As of now there are some bogus offsets on POP QPD sled output:
H1:ASC-POP_A_PIT_OFFSET = -0.03
H1:ASC-POP_A_YAW_OFFSET = +0.66
H1:ASC-POP_B_PIT_OFFSET = -0.72
H1:ASC-POP_B_PIT_OFFSET = +0.57
Turns out that people set these to remember the good alignment and then forgot.
08:00 LVEA is LASER HAZARD
08:15 ISS diffracted power was adjusted to 9.5% from 10.5%. refsignal=-2.06V
08:47 Aaron to X-end to re-terminate P-cal cables
08:48 Jeff B out to LVEA to take measurements in W Bay
09:06 Commisioning Reservation System is showing "Do Not Disturb the IFO" for another day, yet the Observation Intent Bit is not set to undisturbed.
09:15 Jeff B out of LVEA
09:30 Jeff B back in the LVEA
09:57 Travis to End-Y to take pictures around P-Cal viewports. Not touching anything.
09:57 Jim and Dave to end station(s) electronics rooms
10:00 Bubba working on coms from front gate
10:29 Karen goin to midY and End Y to clean
10:49 Travis is back from Y end and going to retrieve a viewport can from the LVEA to bring back to the Y End.
10:54 Dave an Jim have returned
11:24 Karen finished cleaning duties on Y Arm.
14:30 Richard out to the LVEA for a "minute"
14:36 Richard out of LVEA
Krishna had suggested that we could use an intermediate blend filter for the BSC (more aggressive than the 750mhz blends, less aggressive than the LLO blends), to take advantage of the sensor correction. At the SEI call today, it was suggested that we try the 01_28 blend being used on the HAMs, which is a ~250mhz blend. After a little hacking, I was able to get something that could be installed. All I had to do was make extra copies of the filters in a mat file and change some variable names, but it took a little while to figure that out. The blend routine was then able to compute the complementary filters for the T240 and L4C's. The X and Y blends for St2 look a little funny, they aren't quite complementary above the blend, but we don't need these filters for St2. See attached plots for complementary forms, St1 on the first page, St2 on the second page.
I won't install these new filters until next week, so I won't risk disrupting commissioners.
J. Kissel For the record, the design of sensor correction filter installed with which we hope to get improvement by increasing the blend frequency is detailed in SEI aLOG 594. Though this filter was originally designed for use in the Z DOF, it has been installed in the X direction on H1 ISI ETMX.
Our source at ERDF predicted that day shift and swing shift truck traffic today (10/17) would be light, but as of midday the 1-3Hz noise appears to be comparable to a regular (noisy) weekday. A crew will work at ERDF tomorrow, Saturday (~15 km from LHO), but there should be no hauling tomorrow.
no restarts reported. Day 2 of QFS memory upgrade.
Jim and Dave
We returned the 18bit-DAC AI chassis to EX after reversing the internal ribbon cables. We verified it was working with DC offsets on PEM channels, and then connected the standard DB9 cable from chn6 (counting from zero) AI to chn28-31AA. We verified that the Duotone loop back the h1calex model was outputting on DAC ch6 is seen on the ADC ch28.
We went to EY and outputted a DC level on ch0 using the PEM model, we verified it was coming out of the AI on ch0 using a scope. No need to open up EY chassis.
We did note that the EX chassis has a vented lid, while EY has a solid lid.
SEI - nothing to report
SUS - 3IFO ongoing/hold Betsy out
BRS - good
P Cal - pulling cables at end Y; re-terminating cables at End-X.
PSL - nothing to report
Commish - not much progress. Possibly a TCS issue hindering DRMI locking. More information in Sheila's A-Log (14492)
Facilities - HFD on site today to investigate an issue in the LSB building
I took the opportunity this morning to get the snap updated after doing the matrices yesterday 14380. ISI back under Guardian control.
We just turned off the CO2 laser. We had seen our contrast improve from 99.1% to 99.8% (after about 7 hours at 192 mW CO2 power), and finally after about 19 hours we measured the contrast at 99.6%. Dan has also measured the OMC mode matching, which seems to have gotten worse for ITMX (measured around 17 hours). In the few minutes since we turned it off, the contrast has improved again.
