J. Kissel

I've B&K hammered the response of a bunch of other stand-alone components in HAM2: New MC13 Table Baffle, PSL DownPeriscope, MCREFL Periscopes, and New ISI Table Baffles. The prognosis is not good. Every component aside from the PSL down-periscope has resonant features below, if-not-well-below 150 Hz -- the original requirement from the SEI team to keep ISI 30 Hz UGF control loop design possible. Granted, the MC REFL Periscopes haven't really changed, but this data shows that (a) they are different from each other, and (b) that Periscope 2 is confirmed rattly mess. I can only hope that we can some how stiffen & and damp, instead of just shoving viton everywhere. I fear it's far too late in the schedule...

This being said, I must give props to the SLiC design team for ramming through an incredibly quick design-to-installed turn-around, and I appreciate that not everything could have been thought. We know from LLO that all this new baffling is doing the right thing as far as scattering goes.

See the .pdf for transfer functions.

I'll note that *everything* I hammered in HAM2 (including PRM and PR3 from LHO aLOG 39212) shows these resonant features at ~10.6 and 12.4 Hz. However, the ISI table baffles (a.k.a. beard baffles) seem to show this feature more prominently, and their mounting looks ... less-than-stiff ... so my guess is that since the accelerometer is mounted to the table in these measurements, they're coupling to every measurement. BUT, this is just a guess. I have a tough time believing that there's enough moving mass in those baffles to resonate as low as 10-12 Hz.

Aside from this common feature, I list the remaining prominent low-frequency features here in tabular form for future reference:
    DOF                       IFO Y                                    IFO X
    MC1/3 Table Baffles       [21.5 29.38 44.62]                       [29.62 36.88]
    PSL Down Periscope        [238.4]                                  [269.8]
    ISI HAM2 Table Baffle     [12.38 40 60.75]
    MCREFL Periscope 1        [124.6 124.8 140.8       194.6]          [22.00       42.25 141.2 167.9 195.1 ]
    MCREFL Periscope 2        [31.75 124.6 142.6 167.8 201.4 285.0]    [22.38 31.25 48.12 143.5 167.6 201.6 223.6]

Pictures are attached to guide discussion and aide any repeat measurements in the future.

• PSL beam aligned to the IMC using the new MC1 iris
• MC1 and MC2 alignment slider values are within 40urad of previous values
• MC3 alignment sliders have changed significantly
  • BEFORE: Pitch slider: -3911, Pitch OSEM: -3606, Yaw slider: -490, Yaw OSEM: 500
  • AFTER:    Pitch slider: -461, Pitch OSEM: -874, Yaw slider: --2260, Yaw OSEM: -1356
• alignment snapshots attached

- Ed, Keita, Cheryl

[Spelling Ed from DAY Ops Shift duties so he can join IO Team for HAM2 activities.]

Afternoon's Activities:

• 19:34 Transitioning LVEA to Laser HAZARD (Keita)
• 19:35 Monthly Hanford Testing automated call received
• 19:35-22:40 IO Team heading out to HAM2 (Cheryl, Keita, Ed)
• 20:08 ITMx (BSC3) work cont. (Betsy, Travis)
• 20:39 BRS EX upgrade work (Krishna)
• 20:55 OFI work cont (Gerardo, Peter K)
• 21:06-22:15 Ion Pump cable short circuit test at Y2-8 (i.e. ~250' from EY) [Kyle, Chandra]
• 21:06 HAM4 Baffle Work & LVEA part search (TJ, Jim)
• 21:08 "Noise Eater Out Of Range" 
• 22:15 MY Trip (Kyle)
• 22:40 LVEA is Laser SAFE (Cheryl, Ed)

Kyle R., Chandra R. 

Previous attempts to test for a high voltage cable connector short circuit were to no avail as the ion pump controller wouldn't energize the cable without the cable connector being mated to the pump connector (SHV Safety Interlock).  Today we defeated this safety interlock by disconnecting the HV connector from the pump and installing a mating-sex connector in place of the pump connector.  By doing this, the mating-sex connector depresses a spring contact within the HV cable connector and "fools" the controller into thinking that the cable is connected to a grounded ion pump.  Anywhoooo....this approach worked and the non-terminated HV cable would now energize.  The result was confirmation that the short circuit is, in fact, internal to the pump-end HV cable connector as the controller's output was power limited, 700V @ 0.5 amps, while not connected to the ion pump.  

As such, we'll ask the EE/CDS folks to redo this pump end HV connector as they have a much better track record of doing this successfully than we do!  

S Cooper, J Warner

I've been using a particle swarming script developed by Conor, to design some sensor correction filters in different environmental conditions., the method used by the script is described in G1700841. 

