Vern, Dave, Dwayne:
We disabled the old workpermit system and rolled out the new system during the 1pm Run Meeting today.
Links to the new system are available on the LHO CDS home page
The old work permit form is now a web page with links to the new form (see attached)
If you would like to subscribe to the mailing list wp-change-notices and get emails whenever a permit's status is changed, please email barker@ligo-wa.caltech.edu
CP3 log file DOES NOT exist! Starting CP4 fill. LLCV enabled. LLCV set to manual control. LLCV set to 70% open. Fill completed in 867 seconds. LLCV set back to 39.0% open.
see alog36588 for explanation
Per Chandra,
Increased CP4's LLCV %open value to 40%, up from 39% due to the amount of time it took to fill.
Fix, FRS 8248 https://services.ligo-la.caltech.edu/FRS/show_bug.cgi?id=8248 With Sheila's concurrence and oversight I installed a 6dB attenuator that was probably removed on 3/1/2017. Modified Beckhoff exceptable range so it was happy. Will accept change in SDF now.
CP3 and CP4 auto overfills are now programmed to run daily instead of thrice-weekly (Mon, Wed, Fri).
CP3:
Chandra requested that today's CP3 auto overfill not run. This has been taking out of the crontab until further notice.
CP4:
CP4 ran at 11:02 PDT with the new configuration: daily run, cut-off temperature lowered from -60C to -100C. The attached trend shows CP4 thermocouple second trend data for 20 minutes for the last three runs (Mon 5/29, Wed 5/31 and Thu 6/1).
This morning I changed the settings of the ALS laser that was removed from EndX (InnoLight Prometheus S/N 2011B).
The pump laser diodes temperatures were left alone.
- diode current 1.835 A
- laser crystal temperature 24.92 degC
- doubling crystal temperature 32.93 degC
With these settings the power at 532 nm was 48.7 mW. The power at 1064 nm was 1.54 W. The power was fairly
stable (+/- 0.1 mW) over a 2 hour period. Longer term monitoring should be done (ideally).
Crystal Chiller: Topped off with 125mL
Diode Chiller: Ed mentioned this was flashing red off/on, so it was borderline. I put in 200mL on Ed's suggestion.
Filters: White in color & free of debris
This closes FAMIS #6525.
I looked at the frequency stabilisation servo this morning. As it was the UGF was a bit low at ~185 kHz with a phase margin of ~35 deg (CG=16, FG=9). Raising CG to 22 increased the phase margin to ~48 deg but didn't quite put us where we would like to be. Dropping CG to 19 put the operating point to where we would like it to be. I took the opportunity to touch up the alignment into the reference cavity. The transmission signal went from ~2.7 to ~3.5. I restored CG to 16.
TITLE: 06/01 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Engineering
OUTGOING OPERATOR: N/A
CURRENT ENVIRONMENT:
Winds calm, primary and secondary uSeiem are calm
QUICK SUMMARY: ops lazy script isn't doing transition (-t).
TITLE: 05/31 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC STATE of H1: Planned Engineering INCOMING OPERATOR: None LOG: 23:21 UTC Dave offloading minute trends onto h1fw1 23:39 UTC Jenne using PZTs to coalign green onto IR at DC_READOUT 23:45 UTC Jenne done 00:19 UTC Starting initial alignment 00:46 UTC ALS X green falling off in initial alignment. Adjusting PR3 helped bring it back and increased the COMM beatnote. Moving BS to improve AS AIR flashes also helped. 01:15 UTC Initial alignment done Could not lock past DRMI 02:17 UTC Commissioners have left 02:17 UTC Kyle to mid Y 02:34 UTC Kyle back 02:59 UTC Kyle leaving for the night Leaving the IFO at DOWN.
[Kiwamu, Jenne, Vaishali]
Today we reset the green initial alignment setpoints (input laser pointing and ITM camera centroids) to match the SOFT offsets that we like at high power. Hopefully this makes locking more smooth, since the SOFT loops won't have to work very hard anymore.
We also chose new input matrix elements for the SRM ASC at high power. Kiwamu noted that AS36B was more responsive than AS36A (which is what we had been using), so we use mostly B with a little bit of A to get the total error point to be zero at the optimal SRM pointing. This is now in the guardian, although we haven't been able to relock to try running through the SRM_ASC_High_Power state. It should be fine though.
