As was brought up at this afternoon's commissioning meeting, I have computed the test mass spot positions over the last year. T(0) on the plot is 10-Oct-2015, the date of the first A2L measurement that I have data for. The data through the end of O1 has been seen before, but I haven't looked at it since then. The spots have been moving a whole lot, so probably I should be better about updating these plots more often.
The 3 attached plots all show the same data, but with differing amounts of extra info. The dots are the spot positions, and the magenta horizontal line is the average position of all the measurements taken through O1.
The second plot adds to this a series of vertical lines of notable events, either for the IFO or for the alignment. The third plot is the same, but zoomed in to the last 75 days.
The lines are from the following "events":
You can see that after #7 many of our spot positions moved pretty significantly, although they continued to move after event 7 and I just didn't find / remember an event to explain this specifically. But, we'd been doing lots of alignment searching during that time. Also, after #11 when we went back to our July TCS and alignment values our spot positions largely went back to where they were before the big POP_A move. We could try more to get closer to the O1 spots, and that may be somewhat helpful. Food for thought.
The Hartman codes for both ITMs had been off for some days in order to upgrade the computer to Ubuntu 14. The new codes, which are written in python, were started at around 21:40 UTC today. No major issues so far. We did not check the Hartman beam alignment with respect to the cameras yet.
As Sheila pointed out, back in May we had a 25W lock that lasted >5h and never showed any indication of jitter peaks.
The attached plot 1 shows spectra from May 17 (25W), July 16 (40W) and Nov 3 (25W). Note that the May 17 spectrum is taken 4h into the lock.
Plot 2 shows inputy power and range of the May 17 lock.
Plot 3 shows all TCS settings of the May lock.
Plot 4 shows all TCS settings currently used.
Based on this, I would like to turn off the ITM ring heaters.
Yes, we should probably try this, and we will set them soon.
In the attached screenshot the red traces are from the short lock right before we turned on the ITM ring heaters on June 28th, the black traces are from a longer lock July 1st, and we do have worse noise at a few hundred Hz.
At this time we had the same ETM ring heater settings as now (1.5Watts on each), CO2X was at 0.4 Watts (we currently are at 0.2 but Kiwamu thinks it should be increased), and CO2Y was at 0.3W.
The HPO length locking servo is gain limited, and the error signal has coherence with down-stream sensors, including DARM. Decreasing the ILS gain increases the coherence with DARM at several peaks above 200Hz (see attached). We can't increase the gain much with the current servo shape (see 31121, servo board here), but a small gain increase reduces the coherence with DARM.
In the image: BLUE is low gain (servo gain 3.0 V), GREEN is nominal gain (servo gain 1.0 V), RED is max gain (servo gain 0.0 V)
- After the demod board was fixed, we could not transition to DRMI 3f. Stefan found that there was no 3f signal to transition to. He and Richard went out and disconnected/reconnected cables and it came back. - Evan changed something in the ALS guardian code that had to be fixed. - There was a 6.4 earthquake in Chile. - I ran through an initial alignment near the beginning of the shift. - Sheila told me that although there is less sensitivity to alignment in locking PRMI, there is currently something not quite right about the PRMI acquisition and we have a better chance of acquiring DRMI than PRMI now. - I tried to go from PRMI to DRMI, but guardian would not let me. Sheila said she has fixed this now. - We made it to NLN at 22:56 UTC. 15:07 UTC Robert to PSL enclosure to 'move hot things around'. 15:10 UTC Richard to PSL ISC racks 15:38 UTC Richard back. Demod chassis swapped with spare. 15:40 UTC Robert back 15:55 UTC Kyle to LVEA to take measurement with tape measure 16:08 UTC Kyle back 16:10 UTC Gerardo to LVEA to check ion pumps 16:14 UTC Peter to diode room to take inventory 16:17 UTC Robert and Richard to LVEA 16:23 UTC Richard and Robert back? 16:29 UTC Peter done 16:37 UTC Robert back 16:42 UTC Richard to LVEA to get Torque wrench Earthquake: 6.4 25km ESE of Curico, Chile 2016-11-04 16:20:43 (UTC) 16:53 UTC Richard to LVEA to swap back in original demod chassis 17:21 UTC Richard back 17:29 UTC Keita done zeroing dark offsets on LSC photodiodes 17:57 UTC Starting initial alignment 18:38 UTC Done initial alignment. SRC had trouble locking. 18:51 UTC Lost lock twice going to LOCK_DRMI_3F. Stopping at DRMI_ENGAGE_ASC. 21:14 UTC Sheila to LVEA 22:01 UTC Robert to end Y to pick up speaker from VEA 22:33 UTC Robert back
Took 6 minutes to overfill CP3, first set the manual fill to 36%, noticed the temperature drop slow, so I opened the valve a bit more, to 50%. See attached for more.
LLCV remains at 20%.
The demod chassis was fixed. One of the chips was not fully seated. Keita updated the dark offsets. I tried locking but had trouble on PRMI. I ran through an initial alignment. After that I lost lock twice in a row on the transition to LOCK_DRMI_3F. I stopped at DRMI_ENGAGE_ASC and Keita checked the phases related to the fixed chassis. He said they looked fine, but noticed that H1:LSC-REFLAIR_B_RF27_I_OFFSET and H1:LSC-REFLAIR_B_RF135_Q_OFFSET had been changed. He determined that they must be changed in guardian and asked me to find out where. I believe I have found the relevant code in ISC_DRMI.py under ZERO_3F_OFFSETS, but I'm not sure how to address it. The commissioners are in a meeting.
