Nutsdinee, Elli
The power on the EY HWS was too high and was saturating the HWS camera. We replaced the mirror HWS-M4 on ISCTEY with a Newport 10B20NC.1 beam sampler, and dumped the transmitted beam.
Robert, Dave. WP5191
I modified all PEM models to use spare ADC channels for Robert's testing. At the end stations spare channels on the first ADC (ADC0) were fed into the PEM model. Since this is a lower ADC card than the one currently used, I replaced the current ADC0 part with ADC1, then added a new ADC0. The final configuration is ADC0=card0(the PCAL card), ADC1=card3(the PEM card). On the first ADC, PCAL is using channels 0-7 and 28-31. PEM is using channels 8-13
At the corner station things are easilier as PEM has three ADC cards and the last card has 11 spare channels (channels 21-30 were used)
All the new channels are acquired by the DAQ in both science and commissining frames at 2048Hz. The addition to the science frame is temporary pending a decision to permanently add them.
I have named the new channels H1:PEM-{loc}_ADC_{card}_{chan}_OUT_DQ where:
loc=EX,EY,CS
card= physical card number (starting at zero)
chan = channel number (starting at zero)
h1pemex, h1pemey, h1pemcs and the DAQ were restarted.
7:25 Richard and Peter to LVEA working on PSL UPS
7:48 Richard and Peter done
8:30 Fil and Andres to LVEA STS cabling
8:45 Craftsmen Cabinets on site
9:04 Joe D to LVEA for maintenance
9:06 Jim loading new isolation filters on ETMx ISI
9:14 Christina to both end stations
9:25 Fil and Andres out of LVEA
9:36 PSL team swapping chiller
9:47 Cris and Karen done at EY, going to EX
10:12 Joe D out
10:18 Cris and Karen done at EX
10:34 Nutsinee to LVEA near HAM 4 for HWS work
10:39 Elli and Nutsinee to EY for HWS work
10:50 Nutsinee out of LVEA
11:56 Hugh out of LVEA
12:33 Nutsinee to HAM4 for more HWS work
13:54 Elli to HAM4 HWS work
14:31 Hugh to beer garden for STS work
14:57 Hugh done
15:48 Greg and Elli to LVEA hunting parts
Elli, Nutsinee
Today we fine tuned the sled beam position on all optics, then get the green beam through both irises and hit the HWS. We moved the bottom periscope mirror back a little as the pitch knob ran out of room. We still don't see a decent return sled beam.
This is mostly to record something weird I saw after switching blends. I don't think the performance of the interferometer is affected. Take if for what you will.
I installed new isolation filters on ETMY today, and while watching the ISI to make sure the loops were stable I found something weird. At first I was worried that the ST1 Y loop was broken because the ISO output spectra was higher than X by an order of magnitude over ~40-150 hz, but then I realized the blends were different (X was using 45mhz, Y was using 90mhz). I switched the Y blend to 45mhz and the output dropped to the same level as X. When I switched Y back to 90mhz, after the blend switch completed ~20 seconds later a very unnatural "shelf" appeared in the output spectra ~200hz (mostly Y, but others too). This shelf raised the noise as it moved down, and stayed high after the shelf stopped visibly moving. I'm not clever enough to put a video together, but the 3 attached spectra show the story. The first is the shelf forming at ~200 hz, the second is the shelf moving down in frequency, the third is roughly when the shelf stopped moving. I watched the time series of the local sensors, supersensor and ISO out while this was happening but I saw nothing obvious.
During the week of April 20th, Danny, Gary and Giles joined Travis at the LHO Fiber Weld lab to perform a practice round of fiber welding. In part this was also to fire up the equipment and check functionality after a move around the site followed by long downtime.
Giles summarized the week well in an email to Norna:
Today we finished off welding/de-stressing and hanging the 2nd test hang. Everything went fine and probably around 1mrad pitch. We had put in some slightly thinner fibres as a test and these are probably d ~350um. We are going to profile a spare (we pulled 5 and used 4). So in the end, we did a total of 18 welds with 1 cutout. Certainly good training and important in order to keep up to date. Just looking to the future and spares, I think it will be essential to get some more gold mirrors, spare galvanometers/boards for both sites and an update of the profiler PC which is painfully slow. We also discussed some stress relief for galvanometer wires to reduce problems we had with wires coming loose.
Note - the galvanometer cable strain relief is currently underway by Fil/Travis.
Between yesterday and today, Gerardo and I (well mostly Gerardo, I just spot checked and helped with calculations) successfully bonded an ear onto the S3 flat of ETM11. The ear is s/n 188. By successfully, we mean that the surface area coverage and post-bond locational dimensions meet the spec.