We lost lock at basically NomLowNoise when we closed the beam diverters. I'm not sure it was them - I think it was just time-coincident with a CSOFT pitch oscillation at 2.75Hz that came from my increase of the CSOFT Pit gain from 0.6 to 0.8 in an effort to squash the dP/dTheta instability. I think we need to get locked and measure the CSOFT loop to see if we can increase the gain at all, although it looks like the more promising plan might be to re-engage the ISS 3rd loop. We'll think on this more tomorrow.
Right now we're having trouble holding the IFO on ALS. Both Ed and Patrick noticed that the FSS is oscillating pretty regularly, and they're concerned that it's what is causing our locklosses. Peter and Jason, can you please take a look at the FSS in the morning?
We have reason to believe that CP3 is fixed and the ice blockage is gone. However, there was an auto overfill today at 11 am which may be skewing the reading, so we will let things settle overnight. Reservoir level reading is 100% on Beckhoff (software limit) and 120% on Magnehelic. Today we found the sensing line valves open to transducer, along with the valve that isolates them from each other, so we have been flowing much of the GN2 straight out the exhaust. Kyle checked these valves last night and thought the isolation valve was closed, but turns out it was just sticky and actually open.
We connected GN2 to CP4 sensing line, and will leave it connected for days vs. hours this time (readout on MEDM falsely shows 100% full). The flow is essentially zero right now, but set to 2 LPM in case it does open up. Isolation valve between two sensing lines is closed.
We are leaving CP3 LLCV in manual mode tonight.
1915 - 1930 hrs. local I had to convince myself (again) that we don't still have residual LN2 from today's overfill trapped between the current/former sensing line blockage and the, now closed, exhaust path. Since the valve separating the exhaust sensing line from the bottom draw sensing line (a.k.a. the low pressure line vs. high pressure line) was open during today's overfill and the fact that the pump's exhaust line is at the highest elevation, it is conceivable that the sensing lines are filled with LN2 during an overfill. If so, then following an overfill, if this valve gets closed, as happened today, LN2 could be trapped with no exhaust path as it converts to GN2. The resulting pressure would "test" the bi-braze joint and blockage. There could be LN2 still in the portion of the sensing line within the vacuum vessel even though the external-to-vacuum portion of the line is "warm" and having no frost. So, I (again) opened this valve to provide a path to atmosphere but observed no evidence that there was any pressure release or flow (I really do need to make some friends and to "get a life"). For CP4 the 1/4 polyflo tubing and acrylic rotometer effectively provide pressure relief as they would split long before the bi-braze joint. For CP3, I left the magnahelic differential pressure gauge valved in and it should fail in such a way as to relieve any extreme pressure long before the bi-braze joint. 0800 - Leaving site (again)
TITLE: 05/31 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: Ed
CURRENT ENVIRONMENT:
Wind: 11mph Gusts, 9mph 5min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.07 μm/s
QUICK SUMMARY:
Jenne, Kiwamu, Vaishali, Jeff K, relocking.
TITLE: 05/31 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Patrick
SHIFT SUMMARY:
LOG:
Performed a quick check of the ALS laser that was removed from EndX yesterday, InnoLight Prometheus S/N 2011B. The datasheet for this laser is here. The following settings were as I found the laser:diode current 1.832 A laser crystal temperature 29.02 degC doubling crystal temperature 33.41 degC diode 1 temperature 20.99 degC diode 2 temperature 20.30 degCThe output power at 532 nm was 47.4 mW as measured by a Thorlabs S140C power meter. The output power at 1064 nm was 1.53 W as measured by a Gentec TPM300 power meter. Initially the power at 532 nm seemed reasonably stable. Then I observed it climb from 47.4 mW to ~60 mW and back down a couple of times. During these episodes the 1064 nm power remained stable. The frequency doubling crystal TEC error signal varied from 1 mV to 2.2 mV. Which corresponds to a temperature change of 1.2 mV / (10 V/degC) = 0.12E-3 degC. The change in wavelength with respect to temperature is ~0.03 nm/degC. However just because the wavelength changes doesn't necessarily mean the output power changes, that depends on the resonator finesse. I then set the laser settings to those listed in the datasheet, namelydiode current 1.750 A laser crystal temperature 24.00 degC doubling crystal temperature 33.20 degC diode 1 temperature 20.99 degC diode 2 temperature 20.31 degCAt these settings the output power at 1064 nm was 1.44 W. Initially the output power at 532 nm was 41.4 mW but was seen to vary as high as ~63 mW. Again no temperature or diode power related signals appeared to vary in sync with the observed power changes. Perhaps of note is the thermistor reference voltage(s) were measured to be 6.64 V and 6.58 V, instead of 6.85 V for both the frequency doubling crystal and diode 2 respectively. Without knowing the circuitry for the thermistor, I don't know if this is significant or not.
