I increased the chilled water set point at the corner station chiller to 40 degrees F. Up from 36 degrees F.
Jenne, Stefan
- lowered CFSOF gain from 0.5 to 0.2. This avoids an instability due to gain peaking and possible radiation pressure feed-back at 2.15Hz.
- With that the coil driver switching was no longer an issue. In fact we reduced the ramp times all to 1 sec - it worked fine.
- We still keep dropping the sideband recycling gain and lost lock after ~36min. THus we decided to do some loop gain tracking.
- We added a laser frequency modulation line at 900Hz, and demodulated it in REFL_9_I (blue - LSC-LOCKINM_1_DEMOD_4_I) and REFL_45_I (brown - LSC-LOCKINM_1_DEMOD_3_I in the attached plot).
- Additionally we suspected that the BS ASC controls are going wacko. So we but pitch and yaw dither lines on the BS, and demodulated everything.
- Attached are two plots (with different time axis) of the result during a 50W lock.
Remarks:
- The REFL45 gain INCREASED by more than a factor of 2! This is consistent with less 45 sideband going into the cavity, and thus more being available as reference in REFL.
- The AS36_A gains seem to reflect that - i.e. a slight gain drop due to less 45MHz being available.
- The AS36_B gains initally agree, but then go completely nuts: AS36_B_Q_P (orange) keeps dropping, while AS36_B_Q_Y (red) turns around.
- Additionally, the AS36_B_Q_Y- Q dither demoduilation is growing significantly (not plotted). Not sure what to make of that. (the Q dither demodulation of all other signals remaind reasonable.)
Conclusion:
- We suspect that our lock losses might be due to the BS ASC signal becoming unsable. In addition, we have to carefully look at loop gains of all WFS that use 45MHz in REFL - their gain is expected to shoot way up.
- At lest for REFL ASC, it might be time to use the dynamic power normalization.
LEGEND for plot:
H1:LSC-LOCKIN_1_DEMOD_4_I_OUTPUT LSC: laser frequency to REFL_9_I (blue)
H1:LSC-POPAIR_B_RF18_I_NORM_MON 9MHz 2-f in PRC (green)
H1:LSC-LOCKIN_1_DEMOD_3_I_OUTPUT LSC: laser frequency to REFL_45_I (brown)
H1:ASC-ADS_PIT4_DEMOD_I_OUTPUT ASC: BS pit to AS36_A_Q_P (cyan)
H1:ASC-ADS_PIT5_DEMOD_I_OUTPUT ASC: BS pit to AS36_B_Q_P (orange)
H1:ASC-ADS_YAW4_DEMOD_I_OUTPUT ASC: BS yaw to AS36_A_Q_Y (purple)
H1:ASC-ADS_YAW5_DEMOD_I_OUTPUT ASC: BS yaw to AS36_B_Q_Y (red)
Beamsplitter motion as seen by its Optical Lever:
Over the course of the 40 minutes shown in Stefan's plots, the BS optical lever shows that it is moving:
I spent sume time lookin g at the signals form the AS36 diodes during this lock.
The 1st quation was whether all the RF from the length signals ios indeed in the I phase.
- Plot 1 shows the I sum and Q sum of AS_A_36. Most of the signal is in the I phase, but a phase change of -12deg (from -140 to -152 deg) would further improve the situation.
- Plot 2 shows the same thing for AS_B_36. It's overall phasing is as good as we can expect.
- Plot 3 shows the signal of all individual quadrants, I and Q (including the extra -12 deg in AS_A_36). Note that most signal is in quadrant 3. This might be an indication that we also have a centering issue, or it might be the result of an unhealthy about of higher order modes at the AS port.
- Plot 4 shows the Q signals that go into the BS error signals - they are a weighted sum of A and B - currently 0.666*A+1.0*B. For A the trace is plotted with (blue) and without (green) the extra -12deg of phase.
Note that the PIT signals (and to a lesser extend also the YAW signals) show a divergence to opposite direction, because their weighed sum is servod to zero. This is expected if one channel starts seeing more garbage than signal.
- Plot 5: This plot shows the BS dither line strength for PIT and YAW, for both A and B diode. Note that A is well behaved until the end, while B's gain increases significantly for yaw, and drops to almost zero for pit.
Based on plot 4 and 5 I suspect we would be better off using only AS_36_A at 50Watt. THe challenge will be it's offset - we will try this later tonight.