Today we have had considerable difficulty locking DRMI, beause of the mode hopping problems. There are many examples of short locks where the mode hopping seems to have killed the lock, some times are (all UTC, october 16th) 23:50, 23:23:50, 22:48, 22:26:27, 22:10, 20:44:20, 20:41:30, 20:36:04 and 20:34.....
Our difficulty today may or may not have been related to the TCS, it may just have been that our alingment was bad. We did have 2 longer locks, each about 20 minutes.
We decided to try locking PRMI, to see if we could get a better handle on alignment. I edited the PRMI guardian (in LSC configs) so now it is using the refl air PDs, and the gains are correct now that we are using the power scaling. (110 for MICH, 22 for PRCL) The distressing news is that now PRMI has a similar mode hopping behavoir to what we see in DRMI.
The first attached screen shot shows the way that our as camera has looked when mich was on a dark fringe most of the day today. The second one shows it about 7 minutes after we turned the laser off.
To sumarize the TCS story,
we turned on the CO2 laser for about 40 minutes at 1 Watt, realized we had overshot with the power, turned it off for about a half hour, durring which time our contrast improved. We then turned the laser on with about 0.15 Watt (according to Greg's rotation stage calibration) or 0.19 Watt (according to Alistair's power meter calibration). This should have been approximately right, and indeed after about 7 hours of this it seemed like our contrast had improved (from 99.1% with no TCS) to 99.8%. After about 19 hours of TCS we measured the contrast again, and it was about 99.6%. Dan also measured the mode matching from ITMX to the OMC. (since ITMY has better mode matching than ITMX with no TCS, we expected that the mode matching would improve if the contrast was improved.) Dan measurent indicated that the mode matching had gotten worse. We turned off the TCS after about 20 hours. This morning (about 10 hours after turning it off) Keita and I measured the contrast again; we got 99.6%. It seems like there is a lot of variablility in our measurements of the contrast.
The attached screen shot is an image of the as port with mich locked on the dark fringe, after TCS had been off 10 hours or so. This is what it normally looks like, for comparison to the pictures above.
The conculsion is that we don't really understand what happened when we turned on the TCS, and we are going to wait until we have hartmann sensors and a calibration to try it again.
K. Venkateswara
The tilt subtraction is working correctly now. The attached pdf shows the output of the tilt-subtracted super-sensor (in red) along with the GND_STS_X (in blue). The wind at EX is a measly 4-5 mph and in the wrong direction so there isn't much RY tilt. The red barely dips below the blue where the two sensors are coherent. It will be more apparent when the wind picks up a bit :)
Note that there are some odd features in the output of the filter above 7 Hz, which appear to be due to the low-frequency high pass filters, which foton doesn't like for some reason. I had to increase the high-pass frequencies to reduce this effect.
Also, note that most of what the STS is measuring below ~50 mHz is probably tilt but the tilt-subtraction isn't working well below ~20 mHz because we lose phase due to the high-pass filters and the finite d correction has not been implemented yet.
We will test this with the sensor correction next week when we get a chance.
To protect the OMCR QPD sled from pulse damage in case of the lock loss without working fast shutter (that is, once we're in full lock, see E1400405), OMC refl beam was misaligned from the sled in PIT.
5th pico mount for HAM6/ISCT5, which corresponds to one of the two pico mounts in front of the OMCR QPD sled, was moved in PIT by four magnum steps (+40000 counts).
Before: (X,Y)=(7900, -3402)
After: (X,Y)=(7900, 36598)
Before the move, the beam was more or less centered on the QPDs.
Note that the picomotor names for HAM6/ICST6 are messed up, and you cannot tell what is what from the MEDM screen nor H1:SYS-MOTION_C_PICO_C_CURRENT_NAME, according to Dan.