class ZERO_3F_OFFSETS(GuardState):
index = 110
request = True
@assert_mc_locked
@assert_drmi_locked
#@nodes.checker()
def main(self):
ezca.switch('LSC-SRCL1', 'OFFSET', 'OFF')
# Zero the 3f offsets
# [FIXME] either shorten the averaging or run the offsets in parallel,
# or both average the current offsets and put them in.
offsets = cdu.avg(5, ['LSC-REFLAIR_B_RF27_I_INMON',
'LSC-REFLAIR_B_RF27_Q_INMON',
'LSC-REFLAIR_B_RF135_I_INMON',
'LSC-REFLAIR_B_RF135_Q_INMON'],
)
# write offsets
ezca['LSC-REFLAIR_B_RF27_I_OFFSET'] = -round(offsets[0], 3)
ezca['LSC-REFLAIR_B_RF27_Q_OFFSET'] = -round(offsets[1], 3)
ezca['LSC-REFLAIR_B_RF135_I_OFFSET'] = -round(offsets[2], 3)
ezca['LSC-REFLAIR_B_RF135_Q_OFFSET'] = -round(offsets[3], 3)
@assert_mc_locked
@assert_drmi_locked
#@nodes.checker()
def run(self):
return True
From my understanding the problem was not with the guardian code, but that the INMON signals that were being averaged were bad and there was no DRMI 3f signal. Stefan and Richard went out and disconnected/reconnected cables and it came back.
This is a comparison between the ISS, ILS and PMC signals before (REF traces) and after the changes in the electroncis and the modulation depth, see 31095.
A few observations:
A better plot showing the relationship between the ILS and PMC mixer and HVMon signals.
Reducing the ILS gain by 16 dB increases the noise seen by the PMC by the same amount below 1 kHz. This change reduced the ILS ugf from ~10 kHz down to ~1 kHz.
The PMC PZT is decribed in alog 30729:
The ILS PZT is
Matt, Evan
As has been noted before, the DARM residual these days is usually microseism-dominated, and it is getting worse as we move into winter.
We installed a new boost (FM2 in DARM1) to give >40 dB more suppression at the microseism. The performance during yesterday's 25 W lock is shown in an attachment.
Tagging CAL.
Ryan and I were wondering why is there such a big difference in the residual OMC PD sum between L1 and H1. Both spectra are calibrated in mA so assuming similar optical gains the H1 DARM rms in meters is also 100 times higher than L1 (500 before the boost). This large residual DARM fringe motion may be responsible for the increased/incoherent H1 laser noise coupling.
We added a boost with resonant gain around 2 Hz. Now the residual is 7×10−3 mA rms below the bounce modes.
The DARM UGF is 70 Hz with 30° of phase.
Attached is a 60 day trend of PT140 which is a one of the new Inficon BPG402s? IP7 and IP8 have been a steady 5000 volts for this time period. Is this a gauge thing? I haven't been intimate with what Gerardo, John and Chandra have learned regarding the behavior of these new wide-range Bayard-Alpert/Pirani hybrids but this slope looks "not insignificant"
That slope looks really fishy. Are both IPs fully pumping? What does HAM6 pressure look like (also hot cathode ion gauge)? Did PT 170 and 180 flatten out after degassing?
We think that the pressure increase is due to temperature, see attached. aLOG noting temperature change.
Since we are talking temperature change in the LVEA, note the vertical change on some of the optics (BS and ITMs), other are affected as well.
I ran the current version of the calibration pipeline over a stretch of O1 data to reproduce the kappas and compare to those in the C02 frames. The filters file used was aligocalibration/trunk/Runs/O1/GDSFilters/H1DCS_1131419668.npz, as suggested by the calibration configuration page for O1: https://wiki.ligo.org/viewauth/Calibration/GDSCalibrationConfigurationsO1#LHO_AN2 The agreement looks quite good. Time series plots of the kappas and the cavity pole are attached. The start time used here was 2016-10-04 12:41:19 UTC (GPS 1127997696).
J. Kissel
Admiring the work of the SEI and ASC teams, we've just lost lock on a really impressive lock stretch in which we had ~40 mph winds, ~70th percentile microseism, and a 5.4 Mag earhtquake in the horn of Africa and survived. It would be most excellent it DetChar can compare amplitudes of ISC control signals, check out the beam rotation sensor tilt levels, the ISI platform sensor amplitudes, take a look at optical lever pitch and yaw compared with ASC signals etc.
Start: Oct 31 2016 16:15:05 UTC
End: 17:37-ish UTC
Winds and some ground BLRMS (showing microseism and the earthquake arrival) for this lock stretch. We survived at least one gust over 50mph before losing lock. No one changed seismic configuration during this time.
For the record, the units of the above attached trends (arranged in the same 4-panel format as the plot) are
([nm/s] RMS in band) [none]
([nm/s] RMS in band) [mph]
Thus,
- the earthquake band trend (H1:ISI-GND_STS_ITMY_Z_BLRMS_30M_100M) shows the 5.3 [mag] EQ peaked at 0.1 [um/s] RMS (in Z, in the corner station, between 30-100 [mHz]),
- the microseism (again in Z, in the corner station, H1:ISI-GND_STS_ITMY_Z_BLRMS_100M_300M) is averaging 0.25 [um/s] RMS between 100-300 [mHz] (which is roughly average, or 50th percentile -- see LHO aLOG 22995), and
- the wind speed (in the corner station) is beyond the 95th percentile (again, see LHO aLOG 22995) toward the end of this lock stretch, at 40-50 [mph].
Aside from Jordan Palamos' work in LHO aLOG 22995, also recall David McManus' work in LHO aLOG 27688, that -- instead of a side-by-side bar graph, shows a surface map. According to the cumulative surface map, with 50th percentile winds and 95th percentile winds, the duty cycle was ~30% in O1.
So, this lock stretch is not yet *inconsistent* with O1's duty cycle, but it sure as heck-fy looks promising.