I chose a starting point of GPS time 1193385618 (8AM 30th October 2017 UTC) and used data for 2 hours on ETMY. During this time the microsisem was around 0.2-0.3 um/s and the wind speed was around 10m/s. I configured the swarm to have 4000 particles, set the RMS counting from 2Hz down to 1mHz, set minimum and maximum Q's to be 0.05 and 5 respectively and set the gains to range from 0.95 and 1.05. The result of this swarming produced the filter shown in blue in the first plot and its complement in red, plotted against the sensor correction filters currently used (Filter Module 5 CML BB). 

For these conditions, on this chamber the ending velocity RMS (how we're measuring how well the filter performs) is basically equal to the sensor correction filter currently used. Nevertheless Jim and I will try this filter out on ETMY and see whether this has any problems / benefitsover the old filter overnight on ETMY.

II 1127 & WP 7195

Returned the model to nominal configuration to allow testing/troubleshooting of the rogue excitation problem associated with the C2 coil driver.

Filters are changed and after a couple weeks of circulating just up at the Pump Stations, the valving has been returned to allow flow through the LVEA piping.  The Actuators are still isolated from the flow and I'll keep the system like this for at least a week or so to further bleed the piping and clean the fluid.  Can't really do any testing until the HEPIs are unlocked so there is no rush to open up to the actuators.

J. Kissel

I've taken new, more comprehensive B&K hammer response measurements of the H1SUSPRM and H1SUSPR3 cages, now that they have newly installed (what I'm calling) Venetian Baffles (see attached HAM2_NewBaffling_WithLabels.pdf for names of baffles) whose installation was finished last week LHO aLOG 39170.

These baffles have pretty high-Q, low-frequency drum-head / longitudinal resonances (roughly aligned with ISI / IFO Y axis).
  
    PRM Upper: 42.38 & 46.75, 91.00
    PRM Lower: 42.38 & 46.75, 75.62 

    PR3 Upper: 36.75, 75.6
    PR3 Lower: 36.75, 83.12 

My guess is that the lower frequency of the modes are the baffles bending in longitudinal in concert on the Venetian bracket, and the upper frequencies are their individual longitudinal modes. This mode-shape guess is based only on intuition, and that the lower frequency modes are seen in both upper and lower excitations.

The cage's transverse modes appear to be relatively unaffected by the new baffles. I'm little surprised it hasn't stiffened up any of the transverse modes; oh well.

These resonances have been identified by comparing against the history or cage resonance measurements for each of the SUS -- see the three pdfs: 
    2017-10-30_H1SUSPR3_CageResponse.pdf
    2017-10-30_H1SUSPRM_CageResponse.pdf
    2017-10-30_H1SUSPRMvsPR3_CageResonance_Comparison.pdf

Note, also new with these measurements -- data out to 1.1 kHz. The former data is from 
LHO aLOG 6014 -- VA ON vs OFF data for H1SUSPRM and H1SUSPR3
LHO aLOG 8654 -- Former Cage Baffles on H1SUSPR3

Photos attached (and remaining HitLocations.pdf) are for historical reference for future repetition.

WP7195 Hugh, Dave:

Hugh reconnected the CD_[V2,H2]_V inputs to the 3rd ADC chans 2,3 (they were grounded). The model was recompiled, installed, and restarted at 12:04 PDT. No DAQ restart was needed. I cleared various IPC errors on receivers of ISI-HAM5 sender channels post-restart.

Travis and I walked down X-beam manifold in chamber to investigate unknown contamination on the interior wall that Betsy had spotted, a few feet away from oplev flange/baffle. We found two dark brown/black spots near the top/roof of tube, each about the size of a quarter. I was able to scrape some off with a little flat head screw driver and then wipe with IPA wipes to improve/reduce the spots (grinding is needed to remove all). Before and after pictures attached. I wiped until there was no evidence of contaminate on wipe. Then we noticed the side wall was splattered with the same material (photo attached). Its first layer comes off by scraping with a tool, but we did not spend time scraping all 50-some spots. We can go back in to scrape these other spots, but I would first like to send sample in for analysis.

Note that we have seen evidence of higher pressures in XBM (compared to YBM) when it's isolated from beam tube. Could be outgassing from this material. Travis and I inspected YBM and did not find this contaminate.

Late last week, we took control of AHU 1 & 2 in the LVEA with the new HVAC controls. This has been a long process and is actually still on going in so far as we still have to take control of AHU-3. 
I have been monitoring the LVEA all weekend and in an effort to stabilize the temperatures even more, this morning I have increased the air flows in the LVEA from ~12,000 cfm per air handler to ~18,500 cfm. This has already made a considerable improvement and I will continue to monitor.

