Krishna

As described before, we are testing to see if the seismometer mounted on BRS-Y platform sees better coherence with it as compared to the ground seismometer. Latest measurements suggest this may finally be happening. The first attachment shows the coherence between BRS-Y and the ground seismometer (red) followed by that between BRS-Y and the platform seismometer (blue). For the first time, blue is slightly better than red in a few places. The next page shows the spectra. Note the increased motion at 10-70 Hz, as mentioned previously.

The next attachment shows the coherence/spectra that was commonly seen before we bolted the seismometer feet to the table/platform. Once again, note the spectra at higher frequencies. It looks like we may have reduced higher frequency motion by bolting the feet to the platform.

The improved coherence after we bolted the seismometer to the platform supports two possible explanations: a) high frequency motion was causing the seismometer to move/slip on the table, which would cause low-frequency noise or 2) high frequency motion was down-converting through other mechanisms in the seismometer (flexure non-linearities).

In any case, we can try to improve/restore the thermal shielding and see if we can get even better coherence in order to do better tilt-subtraction.

Edit: The pink line is the current tilt-subtracted ground super-sensor, which is the ground seismometer minus tilt measured by BRS-Y.

The new temporary earthquake stops installed as a trial run worked great, they will be replaced with the real batch when it comes out of clean and bake on Monday.  Also, it appears that during the move/install the OFI alignment/balance went out a bit, so we are going to need to work on it in situ.

J. Kissel

Since HAM4's construction / installation stuff for this vent is complete as of yesterday's HWS Scraper Baffle install (LHO aLOG 39266), and the debugging of SR2's M2 OSEM today (LHO aLOG 39277), I took the afternoon to start B&K hammering all of the new / old baffle equipment and HWS mirror / lens mounts. Note, I deliberately skipped the SR2 cage, since nothing has changed on it since it was originally measured in LHO aLOG 12089, and I trust that Betsy and Travis successfully re-dogged and torqued bolts when they finished the relocation a few days ago LHO aLOG 39240.

Will post pictures and results next week.

Dan, Dave:

The recovery of the raw minute trends onto the new compressed ZFS file system completed at 16:30 as predicted. This data path was added to daqdrc for both h1nds0 and h1nds1 (default nds) which were both restarted. I tested that I could trend the outside temperature back to 26 May 2017.

Dan has setup the copy of the lion's share of the minute trend data over the weekend, should be completed by Monday.

Attached plot shows 30 day look back before the recovery (oldest data 18th Oct) and after the recovery.

49 channels added. 14 channels removed. List attached.

We hymned and hawed and decided that we prefer to have two metal sealed valves in series as a redundancy so I vented CP1's 55 L/s ion pump and swapped a second 1.5" valve in place of the 1.5" elbow that connects the ion pump assembly to the 1.5" pump port valve which is part of CP1.  I then pumped the ion pump to down and leak tested the new joints.  

This completes WP #7205

Fil, Patrick, Dave:

Following a BRS related power glitch at EX at 14:52 PDT this afternoon, the h1iscex computer lost connection with its IO Chassis. The front end recovery process was: stop models, take out of Dolphin fabric, power down computer, power cycle IO Chassis, power up computer. The system recovered with no problems.

In addition to the h1iscex IO Chassis, the following are also powered by the 24V power strip in the ISC rack; the two RF-Oscillators and the three Slow-Controls Chassis (End Station 2, End Station3, ISC Common). The attached dataviewer plot  shows the IOP model going down at 14:52 PDT (and latching off until I rebooted) and a beckhoff temperature signal momentarily glitching and recovering.

Fil is investigating the power glitch.

TITLE: 11/03 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
LOG:

15:44 - 18:14 UTC TJ to HAM3
15:51 UTC Snovalley through gate
15:51 - 17:03 UTC Jason to LVEA cleanroom with part, then adjusting PSL environmental controls
15:51 UTC Krishna to end X to work on BRS
15:53 - 15:59 UTC Travis to LVEA West bay to look for cables for SR2 OSEM
16:25 - 17:13 UTC Hugh to end Y to center BRS colocated T240 masses
16:26 - 17:30 UTC Travis to HAM4 to swap cables for SR2 OSEM
16:39 - 17:30 UTC Jeff K. to HAM4 with CDS laptop to help Travis
17:23 UTC Tour in CR
18:04 - 18:12 UTC Jason to optics lab
19:18 - 20:51 UTC Gerardo to HAM5 to unlock the OFI and install EQ stops
19:41 - 22:02 UTC Terry M. to squeezer bay
Dave reports chiller alarm at end Y, Bubba notified
20:57 - 23:03 UTC TJ and Jim to HAM2 to build and install baffle
21:30 - 22:48 UTC Rakesh walking around LVEA
21:54 UTC HEPI L0 pump controller crashed, Hugh and Filiberto investigating
22:07 UTC Jeff K. to HAM4 to B&K hammer
22:16 UTC h1iscex IO chassis power glitched. Something Krishna might have done at end X. Dave went to end X and restarted the frontend.

