-forward, red new filter. The last plot compares the old (blue) and new (red) filters. With the new filter, I also switched on an AC coupling (double zero, double pole at 0.1 Hz).

Sheila, Evan, Gabriele

We retuned the MICH feed-forward path. We injected noise in MICH and measured the transfer function to DARM: TF_MICH_DARM. Then we injected noise at the feed-forward input, with the FF shaping filters off, but with all the stop-band filters on and with the invBS filter on. We measured the transfer function from MICHFF_IN2 to DARM: TF_MICHFF_DARM. The optimal feed-forward filter should then be -TF_MICH_DARM/TF_MICH_FF. The first plot shows the measurement and the fit. We decided not to fit the sharp features due to the BS bounce and roll filters.

We implemented the new filter in the bank 'newFF' and engaged it. The performance improved, as shown by the improved DARM noise and reduced coherence. See the second plot: green no feed-forward; blue old feed-forward, red new filter. The last plot compares the old (red) and new (blue) filters. With the new filter, we also switched on an AC coupling (double zero, double pole at 0.1 Hz).

uSeism is approaching 1um/s and the winds have dies down to below 10mph.

WP5692 FRS4202

John, Kye, Gerardo, Dave:

I have modified the H0 vacuum overview screen to show an alarm border around bar monitor widgets. If the widet has no content, the alarm color is now visible in the border.