Everything appears to be "business as usual". There are very marginal downward trends in the osc pressures  and amp flow.

Laser Status:
SysStat is good
Front End Power is 35.89W (should be around 30 W)
HPO Output Power is 153.9W
Front End Watch is GREEN
HPO Watch is GREEN

PMC:
It has been locked 10 days, 18 hr 36 minutes (should be days/weeks)
Reflected power = 23.33Watts
Transmitted power = 48.29Watts
PowerSum = 71.62Watts.

FSS:
It has been locked for 0 days 4 hr and 47 min (should be days/weeks)
TPD[V] = 2.786V (min 0.9V)

ISS:
The diffracted power is around 2.7% (should be 3-5%)
Last saturation event was 5 days 23 hours and 10 minutes ago (should be days/weeks)

Possible Issues:
PMC reflected power is high

TITLE: 10/30 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    Wind: 17mph Gusts, 12mph 5min avg
    Primary useism: 0.06 μm/s
    Secondary useism: 0.28 μm/s
QUICK SUMMARY:

14:18 Kissel in early to do some more B&K hammering in HAM2

Members of the Stochastic Group have expressed interest in magnetic coupling for estimates of Schumann Resonance coupling during O2. Automated coupling functions for all injections are not quite ready to be posted at pem.ligo.org, so we are going ahead and posting site-wide magnetic coupling functions from the August 2017 PEM injections here.

Magnetic field injections were made at multiple locations in all 3 LVEA/VEAs and electronics rooms. The LHO injection locations are shown in the first figure below and the injection locations at LLO are similar. The code (started by Julia Kruk and completed by Philippe Nguyen) used the following procedure:

1) Coupling functions (meters of DARM per Tesla) were calculated for each magnetometer (the quadrature sum of the axes), for each of multiple injections in the local area (LVEA/VEA or electronics bay). The coupling function is the DARM signal divided by the magnetometer signal.

2) The coupling functions for each injection for each sensor were narrowed down to a single coupling function for each sensor by picking the minimum coupling factor at each frequency. Selecting the minimum coupling factor eliminates excessively high upper limit coupling factors for sensors that are far from the injection and coupling sites and thus detect small fields for large DARM signals.

3) For the site-wide maximum coupling function given here, the maximum coupling factor at each frequency is picked from the coupling factors for all of the sensors on the LHO/LLO site.

Of course, site coupling will be the combination of coupling at all coupling locations within each site - this is just the largest of these at each frequency. We think that the largest coupling factor is probably a fair estimate for the site because other coupling locations with lower couplings can increase or decrease the overall coupling. But the coupling functions here could be multiplied by a factor like sqrt(2) to be conservative.

Other issues:                                                                               

There was a large change in magnetic coupling during O2 at LHO, as noted in: https://dcc.ligo.org/DocDB/0144/G1701613/002/GenevaTalkSm.pdf , and we don’t know when it happened. I think that, as Schumann Resonance coupling becomes more important, we should probably push for a continuous magnetic injection at each station, like a calibration line, or at least weekly injections.  Back when our magnetic coupling was dominated by permanent magnets on the test masses, it didn’t change for years. But now we tend to be dominated by coupling to cables, and this can change dramatically as electronics and cables change. After talking with Richard M., my best guess is that the change happened May 16^th when the ITM ESD power supplies were changed, but that is just a guess. For S3 it might be a good idea to set up a single continuous line injection at the LHO corner station in order to better study coupling variation.

Another consideration for Schumann Resonances is the eddy current shielding due to the steel skin of the buildings. This is not included in these coupling functions because the injection was from within the building. We should measure this, but assuming it is the same as for a chamber, it would be about: 1/sqrt(1 + (f/20)^2), or a factor of 0.93 at 8 Hz and 0.55 at 60 Hz.

Philippe Nguyen, Julia Kruk, Anamaria Effler, Robert Schofield

J. Warner, S. Appert, T. Shaffer

We had some unexpected time to work on HAM2 baffles after some FedEx kerfluffles, so Jim and I went into HAM2 with some freshly baked parts and an engineer (just in case things got out of hand). This work went really fast with the three of us and we managed to finish up PRM, the last beard baffle, align all of the panels we needed to, and then torque and cap everything. I went into the beam tube to work from there and to be the eyes to align, and of course, I wiped on my way out.

We left the table baffle that sits in front of PR3 off the table for now, but with the mounts bolted down. This way the other crews that still need to do work have a little bit of space to work and won't scratch anything, hopefully. To place this last panel will take only a minute or two so we can easily do it after the major work is all done.

Pictures to come.