at 10:37 PDT I restarted the DAQ in order to:
rsync with h1omc's ini file (following units typo correction)
temporarily remove H1EDCU_CONLOG from DAQ (while conlog is down)
use the latest Squeezer Beckhoff EDCU ini file (H1EDCU_ECATC1PLC4.ini)
The EDCU is now GREEN again, we should investigate if it turns RED.
While doing my usual Tuesday morning rounds of the PSL system, I noticed the crystal chiller was starting to get low on water. I added 150 mL of water; while this didn't quite top the chiller off, it got pretty close.
This morning I completed the weekly PSL FAMIS tasks.
HPO Pump Diode Current Adjust (FAMIS 8445)
With the ISS OFF, I adjusted the operating current of the HPO DBs. Changes are summarized in the below table; a screenshot of the PSL Beckhoff main screen is attached for future reference.
| Operating Current (A) | ||
| Old | New | |
| DB1 | 50.9 | 51.1 |
| DB2 | 53.3 | 53.5 |
| DB3 | 53.3 | 53.5 |
| DB4 | 53.3 | 53.5 |
I did not adjust the operating temperatures of the DBs. The HPO is now outputting 154.2 W and the ISS is back ON. The completes FAMIS 8445.
PSL Power Watchdog Reset (FAMIS 3673)
I reset both PSL power watchdogs at 16:23 UTC (9:23 PDT). This completes FAMIS 3673.
Attached is the updated trend of the HPO pump diode currents since we began adjusting the currents on a weekly basis. The flat spot in the beginning of September was a 2 week period of no adjustments as we swapped the NPRO laser in the 35W FE. To date, the currents are increasing linearly (minus the period in late May and early June when we swapped the failing DB1 for a spare).
Per request I repeated the burtrestore of the SUS alignment offsets done in alog 38730. patrick.thomas@zotws3:/ligo/cds/lho/h1/burt/2017/08/24/20:10$ burtwb -f h1ifoalignepics.snap I then zeroed the offsets for ITMX. The first image is a screenshot of the offsets before the burtrestore. The second image is a screenshot of the offsets after the burtrestore and zeroing ITMX.
Yesterday, prior to walking down the Y-beam manifold from in-chamber to inspect the Cryo baffle and alignment beams, Travis wiped some surfaces. When he wiped the Gate Valve 1 trough he picked up numerous macroscopic bits that I'd guess are viton from the o-ring which have shed during cycling. He also picked up what I will assume is black oxide (seems like what we've seen elsewhere). These surfaces haven't been touched in many years, so I'm not really surprised at these findings. See picture below.
This looks to me to be residual "carbon black" (MT N990) which is added to the Viton. It looks nasty but is benign from an (out-gassing) contamination point of view.
As a complement to Greg's aLog regarding checking the X arm cryopump baffle for interference, I checked the Y arm cryopump baffle while I was assessing ITMy pointing today. The clearances look even better than the X arm with several millimeters of clearance on both ECD blocks. See attached pics.
TITLE: 10/23 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC STATE of H1: Planned Engineering LOG: 15:42 - 19:29 UTC Jeff K. to LVEA to take in chamber violin mode measurments of ITMX 15:48 - 15:53 UTC Travis to bier garten to get 1st contact for Corey 16:27 - 17:47 UTC TJ to HAM5 to put target on SR3 16:32 - 17:53 UTC Jason to BSC1 to check the aux alignment laser assembly in front of ITMY 16:42 UTC Travis to bier garten to help Jeff K. with violin mode measurements 16:45 UTC Betsy to BSC1 to look at elliptical baffle alignment 16:50 UTC Chris to end Y chiller yard to check a filter 16:54 UTC Gerardo toggling PT124 off/on 18:02 UTC Kyle WP 7186 18:16 UTC Corey to optics lab to clean optics for tip/tilt 19:07 - 23:02 UTC Peter to optics lab 19:12 UTC Robert to LVEA to prep for BSC entry 19:13 UTC Chandra going for jog along X arm 19:29 UTC Jeff K. reports Travis and Betsy are back 19:44 - 19:52 UTC Jeff K. to CER to take pictures for Rolf 20:07 UTC Travis back to ITMX to continue violin mode measurements 20:30 UTC Betsy to BSC1, XBM, ITMY alignment 20:38 UTC Jeff K. back to ITMX to continue violin mode measurements 20:56 - 22:18 UTC TJ to table by HAM4 to rebag hardware 21:03 UTC Corey to cleaning area to grab flashlight 21:16 UTC Robert back for lunch 22:49 UTC Jeff K. back, reports Robert measuring elliptical baffle resonances, Betsy and Travis still in chamber
23:16 UTC Robert back
23:22 UTC Betsy and Travis back
J. Kissel, T. Sadecki Travis and I spend the day characterizing the violin modes of the new fibers on the new ITMX main chain, after confirming it was "mostly free" last week (see LHO aLOG 39111) with the same HeNe laser + QPD setup as described in LHO aLOG 38857. Processed data to come, but I'm building up quite the backlog... stay tuned, and thanks for your patience.