Jenne, Stefan, Terra, Jamie and Sheila commissioning. Peter and Jason finished work on the PSL at the beginning of the shift. Stefan started and I finished an initial alignment. Jenne and I had to change the fiber polarization in the MSR. We encountered issues with engaging the DRMI ASC loops again. This was mostly dealt with by stopping at LOCK_DRMI_1F and moving the optics to minimize the ASC error signals before engaging the control loops. The striptools for these are in /opt/rtcds/userapps/release/isc/h1/scripts. They are PITCH_ASC_ERROR_SIGNALS.stp and YAW_ASC_ERROR_SIGNALS.stp. There was a 300nm dust alarm in the PSL102 room. I trended the channel back and it appears to have happened a number of times before. I changed the ISI configuration from 'very windy' to 'windy'. 23:12 UTC Jenne to LVEA to measure noise of seismometer 23:18 UTC Jenne back Jason and Peter done in PSL, Stefan starting initial alignment 23:52 UTC Jenne and I changed polarization in MSR 00:11 UTC Initial alignment done 01:55 UTC PSL102 300NM dust alarm warning 03:16 UTC Changed ISI configuration from 'very windy' to 'windy'
Friday I had improved by a factor of 2x or so the persistent air leak in the Vertex RGA by torquing the suspect "factory" flange between the analyzer and it's protective nipple. This leak turned out to be only a small fraction of the total leak rate observed, i.e. there was more than one leak. Today I again removed all of the heat tapes and aluminum foil to gain access to the CF joints for additional helium leak testing. Note that all joints had been tested individually at various times prior to this most recent bake exercise as well as collectively via bagging the complete RGA assembly. Again, the joints tested good today so I decided to do a "fire hose" test and upped the flow of helium to "audible" values. John W. was physically present this time and his well documented aura was in full effect so we immediately found that the turbo vent valve was the culprit. This is consistent with all of the previous observations as the Turbo vent valve had not been sprayed in earlier hunts, the reasoning being that it is an O-ring seal with a very small cross section and permeates to the point of being a nuisance when leak hunting (normally!). Also, the rate at which is was leaking was just smaller than that which would show up on the foreline pressure gauge but just big enough for the portion that reverse flowed through the turbo stages could account for the value of observed leaking at the turbo inlet - Arrgghh!!!!! I took scans and decoupled the turbo and pump carts and shut all noise sources off. I'll make an entry tomorrow with the scan data.
Attached are the scans taken on 09-06-2016
No overfill required today as we had an LN2 delivery and I had to reduce the LLCV %open from 21% to 18%. ~1635 - 1700 hrs. local -> I visually confirmed that CP3's exhaust line was frosted - dewar vapor pressure at 20 psi. Next overfill to be Friday, Sept. 9th.
So I screwed up (I used to keep a tally of these occurrences but it has become too impractical)! It wasn't until after the LN2 delivery was underway (done?) that I realized that I hadn't proactively reduced CP3's LLCV %open value so as to avoid over pressuring CP3's LN2 reservoir. As I have now demonstrated, we are vulnerable to this on delivery days. Recall that while CP3 is in "Manual" fill mode, we have defeated any ability for CDS to close the Fill Valve (aka LLCV) as a response to overpressure. As such, we are completely reliant on Vacuum Personnel awareness. Gerardo suggested that I notify he and Chandra when LN2 deliveries get placed to lessen the likelihood of this happening again. John suggested that we leave open the exhaust check-valve bypass-valve and not rely on "Vacuum Personnel awareness" - that is why he gets paid the big bucks! I will open the bypass valve the next time I am at the Y-mid - Brilliant!
State of H1: PSL crew continue to work on plumbing - crystal chiller was filled in preparation for turning it back on
Additional Activities:
Sitewide:
State of systems that might effect H1 locking:
TJ, Jim
This afternoon TJ walked me through making a guardian node for the Compact BRS in the Biergarten. This BRS is only destined to be used for Newtonian Noise studies, but has been drifting a bit since install. Up to today, the monitoring system has been Krishna watching from off-site, then sending me an email when the PZTs go out of range, if I don't catch it before then. Now there is a guardian that monitors the PZT readouts and recenters them automatically.