The following summarises the characteristics of the output Faraday isolator.  The
power meter used was an out of calibration date, Ophir 1Z02411 power meter, S/N 73375
with filter 19603 S/N 132872.  Microwatt level measurements were done with the filter
removed.

    An incident laser power of 10 mW was used to avoid the possible saturation of the
photodiodes used.


  

    
 Item 
    
 photodiode 
    
 power meter 
  
  

    
 transmission 
    
 98.1% +/- 0.6% 
    
 94.8% +/- 0.1% 
  
  

    
 back-scatter isolation 
    
 657 ppm 
    
 610 ppm +/- 5 ppm 
  
  

    
 TFP AR reflection 
    
 N/A 
    
 N/A 
  
  

    
 isolation 
    
 61.1 dB - 58.9 dB 
    
 69.7 dB - 70 dB 34.9 dB - 35.0 
  
  

    
 backscattering 
    
 24.4 ppm +/- 0.5 ppm 
    
 N/A 
  
  

    
 squeezer path transmission 
    
 99.8% - 98.4% 
    
 93.3% - 93.5% 
  


Some notes about the measurements. The backscattering could not be measured with the power meter.
The beam reflected from the AR surface of the thin film polariser could not be separated from the
prompt reflection in the clean space available, and was only visible with a CCD-based IR viewer.


  

    
 motion 
    
 frequency 
    
 Q 
  
  

    
 vertical 
    
 1.49 Hz - 1.50 Hz 
    
 22 -/+ 1 
  
  

    
 longitudinal 
    
 0.62 Hz 
    
 22 
  
  

    
 pitch 
    
 1.05 Hz 
    
 17 
  
  

    
 yaw 
    
 1.05 Hz 
    
 20 
  
  

    
 side to side 
    
 0.63 Hz 
    
 15 
  



  Gerardo / Peter

Attached are the current EPICS alarm level settings for each FMCS channel. These are the settings used by the alarm handler at the operator's station and may differ from those used for phone text alerts.

WP7161: Dan, Dave:

Following Dan's suggestion, the SATABOY units have been split into two non-equal parts. The first is a small QFS file system (written by CDS, read by LDAS), which will hold the framed files' MD5 check sum files*. The second is a larger ZFS file system to hold the archived raw minute trend files (written and read by CDS).

The reason for the split is to perform firmware data compression, using the ZFS compression utility, for the archived raw minute trend files. Dan has found that GZIP-LEVEL5 compression gives us the 'best bang for our buck' in terms of compression ratio and cpu loading. We are expecting a compression ration of around 7.

Once the past 6 months of archived raw minute trend data have been copied, I'll reconfigure h1nds1 to serve these data.

In Detail: the SATABOY has 12 2TB HDD. They are allocated thusly:

* - writing the MD5 files to this location requires a daqd code change, I have submitted ECR-E1700382

J. Kissel, T. Sadecki
FRS Ticket 5058

Travis replaced the in-vacuum, 4xDB9-to-DB25, "quadrapus" cable between the OSEMs and the "seismically-responsible-suspension (SRS)" in-vac cable for the H1SUSSR2 M2 stage (see LHO aLOG 39275) in order to further investigate the problems with UL's inability to actuate. Replacing this cable has fixed the issue.

I attach corroborating evidence.
(1) The range-of motion test results. Where we did not see any motion during driven offsets on the UL chain yesterday after replacing the OSEM itself (LHO aLOG 39263), we now see actuation response on all M2 OSEMs
(2) The single-frequency sign wave test results. Where we saw no coherence or displacement in the UL OSEM ASD yesterday, we see plenty today and it's virtually identical to the known-good LL response.
(3) The full suite of M2 to M2 transfer functions. We no longer see any unexpected cross coupling between P and Y, and the response to drive in all DOFs is larger, now that we're actuating with 4 OSEMs instead of 3.

We may finally close this FRS ticket!