Processed data from the fully suspended measurements mentioned above are attached. Partially suspended data is from LHO aLOG 38965. Here're the results in tabular form, comparing partially suspended and fully suspended data, and their difference: Fiber S/N Harmonic Partially Fully df (F-P) +X / +Y S1400158 Fund. 502.45 502.422 -0.0281 2nd 994.8 994.188 -0.613 3rd 1463.8 1463.719 -0.0810 4th (1930.0) 1930.0 0.0 5th [2390.0] 2388.75 -1.25 6th No Data 2819.13 n/a -X / +Y S1400137 Fund. 503.96 503.891 -0.0694 2nd 997.85 997.484 -0.366 3rd 1468.3 1467.72 -0.581 4th 1931.6 1930.98 -0.616 5th (2391.0) 2390.50 -0.500 6th No Data 2858.44 n/a +X / -Y S1400154 Fund. 504.45 504.250 -0.200 2nd 1002.6 1002.36 -0.241 3rd 1466.6 1466.16 -0.444 4th 1936.4 1935.83 -0.572 5th 2390.0 2400.00 10.0 6th No Data 2856 n/a -X / -Y S1400164 Fund. 504.71 504.594 -0.116 2nd 1001.6 1001.25 -0.350 3rd 1472.4 1472.11 -0.291 4th 1940.3 1939.91 -0.394 5th 2408.3 2407.31 -0.987 6th No Data No Data n/a The resolution/uncertainty of the first four harmonics of fully suspended data is +/- 15.6 mHz, and that of the 5th and 6th is 62.5 mHz. However, the data in both partially and fully suspended cases show the Qs are particularly low so the above numbers have a grain of salt. With all of the above caveats, one can see there is a systematic shift in frequency downward from partially- to fully-suspended, with a mean and std of (F-P) = -0.31 +/- 0.22 Hz (ignoring the poor-data quality of the 5th harmonic). My impression from the Glasgow team is that this is expected, given the changes in boundary conditions that arise from suspending the PUM.
Last Friday I borrowed a controls/power extension cable on HAM1's pirani gauge, PT-100a, to test PT-120a, and thus cycled its power, which caused PT-124 to trip.
FRS 9278
B. Weaver, J. Oberling, T. Shaffer
This morning we took a quick look at the ITMy elliptical baffle (in BSC2) to get an idea of where its alignment is currently at before the baffle re-working currently scheduled for later this week. I set up and aligned the aux alignment laser assembly in front of ITMy, TJ moved the target assembly from PR3 to SR3 and we aligned the beam to it, and Betsy installed the elliptical baffle alignment target (D1102073). After this was complete we found that the ITMy elliptical baffle was almost perfectly aligned; the laser from the aux alignment assembly was centered on the crosshairs of the baffle target.
Betsy took several pictures and will post them as a comment to this alog.
The beam looks to be centered on the baffle target to within a mm (tol is many mm's). So, on we go with rebuilding it this week!