We had an interesting find when we opened the optic can this morning, however. Upon dismantling the cake tin container from around the ETM11 as usual, we lifted the oring plate off of the AR surface and found one of the inner handle screws was left sitting upright on the surface of the optic. It must have spun loose during shipping and jostling around the lab. SYS/COC have been alerted to this failure mode of the container. This is the first optic we have started to process which has no first contact on it after long-term storage in the container. After carefully removing the screw, I inspected the area and miraculously could not find any macroscopic marks or scratches.
Following up on the loud wandering line around 1180Hz seen in the May 3rd lock (figure 1), we see this line in DARM as coherent with similar lines in SRCL, PRCL, MICH, IMC-I, IMC-F and PSL-FSS_TPD_DC_OUT_DQ. figure 2 shows the stamp-pem coherence matrix for the ~90 minutes of lock from 1114597337-1114600937 where each cell represents coherence for a single frequency and channel. The coherent channels are labeled in the plot.
In addition, representative cross-power spectrograms (where color represents STAMP SNR, effectively a measure of coherence) for an hour of data in this time for SRCL and PSL-FSS_TPD_DC_OUT_DQ can be seen in figures 3,4 that show the nature of this line. There is also a strong wandering line between 1150 and 1160 Hz that is seen in PSL-FSS_TPD_DC_OUT_DQ (PSD, figure 5) and that is also coherent in DARM (see figure 4). This line, however, is not obvious in the DARM PSD spectrograms.
These PSD and cross-power spectrograms were made using 60s ffts and coarse-graned to 1Hz frequency bins.
Each of PRCL, SRCL, and MICH also show coherence with the 1150Hz stationary line seen in DARM, while the IMC and PSL channels do not. See (18277) for a discussion of this line.
The Sensor was locked, moved, oriented, leveled, iglooized, on concrete, repowered and masses pushed. Looks like it needs another push (manual says many pushes are sometimes required.)
There was some evidence that part of the cabling could be the problem we are seeing with the HAM2 STS. This move will allow us to test the main house field cable. We can still check the Sat Box and Cable by exchanging them for the B unit which appears good with the newly overhauled PEM Vault unit. The Chassis can be check too, one step at a time.
The noise issue that has been troubling this machine is still with us--see attached. The noise is marked.
The Satellite Cable (orange) and Box have now been swapped (HAM2 & ITMY) to see if the noise shifts.
Another look after swapping the satellite box and cable has the problem still with the seismometer. I've now swapped (1615pdt) the signals going into the Interface Chassis. Will check after a time.
Because Hugh wanted to move STS-A into the biergarten to do a huddle test, I've switched the input HAMs (1-3) to running sensor correction with STS-C. This means all corner station seismic platforms are now running off the same seismometer, as the BSC's were also moved over to C when we substituted and evaluated the biergarten STS. Will probably run like this for at least the next couple of days.
At Kiwamu's request, I have updated his PD Null script, pdOffsetNull_ver2.py, located in opt/rtcds/userapps/release/lsc/h1/scripts, to include the balance of the LSC PDs. The list of PDs zeroed by this script is now:
'LSC-POPAIR_B_RF18',
'LSC-POP_A_RF9',
'LSC-POP_A_RF45',
'LSC-POPAIR_A_RF9',
'LSC-POPAIR_A_RF45',
'LSC-POPAIR_B_RF90',
'LSC-ASAIR_B_RF18',
'LSC-ASAIR_B_RF90',
'LSC-REFLAIR_A_RF9',
'LSC-REFLAIR_A_RF45',
'LSC-REFLAIR_B_RF27',
'LSC-REFLAIR_B_RF135',
'LSC-REFL_A_RF9',
'LSC-REFL_A_RF45',
'LSC-ASAIR_A_RF45'
'LSC-X_TR_A_LF',
'LSC-Y_TR_A_LF',
'LSC-TR_X_QPD_B_SUM',
'LSC-TR_Y_QPD_B_SUM',
'LSC-POP_A_LF',
'LSC-REFL_A_LF',
'LSC-POPAIR_A_LF',
'LSC-REFLAIR_A_LF',
'LSC-ASAIR_A_LF',
'LSC-POPAIR_B_LF',
'LSC-REFLAIR_B_LF',
'LSC-ASAIR_B_LF'
The changes have been committed to the SVN.
While looking over SDF Diffs after running the script, I noticed that the offset for ASAIR_B_RF18 (both I and Q) changed from ~0 to ~300 (a few order of magnitude), whereas the other PD offsets changed little. Just a heads up.