This is not a critical node, so if CDS needs to kill the node for any reason, we can do that, but it's nice having BRS babysitting automated. I've added this node to the Guardian Overview, in the top right above the TCS nodes, but that screen is getting pretty busy. I've also added/commit the guardian code to the userapps/isi/h1/guardian repository.
The node has 3 states:
1. INIT which returns to RUN,
2. RUN which monitors the outputs to the PZTs and
3. RECENTER, which ramps off the damping, then the outputs of the PZTs, clears the histories of the PZT CTRL filters, ramps the CTRL gains on, then restores the damping and returns to RUN.
During today’s maintenance, I looked into a couple of peaks in DARM that have been present in recent weeks, even though we have been at low sensitivity. The peak at 56.8 is from the EX HWS. We should power it on a separate 18V supply like EY, or remember to shut it off for the O2 run. The peak at 451.5 was associated with Kyle's RGA bake-out pumping by HAM4, but I think he completed that today, so the peak should go away.
Re-Installed Common Mode Servo Board S1102626 for use with the mode cleaner. This is the unit that had problems when the filter board was installed 23 Aug. This unit has the 200kHz filter installed. Took advantage of the PSL work to fix the first channel on the DeMod board. This has been re-installed and the mode clean is again going through the first channel.
State of H1: PSL crew working on plumbing and flow sensors - taking lunch and will return to the PSL this afternoon
Maintenance Activities:
Current Activitiy:
I've collected the alignment changes in the IMC, the IMs (IM1-4), PRM, PR2, RM1, and RM2.
I've also included the senors that see the beams related to these optics, WFSA, WFSB, IM4 Trans, and ISS2 QPD.
WFSA and WFSB are plagued by a mirror in HAM2 that we believe is loose, because the signals ont he WFS jump when there's no indication of IMC mirrors jumping. Because of this feature in the WFS signals, I subtracted out the jumps from the segments of drift, and combined the drift segments to get a total drift over O1.
I've highlighted two sets of numbers:
I included RM1 and RM2 since they follow the change of the beam.
Most changed optics:
IMC WFS reflect the O1 input beam change in yaw of +33urad suggested in my alog 29463:
| change in O1 | |
| wfsa p | 0.055 |
| wfsa y | 0.254 |
| wfsb p | 0.210 |
| wfsb y | 0.359 |
Persuant to WP 6133, II 1150, FRS 4649 JimW & HughR
With the SEI completely deisolated, we lifted the platform with the HEPI payload springs. We addressed the Z and tilt dofs. The vertical drives on the Actuators were reduced substantially (8-6000 cts reduced to ~1200 or less.) Sadly, the horizontal drives increased albeit less than the verticals were reduced: a few hundred cts to 5000, 2000, 1500, & 900 cts. We would have addressed these too but Jim found Spring #4 (SE spring of SW pier) was feeling very galled. Will file an Integration Issue to track this Spring problem. Probably would need to remove the vertical actuator to access the Spring/XBeam Foot connection, but maybe we could get lucky.
The attached trends show the BS HEPI drives (OUTF ij OUTPUT) and the cartesian positions (..LOCATIONMON.) The unisolated positions (when the drives are 0) can be seen changing as we adjust the springs.
The next largest HEPI Drive is horizontal on the ITMY where 4000 to 5000 counts are holding a 300um +X offset remaining from Initial Alignment--II 1151, FRS 4650. After that, the BS Horiz, HAM1 Horiz, HAM2 and ETMX, if we care.
True, as long as HEPI is running fine, no big deal. And, unless we take all DOF errors out, IFO ops will not be possible without the HEPI Isolated. Would be nice to head to a state where, if we were to lose HEPI Pump Stations or a platform for a time, the position was such that IFO operations could continue.
Attached are long trends showing today's added ETM charge data. Note, Kissel switched the sign on the bias of both ETMs last week, but I only see it show up on the ETMX plot, and not the ETMy plot. That said, I have confirmed that the signs of the bias on the ETMs is as he now intends them to be as per his alog 29397.
The attached plot shows the atomic clock drift over the past 400 days. The current drift is about -6ns/day. The PPS monitors for the atomic clock were updated to a nominal value of -500ns (from 0ns).
FAMIS#6078
T240's
There are 6 T240 proof masses out of range ( > 0.3 [V] )!