FAMIS 7461 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 3 days, 19 hr 37 minutes (should be days/weeks) Reflected power = 22.64Watts Transmitted power = 47.78Watts PowerSum = 70.43Watts. FSS: It has been locked for 0 days 16 hr and 19 min (should be days/weeks) TPD[V] = 2.789V (min 0.9V) ISS: The diffracted power is around 3.3% (should be 3-5%) Last saturation event was 3 days 9 hours and 1 minutes ago (should be days/weeks) Possible Issues: PMC reflected power is high
The laser may be turned on in the squeezer bay. This creates a laser hazard at height. 4 rails and a panel are in the oven and will be scanned today B&K measurements have been taken for all IMs Apollo will be back today to put AH1 into the new FMCS control system Corey will be replacing damaged black glass in HAM6 Corey will install an optic in a tip tilt suspension in HAM5 Corey will install viton on an OMC baffle GV6 may be closed today Robert wants to measure the resonances of the ITMX elliptical baffles
J. Kissel Looking particularly bendy, I also B&K hammered the newly installed HAM2-ISI table baffles (D1700335). Pictures attached. Processed results to come.
The PR3 lower baffle panel is not torqued down all the way yet because it still needs to be aligned. I was hoping to get all the alignment done at once for all the HAM2 baffles.
J. Kissel
I've created analysis scripts that take pre-measured DTT transfer functions of the OFI suspension and compares them against the model and previous measurements, similar to what's in place for all other suspension types. The new scripts live here:
/ligo/svncommon/SusSVN/sus/trunk/OFIS/Common/MatlabTools/
plotOFIS_dtttfs_M1.m << processes single DTT transfer function into a standard format, shows cross-coupling and EUL drived to OSEM sensed transfer functions
plotallofis_tfs_M1.m << compares as many measurements as possible against a standard model
The resulting plots are attached.
In summary -- still plenty of work to do to understand the actuated OFI!
Measurement Details:
The set transfer functions shown, 2017-10-13 (from LHO aLOG 39033), are with the eddy current damping magnets completely backed off, and the drive-chain is using that of OM1 (a 20 Vpp / 16 bit DAC, a HAM-A driver, AOSEMs for coils, and 3 DIA x 6 LEN [mm] magnets), and the sensing chain is as designed (AOSEM, US SatAmp, 16 bit / 40 Vpp ADC).
Calibration Details:
You'll note that the scale factors for the L-to-L and Y-to-Y measured transfer functions don't match the model. I think that the T-to-T TF matching the model is a coincidence. I'm confident I don't yet understand the electronics chain. I'm confident it's something in the electronics because the scale factor is the same above and below the resonance for each of the flawed model DOFs (and I've manipulated dynamical parameters and I have to change the parameters to non-sensical values to even come close to "fixing" the problem which doesn't help).
Here's what I do know:
(1) I have installed calibration filters into the OSEMINF banks of the OFI's sensing chain. These filters have the same gain we've been using for every OSEM since the beginning of time: 0.02333 [um/ct]. While this isn't necessarily accurate, given
(a) the use of the US satellite amp, which has a different transimpedance than the UK sat-amps (US = 150e3, UK = 121e3 [V/A]), and
(b) the UK sat-amps transimpedance gain has changed from 240e3 to 121e3 [V/A] since that number was originally calculated
so, we'll at most gain a factor of (240 / 150) = 1.6 with that correction, BUT -- that should be for all DOFs, so that screws up the T-to-T TFs.
(2) I *didn't,* at the time, have the individual sensors normalized to a "perfect" OSEM with open-light-current of 30000 [ct]. But, having just installed them now, this is at most a ~10% gain discrepancy between sensors.
(3) Though we don't yet have the complete calculation of the force coefficient of the AOSEM coil + 3x6 [mm] magnet combo a. la. T1000164, the only thing not-modeled is the slightly larger radius of the magnet. Thus, we can -- to-first-order -- scale the strength by the change in volume of the magnet as described on pg 4 of G1701519, hence I've used
forceCoeff_2x6 = 0.0309; % [N/A]; T1000164, T1400030, etc.
forceCoeff_3x6 = (3.0/2)^2 * forceCoeff_2x6; % [N/A]; G1701519 pg 4
forceCoeff_3x6
= 0.069525 [N/A]
(4) I'm *assuming* that OM1's HAM-A coil driver is using -v3 of the circuit, in which the output impedance is 1.2k (because of ECR E1201027), so the transconductance gain is 0.988 [mA/V], but I'm only 90% confident. It might be a -v2, and thus be 9.6 [mA/V], but then the data for the *actual* OM1 acceptance wouldn't match so well (e.g. see LHO aLOG 38260).