Pico 1 = AS A centering
Pico 2 = AS B centering
Pico 3 = AS C centering
Pico 4 = nothing
Pico 5 = Upstream(?) OMCR QPD sled pico
Pico 6 = Downstream(?) OMCR QPD sled pico
Took faraday analog scan of the Y-end at the request of others -> Data is useless (as expected) as the unbaked RGA (background) dominates the entire spectra. Note that the RGA is pumped only by the Y-end volume (i.e. the local pump cart is valved-out while the RGA is valved-in to the Y-end). A valid RGA scan was not attempted here as the setup time isn't justified (at this time).
Thanks Kyle.
AMU 20 and 22 (neon isotopes) certainly do not appear to be significant but as Kyle notes the RGA is too wet to say much else. After other priorities are dealt with the RGA will be baked. It is unknown when we can get around to this.
If neon were present we should expect to see both 20 and 22 at the ratio of the isotopes ( 90/9 ).
The amu 20 that we normally see in our systems is most likely doubly ionized argon(40). We have argon (and other air components) because of the large quantity of viton in our system which acts as an air reservoir. In addition the ion pumps do not pump argon or other noble gases very well.
I do not think there is much neon in the spectrum. The 20 peak looks like doubly ionized argon and there is not much at 22. The pressure of neon is less than 10^-10 torr, so if there is a leak it is less than 10^-7 torr liters/sec. Much too small to account for the reduction in overall pressure measurement in the pods. RW
Lowering the Electron Energy to 50eV should lower the rate of doubly ionized Argon without significantly decreasing the sensitivity to Neon. This is the setting we used in the Pod leak check, thanks to Rai's calculations.
9:16 Aaron and Filiberto to EX for PCal cabling
9:19 Hugh to electronics bay to rezero ground seismometer
9:46 Alsco onsite for Bubba
10:05 Jeff and Andres to LVEA for SUS storage box hunt
10:30 Jeff and Andres to EX and EY on continued storage box hunt
11:20 Kyle to LVEA retreiving vac parts
12:43 Fil and Aaron to EX
13:21 Krishna to EX
14:00 Jeff and Andres to MX for storage box
15:02 Kyle done @ EY
Notes for tomorrow's operator:
IP-01 Pump B is flashing red 'Not OK'. Kyle will investigate when available. Ignore for now.
HAM 6 DACKILL WD was tripped when my shift started this morning. I reset it. It tripped again at ~3:50pm. Reset again.
Replaced non functioning whitening chassis S1101631 with S1101602 on 10/15
Is this X end or something else?
It's X-End Keita.
Whitening chassis S1101631 was removed from the ISC-R1 rack this morning. Unit was found to have missing positive rail. Unit was replaced with new unit (Need to get serial number).
Serial number of new unit installed: S1101602
For the records, and in order for us to define new threshold values, I am posting here the pressure fluctuations for all the BSC-ISI pods (L4C, GS13 and T240), for all units on both sites (I will link this to the LLO log).
The first table attached shows the variations of pressure and the average leak rates for LHO. The L4C varies more than the GS13. The T240 pressure readout is pretty much the same than six months ago.
In this sample of data, we observe larger fluctuations at LLO than LHO, in all pods. The variations are however very similar within all the pods of a given chamber. So it is likely temperature related.
The last table compares the average variations and apparent leak rate for both sites.
Here are the HAM-ISI pods pressure. The comments made for the BSC-ISI pods hold for the HAM-ISI pods.
To summarize on this issue:
- We checked all pods on both sites. The trends are similar within the pods of a given chamber, so pods are likely not leaking. No pod show anornally low pressure (by comparison with other pods).
- John is looking into the RGAs to confirm there is actually no problem
- SEI is going to update the threshold parameters turning on the red lights
- DetChar is setting up automated monitoring
RGA scan posted at https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=14489
I'm leaving the interferometer with LSC feedback disabled, the the green lasers trying to lock to the arms. We are currently having both high winds and high microseism, so anyone who is interested in looking at the motion of our optics or performance of ISIs when the ground motion is high could use this time, starting at 23:39 UTC October 11.
I've left the intent bit as undisturbed, could the first person to come in and commision or work in the LVEA toggle it to commisioning?
Tuesday, October the 14th, was also a bad wind day, starting about noon. See Sheila's log 14475.