ETMX T240 2 DOF X/U = -0.396 [V]
ETMX T240 2 DOF Y/V = -0.458 [V]
ETMY T240 1 DOF Y/V = -0.328 [V]
ITMX T240 1 DOF X/U = -0.338 [V]
ITMY T240 3 DOF X/U = -0.31 [V]
ITMY T240 3 DOF Z/W = -0.365 [V]
All other proof masses are within range ( < 0.3 [V] ):
ETMX T240 1 DOF X/U = 0.056 [V]
ETMX T240 1 DOF Y/V = 0.054 [V]
ETMX T240 1 DOF Z/W = 0.052 [V]
ETMX T240 2 DOF Z/W = -0.213 [V]
ETMX T240 3 DOF X/U = 0.008 [V]
ETMX T240 3 DOF Y/V = -0.033 [V]
ETMX T240 3 DOF Z/W = 0.039 [V]
ETMY T240 1 DOF X/U = -0.013 [V]
ETMY T240 1 DOF Z/W = 0.025 [V]
ETMY T240 2 DOF X/U = -0.12 [V]
ETMY T240 2 DOF Y/V = 0.039 [V]
ETMY T240 2 DOF Z/W = 0.022 [V]
ETMY T240 3 DOF X/U = 0.02 [V]
ETMY T240 3 DOF Y/V = -0.022 [V]
ETMY T240 3 DOF Z/W = 0.011 [V]
ITMX T240 1 DOF Y/V = 0.092 [V]
ITMX T240 1 DOF Z/W = 0.062 [V]
ITMX T240 2 DOF X/U = 0.078 [V]
ITMX T240 2 DOF Y/V = 0.083 [V]
ITMX T240 2 DOF Z/W = 0.071 [V]
ITMX T240 3 DOF X/U = -0.293 [V]
ITMX T240 3 DOF Y/V = 0.048 [V]
ITMX T240 3 DOF Z/W = 0.108 [V]
ITMY T240 1 DOF X/U = 0.029 [V]
ITMY T240 1 DOF Y/V = -0.033 [V]
ITMY T240 1 DOF Z/W = -0.163 [V]
ITMY T240 2 DOF X/U = 0.102 [V]
ITMY T240 2 DOF Y/V = 0.026 [V]
ITMY T240 2 DOF Z/W = 0.012 [V]
ITMY T240 3 DOF Y/V = 0.072 [V]
BS T240 1 DOF X/U = -0.058 [V]
BS T240 1 DOF Y/V = -0.011 [V]
BS T240 1 DOF Z/W = 0.056 [V]
BS T240 2 DOF X/U = 0.046 [V]
BS T240 2 DOF Y/V = 0.046 [V]
BS T240 2 DOF Z/W = 0.074 [V]
BS T240 3 DOF X/U = -0.123 [V]
BS T240 3 DOF Y/V = 0.037 [V]
BS T240 3 DOF Z/W = -0.106 [V]
STS's
2016-09-06 10:23:53.363517
All STSs prrof masses that within healthy range (< 2.0 [V]). Great!
Here's a list of how they're doing just in case you care:
STS A DOF X/U = 0.0 [V]
STS A DOF Y/V = -0.0 [V]
STS A DOF Z/W = -0.0 [V]
STS B DOF X/U = 0.117 [V]
STS B DOF Y/V = -1.252 [V]
STS B DOF Z/W = -0.251 [V]
STS C DOF X/U = -0.0 [V]
STS C DOF Y/V = -0.0 [V]
STS C DOF Z/W = -0.0 [V]
STS EX DOF X/U = -0.295 [V]
STS EX DOF Y/V = 0.561 [V]
STS EX DOF Z/W = 0.049 [V]
STS EY DOF X/U = 0.045 [V]
STS EY DOF Y/V = 0.33 [V]
STS EY DOF Z/W = 0.257 [V]
State of H1: PSL is down, PeterK is working on the cooling lines
Activities:
pre-15:00UTC(8:00AM local):
I had another look at the slow drop in sideband powers that consistently breaks lock within 20 minutes of powering up to 50 Watts.
This time I changed the soft loops to X,Y degrees of freedom (first I made the pitch filters for dsoft match csoft, this worked fine but isn't in the guardian). I ran dither lines on the test masses and tried to move offsets in the soft loops to keep the spot positions stable, but this didn't help the tanking sideband powers at all. I tried moving PR2/SR3/POP offsets. SR3 can help improve the AS90 build up after a PR2 move that helps POP18 but walking these together didn't work out well. I tried locking at 40 Watts where we have more time to move offsetsm but didn't find any alignments that could help the sideband build ups. We might have to look at some lensing. I tried using offsets in the POPX to PR3 loop, but as we expect these only made things worse.