Model Details
This model matches the frequency and Q of the measured data quite well. I've tweaked the original model's parameter set (see LHO aLOG 12589) to better match the data. The following table describes the differences (remember, x = L, y = T, z = V):
Param ofisopt_damp ofisopt_h1susofi difference percent diff why change?
Unused global Eddy Current Damping Coefficient
'bd' [ 0.10898] [ 0.1] [ -0.0089822] '-8.24%' (just to see if the parameter does anything; it doesn't.)
Moments of Inertia
'I0x' [ 0.43968] [ 0.475] [ 0.035318] '8.03%' to move the yaw mode cross-coupling to match in the L-to-L TF
'I0y' [ 0.06499] [ 0.065] [ 9.676e-06] '0.0149%' (just rounded)
'I0z' [ 0.47101] [ 0.55] [ 0.078985] '16.8%' to lower the yaw mode frequency to match the Y-to-Y TF -- though many things can be manipulated to get this "right"
'I0xy' [0.00019696] [ 0.0002] [ 3.035e-06] '1.54%' (just rounded)
'I0yz' [-0.0066028] [-0.0066] [ 2.815e-06] '-0.0426%' (just rounded)
'I0zx' [ 0.002156] [ 0.002] [-0.00015597] '-7.23%' (just rounded)
Eddy Current damping Coefficients
'bx0' [ 5.0837] [ 3.5] [ -1.5837] '-31.2%' reduced to increase the Q to match the backed-off ECDs
'by0' [ 3.7] [ 2.5] [ -1.2] '-32.4%' reduced to increase the Q to match the backed-off ECDs
'bz0' [ 6.975] [ 7] [ 0.024974] '0.358%' (just to see if parameter affects TFs in question; they don't)
'byaw0' [ 0.47101] [ 0.1] [ -0.37101] '-78.8%' reduced to increase the Q to match the backed-off ECDs
'bpitch0' [ 0.06499] [ 0.06] [ -0.0049903] '-7.68%' (just to see if parameter affects TFs in question; they don't)
'broll0' [ 0.43968] [ 0.4] [ -0.039682] '-9.03%' (just to see if parameter affects TFs in question; they don't)
All other parameters (those based on physical dimensions) I've left as is.
Further -- it's still puzzling why the yaw frequency is so high. Original measurements gave a yaw frequency of ~0.4 Hz T1000109, yet both Mark and I show a measured resonance of ~1.039 Hz.
I believe I now understand the discrepancy between the yaw measurement made by Virginio Sannibale in T1000109 ( dated Jan 20th 2010) where he finds a value of yaw frequency of ~0.4 Hz (see section 3.4) and Jeff's recent measurement of yaw frequency of 1.0 Hz. The design of the attachment of the split clamp holding the wires at the tip of the blade was changed between when Virginio made his measurements and when the OFIs got installed. See D0900586, "Faraday Isolator Up Wire Assembly". In early designs (v1 to v4) the split clamp arrangement sat in a hole in the blade tip but was unconstrained in yaw (and vertical) except by friction/gravity. The design was changed in D0900586-v5 in 2013 as noted in the Notes and Changes where it states "Added item 10 cradle type clamp to clamp the split clamps to the blade." With the addition of the extra cradle type clamp the wire attachment to the blade is stiffened - thus increasing the yaw frequency. Verification of the change can be seen by comparing 1) Figure 1 in T1000109, where no cradle clamp is present, and 2) Third picture of OFI in tank in LHO alog 38999
Note that with a higher yaw frequency, the previous estimate of how much DC angle we might obtain is no longer valid. In G1701519 it was estimated that with 100mA in the AOSEM coils we might get ~490 microrad. Angle = torque/(I* w^2), where I - moment of inertia and w is the angular resonant frequency. w has now increased by 1/0.4. The moment of inertia from SW is ~0.47 which is slightly less than the value of 0.6 used in G1701519. Taking these two changes, a revised estimate for angle becomes 490 * (0.4/1)^2 * (0.6/0.47), i.e. ~100 microrad.