Other Notes:
- Given the new quadrapus cable affects the response of all OSEM sensors on the cable, we remeasured open light currents, and updated the OSEMINF calibration infrastructure.

OSEM   Open Light Current     OSEMINF OFFSET      OSEMINF GAIN
             (OLC)            (-1 * OLC / 2)     (30000 ./ OLC)
         [ADC Counts]          [ADC Counts]         [um / um]
UL           24546            -12273                 1.2222
LL           19482             -9740.8               1.5399
UR           17731             -8865.4               1.692
LR           19314             -9657.2               1.5532

- The (modified) triple-acquisition driver for this stage was set to its highest actuation strength for these measurements, state 2.

- Now that SR2's M2 stage is fully operational and may potentially be a globally control, we will need to balance the actuation strength by applying non-unity COILOUTF gains calculated via methods described in LHO aLOG 13203

- If we're interested in any frequency-dependent drive DOF decoupling (a. la. LHO aLOG 32503), I've now tuned this set of templates to get much better coherence than what had previously been in this SUS's SAGM2 folder (and they now store the M3 sensors such that we can export the M2-to-M3 transfer function). The data can be found here:
    /ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM2/Data/
        2017-11-03_1816_H1SUSSR2_M2_WhiteNoise_L_0p01to50Hz.xml
        2017-11-03_1816_H1SUSSR2_M2_WhiteNoise_P_0p01to50Hz.xml
        2017-11-03_1816_H1SUSSR2_M2_WhiteNoise_Y_0p01to50Hz.xml

- All data and updates to "plotall" scripts have been commited to the SusSVN repo in the appropriate places.

After swapping the AOSEM for SR2 M2 UL earlier this week, and learning that it was not the culprit (alog 39263), I replaced the M2 stage Quadrapus cable.  JeffK checked it on the fly while I was in the chamber and verified that it seems to have fixed the issue.  Cable that was removed was D1000234-v4-00-903.  New cable is D1000234-v4-00-S1106125.  

After remounting the T240 on the BRSY table with through bolts, rather than just sitting on the table with pointed feet, we 'centered' the masses--this was Wednesday afternoon.  This morning I checked again and the mass centering positions were all  about 1 volt.  Not terrible but above action level had these been on an ISI mounted T240.  So I centered it again this morning.  A couple minutes after expressing the 5v required to initiate centering, the readings were at 1 to 7 percent of 1 volt.

(Mark, Tyler, Peter, Gerardo)

The old OFI was extracted out of HAM5 using the HAM installation arm.  Once out of the HAM a lift was used to lower it onto a table for temporary storage.

The new OFI was installed using the lift to position it on the HAM installation arm, then set into the HAM on top of the height adaptor.  The height adaptor was not removed to maintain the aligned position.  The OFI was fasten to the height adaptor and all fixing bolts were torqued, also 2 vibration absorbers were moved from the old OFI to the new one.  The OFI is "locked" in place using the transport shims, and tomorrow with the new earthquake stops it will be "released" giving us an opportunity to visit its suspended alignment.

Attached is a photo of the new OFI as it was being installed, yup! There is not much room, the arm was 1/2 inch away from black glass baffles on one end,  and the other end very close to the ceiling of the chamber, to move the arm out we resorted to the removal of a yoke arm and it worked like a charm!

Noticed this swing in PSL table North temperatures.

Also seen in AOM power, and slightly in IMC power in (though IMC power in is low, at 60mW).

Rotation stage has not been moved, and PMC Trans drop is reason we are at 60mW into HAM1.

Depending on what beam quality is needed for work on the SRC that's coming up, temperatures may need to be stabilized in the PSL, to stabilize power.

Hugh, Jim, Krishna

This is regarding the idea of placing a seismometer on the BRS-Y platform in order to improve coherence and hence tilt-subtraction. The brief summary is that we found excess low-frequency noise in the seismometer when it was placed on the table on BRS-Y. Hugh had attempted to reduce the noise by adding thermal insulation to the table and the instrument. The last alog on this is 35426.

In the recent data I looked at, this excess noise looks non stationary - it seems to get worse with elevated wind. This suggests it is likely not thermal. The seismometer data shows that the table has much higher motion in the 10-100 Hz as compared to the ground. Since the seismometer isn't held securely on the table, it is possible this excess high-frequency motion is causing it to move ever so slightly, which could look like excess low-frequency noise (step changes). We are attempting to mount the seismometer securely to the table using M10X1.0mm threaded rods and holes to be machined into the table. Results and plots will be posted in a few days.