Last week we took advantage of the down time to do Z diagonalization measurements on the BSC ISI's, as Jeff outlined in his alog 36360. I used the data we got to calculate and install coefficients on all of the chambers that needed decoupling. The first five plots are the closeout Z to X/Y transfer functions comparing the before and after results showing the reduced coupling via tilt from Z drive to X/Y motion seen by the St1 T240s. For these plots, blue is always before, red is the after measurement. I forgot to include Y units but they are in nm/s / nm*rthz because I didn't convert the T240 signal to displacement.
Yesterday I looked at repeating this on the output HAM's, I was just efficient enough to get HAM4 mostly done, but I need more time finish HAMs 2,3,5,6. The last attached plot is the Z to X/Y plots before and after for HAM4. The magnitude plots are in nm / nm*rthz. I also got data for HAM4 Y to RX, but it looks like the ISI is good enough in that DOF. HAM5 was similarly clean for Z to RX/RY, and I have a coefficient calculated for HAM6 Z to RX, but I would like to do a measurement after installing the cpsalign elements before I make a permanent change.
The measurements for the HAMs are essentially the same as the BSCs, driving at the inputs to isolation banks while the ISI is isolated with high blends (750mhz for the HAMs) with sensor correction off. Drives are usually 1-5e7 in awggui, for as long as you have patience for.
For the record, and to be explicit for future reference, here're the BSC-ISI ST1 tilt decoupling matrix elements (H1:ISI-${CHAMBER}_ST1_CPSALIGN_${M}_${N}) that Jim has now installed. One reads the matrix as "The corrected RX and RY CPS signals used in the isolation loops contain small portions of X, Y, and Z signals."
ETMX misaligned
X Y Z
a
l X 1 0 0
i Y 0 1 0
g Z 0 0 1
n RX -0.0030 -0.0020 +0.0060
e RY +0.0013 +0.0001 -0.0025
d RZ 0 0 0
ETMY misaligned
X Y Z
a
l X 1 0 0
i Y 0 1 0
g Z 0 0 1
n RX +0.0010 -0.0010 0
e RY +0.0005 +0.00075 0
d RZ 0 0 0
ITMX misaligned
X Y Z
a
l X 1 0 0
i Y 0 1 0
g Z 0 0 1
n RX +0.0015 -0.0025 0
e RY +0.0015 +0.0015 +0.0025
d RZ 0 0 0
ITMY misaligned
X Y Z
a
l X 1 0 0
i Y 0 1 0
g Z 0 0 1
n RX +0.0015 -0.0007 -0.0057
e RY +0.00075 +0.0005 +0.0030
d RZ 0 0 0
BS misaligned
X Y Z
a
l X 1 0 0
i Y 0 1 0
g Z 0 0 1
n RX -0.0001 -0.0007 -0.0035
e RY +0.00075 0 +0.0025
d RZ 0 0 0
WP 6652
ERC 170062
The BRS ion pump read back signals are now tied into the vacuum rack. Field cabling from each controller was pulled to connector header H (Pins 37-40) inside the vacuum rack. The Vacuum Controls Chassis was modified to add the new read back signals to terminal 15. Channel 1 is the voltage read back and channel 2 is the pressure read back.
Controllers for the BRS ion pumps are not the same.
End Y - Gamma SPCe controller
End X - MiniVAC Controller
F. Clara, G. Moreno, R. McCarthy, P. Thomas
(Krishna V., Gerardo M.)
Information for both systems:
BRS-Y
- ion pump is a TiTan 10SW from Gamma Vacuum (PN:10SWCV2HSCNN).
- the controller is a SPCe from Gamma Vacuum (PN:SPC1PS1U1ESNA).
- for the high voltage connection the system uses a SAFECONN type of cable/connectors.
- HV polarity is + (positive)
BRS-X
- ion pump is an old Varian 10 l/s pump.
- the controller is a MiniVac from Varian (PN:EX9290191)
- for the high voltage connection the system uses a FISHER type of cable/connectors.
- HV polarity is - (negative)