The fastshutter lockloss checker seemed to think that the shutter had not fired in one lockloss today, but as shown in the attached screenshot, it did fire. Leaving the IFO with Kiwamu for the night.
On the fast shutter script:
I forgot to mention that I fixed a typo inthe LOCKLOSS_SHUTTER_CHECK yesterday. The arm power check looked at the x-arm power twice (instead of both arms, i.e. I changed line 26 from
if circ_power_x >=arm_power_upper_thresh or circ_power_x >=arm_power_upper_thresh:
to
if circ_power_x >=arm_power_upper_thresh or circ_power_y >=arm_power_upper_thresh:
and line 34 from
if circ_power_x < arm_power_lower_thresh or circ_power_x < arm_power_lower_thresh:
to
if circ_power_x < arm_power_lower_thresh or circ_power_y < arm_power_lower_thresh:
It looks like the checking script now sometimes triggers without the interferometer actually dropping lock - the Guardian time stamp on Sheila's plot does not agree with the actual lock-loss.
This probably happened because during the transition the Y arm fulfilled the HIGH_ARM_POWER criteria, while the X arm fulfilled the LOW_ARM_POWER criteria.
Thus I changed line 26 from an 'or' to and 'and'. This hsould properly latch the transition.
if circ_power_x >=arm_power_upper_thresh and circ_power_y >=arm_power_upper_thresh:
return 'HIGH_ARM_POWER'
The last 4 lock-losses (two from Sheila's two locks in INCREASE_POWER, and two of Stefan's lock in COIL_DRIVER_SLOW
Summary:
Filter configuration for ISS 1st loop to generate RIN channels (H1:PSL-ISS_PDA_REL_OUTPUT and PDB) doesn't look good. It seems as though we're somehow chosen to use inferior of the two filters in place both for "CALI_AC" and "CALI_DC", assuming that D1001998-V2 (PD circuit diagram) and D1001985-V2 (ISS circuit diagram) are correct.
I made somewhat better filter for "CALI_AC". For "Cali_DC" probably it's good enough to use the one we're not using. I loaded the coefficients for the new file for H1PSLISS from H1PSLISS_GDS_TP MEDM screen.
This doesn't affect the loop because these channels are not in the feedback loop, but making these filters right makes it easier for different RIN channels to be compared.
Details:
Reading D1001998-V2, D1001985-V2, T0900630, analog part of the monitor output for PSL-ISS_PDA and PSL-ISS_PDB ADC have analog z, p and k of [0.0723;2700;0.0707] Hz, [3.3607;130;3.12;2300] Hz, and 0.2, they're all in the PD box (ISS box is just the pass through as far as these outputs are concerned). These are DC coupled.
After they are received in the front end model, the signal is first converted to volts but not dewhitened by PSL-ISS_PDA, and then distributed to PSL-ISS_PDA_CALI_DC and PSL-ISS_PDA_CALI_AC. In DC the signal is low-passed, and in AC it's dewhitened and high-passed, and AC is devided by DC to give RIN (first attachment).
In CALI_DC path, there are two filters FM1 and FM2, only FM1 is used (second attachment left). I also plotted the inverse of the analog whitening transfer function including the DC gain in the same attachment. FM1 looks like a strange dewhite, nothing wrong with that, but I don't see any reason to prefer FM1 over FM2. Just use FM2.
In CALI_AC path, there are also two filters FM3 and FM4 (second attachment right). Compared with the inverse of the analog, it seems like the one in use (FM3) underestimates the RIN by 18dB at 1kHz. FM4 looks better but it's DC coupled. I made a new filter (green) and put it in FM5.
It's kind of odd that we're keeping DC gain factor in two different parts (CALI_DC and CAL_AC) instead of upstream. However, moving this gain into upstream affects PDASTAT thing (see the first attachment again), so I'll not fix this.
I have enabled the filters that Keita created/recommended. The attached screen shot shows the new settings for CALI_AC and CALI_DC for both PDs. Additionally, I changed the sign of CALI-ACs in order to make them consistent with CALI-DCs which had a minus sign in the gain field.
The SDF table is updated accordingly.