Sheila and I found that the dark offset for LSC-TR_X_QPD_B_SUM changed from −0.9 ct to −37.2 ct at 11:41:57 local this morning. Was this when the script was run? This value is way too big.
The nds2 channel scanner is failing because a channel (H1:TCS-ETMY_HWS_PV_UPPER_THRESHOLD) has a line-feed character appended to the name. This is being propagated into the frames and makeing any list of channels unreadable.
Nutsinee, Robert, Elli
We have temporarily switched the EY HWS to a different power supply to see if this will eliminate the 57Hz coupling into DARM. The HWS is currently powered using a cable running from the big transformer box at EY. The EY HWS is currently switched on, and can't be switched off remotely in this current configuration. We plan to returm the HWS to its orgininal power supply tonight or tomorrow morning.
I have updated the safe.snaps for PEM and OAF models. These systems now have greened SDF screens.
I have "greened" up the IOP models SDF settings.
New STS-2 cable has been pulled from the CER SEI racks to the PEM area in the Beer Garden. This is to help with the huddle testing of the STS-2's in the VLEA. Work areas included HAM4, BSC2, and BSC3 where the cable was dressed in the cable tray. Work started around 8:30 and ended around 9:30.
J. Kissel I've processed the DARM OLG TF measurement Evan and Sheila took last night (LHO aLOG 18269), and was dismayed to find that the DARM coupled cavity pole (DCCP) frequency has decayed back down to 270 [Hz]. This is obvious from the attached residuals, where I show two different versions of model parameters for last nights measurement compared against the two previous measurements taken during the mini-run, where the DCCP frequency was 355 [Hz] up near the expect value. I've again used a 0.99 coherence threshold, I trust this assessment of the DCCP frequency to within 2%, especially since that's the only thing I have to change in the model (besides the overall scale factor) to arrive at this conclusion (for the skeptics of my precision, see LHO aLOG 18213). What's going on here? --- Total Blind Speculation --- As Sheila mentions in the main entry (LHo aLOG 18264), the recycling gain and initial alignment had been restored to values during the mini-run. There has been quite a lot of work on SRC alignment: maybe those SRC loops which are now higher bandwidth -- though good for stable SRCL to DARM coupling (LHO aLOG 18273) are not so good for the DCCP frequency. Perhaps because they have some bad alignment offset? Perhaps we should try very slightly altering the DC alignment of these loops to see if it has an effect on the DCCP frequency, and then optimize for it. Eventually, one might imagine using the amplitude of either the PCal or DARM calibration lines as feedback to keep the pole frequency stationary and near the design value. The good news is that the overall scale factor (what we're assuming is either the optical gain or ESD driver strength variation) changed by less than 0.5%. --------------------- The measurement template has been copied over and committed to the CalSVN here: /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Measurements/DARMOLGTFs/2015-05-06_H1_DARM_OLGTF_LHOaLOG18269.xml The new model parameter set can be found committed here: /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Scripts/H1DARMparams_1114947467.m and as usual, the model is here: /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Scripts/H1DARMmodel_preER7.m and all residual comparisons are done here: /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Scripts/CompareDARMOLGTFs.m
I guess another possibility is some effect from the lower SRCL ugf. When the guardian goes into LSC_FF, the SRCL gain is reduced by 30% to reduce the amount of control noise appearing in DARM (the SRCL ugf goes from 50 Hz to 25 Hz). I'm assuming this reduction was not done during the minirun, when the good DARM pole was measured.
I suppose we should just run two DARM OLTFs in quick succession, one with the low ugf and one without.
Evan's idea seems unlikely: how could the SRCL loop, with a bandwidth of few tens of Hz, affect what happens at mich higher frequency? This would imply huge couplings of both DARM->SRCL and SRCL->DARM. Such lareg coupling should be easily visible when measuring the SRCL open loop gain.
The most likely hypothesis is that the pole frequency depends critically on the SRC alignment. One interesting test would be to inject two DARM lines, one at low frequency (50 Hz) and one at high frequency (1000 Hz) and track their variations while aligning the ITMs. We expect the low frequency to be constant (tracking the optical gain) and the high frequency to change (tracking the pole frequency).
We already inject calibration lines at 34.7 and 538.1 [Hz] which have been on since April 1 2015 (17621). They've been at a fixed amplitude that had been tuned for a 30 [Mpc] lock stretch, so the 34.7 [Hz] line may not be visible at all times, but still -- it's on the to-do list to make this comparison. Any off-site would be much appreciated!
