SEI
nothing planned

SUS
nothing planned

CDS
continue preparations for chassis swap
possible RCG upgrade on Tuesday

FAC
starting repair of wall around patio area
wet paint all around building
expecting delivery from Sunbelt

PSL
trips appear to all be related to flow sensor

VAC
preparation for vent of end stations in June
need to run pump cart at Y end for 24 hours to bakeout RGA, possibly Tuesday

This morning AOM diffracted power was up to ~ 13% with a refsignal setting of -2.00 . I've adjusted the Diff power to ~ 8.5% -> refsignal = -2.05

Summary

Today I wanted to see if increasing the bandwidth of the SRC ASC loops could make the 90 Hz SRCL coupling into DARM go away or become more stationary. I cranked up the bandwidth of the AS_C loop, but saw no improvement. We should try cranking further, or else try cranking the bandwidth on the AS36I loop.

Details

I was able to bring the interferometer to dc readout at 10 W with a recycling gain of 39 W/W. To get there, I had to turn on the ITM oplev damping again to avoid 0.4 Hz instability during power-up (and sometimes during the last steps of the CARM reduction sequence). I was able to engage the MICH, SRCL, and dETM yaw boosts without issue.

Then I tried increasing the bandwidth of the AS_C pointing loops. I was able to increase the gain by a factor of 30 just fine (2 ct/ct to 60 ct/ct, pitch and yaw), which gave a ugf of about 250 mHz as measured by step response. This means that the original bandwidth was less than 10 mHz, since the loop is 1/f below the suspension resonances. Correspondingly, the low-frequency angular motion seen by AS_C is suppressed by a factor of 30 or so, and the rms angular motion seen by AS_C is reduced by a factor of 4 in pitch and some small factor in yaw. Based on the attached spectra, it seems like we would have to push the bandwidth up to several hertz in order to see any further improvement in the rms. Anyway, after doing this I did not see any improvement in the stationarity of the SRCL coupling aroung 90 Hz.

I attempted to repeat this exercise with the AS36I loops, since Gabriele had previously found that the pitch loop was the dominant signal modulating the SRCL/DARM coupling once dETM yaw was adequately suppressed. However, I could not increase the loop gains by more than a factor of 4 before they went unstable (this was the case even when I engaged the same HSTS compensation filter as used for the AS_C loops). This factor of 4 was not enough to give a noticeable improvement in the spectra of AS36I pitch and yaw, since these loops are also slow (<100 mHz, just based on watching the loops' responses to transients).

I came in and found the PSL had tripped about 6 hours ago. It is again correlated with some flipping of the diode chiller flow monitor bit. After the trip, the bit flips for about 40 s before returning to the OK (1) state.

When I went to reset it, both chillers were on. The diode chiller has been holding steady at 20.5 lpm or so for the past hour (not sure about further back in time).

To answer Jeff's question about the wind, I looked at the ten hour lock, and the three hour lock starting about 23:30 UTC (ignoring the stochastic injection). I wrote a custom script to make the plots, since I couldn't get sensemon range from NDS. I've done a 3-minute median filter on the wind and range minute trends to smooth them out a bit.

The first plot shows the wind and range for the first lock. Around 12:30 UTC, the spectrogram (second plot) shows a big increase in the noise, and there's a corresponding decrease in the range. I think this is unrelated to the wind, and will be investigated elsewhere, so I've cut this lock off about 320 minutes in (third plot). The fourth plot is the scatter of the wind versus the range. A simple fit gives a value of 8.4 Mpc at zero with an 0.03 Mpc decrease per MPH of wind. The fifth and sixth plots are this repeated for the other lock, starting after the stochastic injection ends. The fit is 9.0 Mpc at zero with an 0.01 Mpc decrease per Mpc of wind.

I've attched the script I used. It needs a cache file for data of type H-SenseMonitor_CAL_H1_M called snsw.lcf. There's some values hard-coded, but it should be obvious what to change.

16:24 Jim left the interferometer locked. Intent bit switched to Undisturbed.

19:48 Lock loss. PSL tripped ("Epics Alarm" went red). The guardian didn't switch off the undistrubed intent bit. I switched it off few minutes later.

20:40 PSL recovered (Thank you Peter K!) but IMC wasn't. I waited at least 5 minutes but it doesn't seem to lock itself. I trended and adjusted the MC1, MC2, and MC3 pitch back to where it was before it lost lock.

21:22 IMC locked. Redid initial alignment for the first time today.

22:18 Locked at LOWNOISE_ESD_ETMY (~11Mpc)

22:28 Intent bit switched to Undisturbed

22:50 Undistrubed intent bit turned off. Attempted to damp the violine modes.

22:55 Intent bit switched to Undistrubed. Jeff Kissel suggested I leave the violin modes alone.

23:01 Lock loss. PSL tripped AGAIN ("Interlock OK" went red).

23:09 PSL recovered

23:47 I realigned IMC again. It seems to me that IMC optics read off the bad alingment from somewhere and didn't go back to where it was when the ifo was locked. I was able to bring the IMC reflected light down to 52 counts (It was 53 during the previous lock). The alignment is saved. AS Air flashing at none 0,0 mode. Redid the initial alignment (didn't take too long. The ALS was already good).

           ALIGN_IFO stays on MICH_DARK_LOCKED for a very long time even though AS AIR was ~0. I moved on to SRC ALIGN before the panel was green.

00:17 Lock loss at ANALOG_CARM. IMC locked itself this time.

00:34 Locking again at LOWNOISE_ESD_ETMY (~10 Mpc). Intent bit switched to Undisturbed. Leaving the interferometer at this state. Wind slowly picking up speed.

A few notes before I leave the chair:

- As Jeff K. has requested, it would be nice if a Detcharian out there could plot the BNS inspiral range vs. wind speed during lock segments. I'm unable to do ligo-proxy-init from the control room computer and don't know of other way to get the BNS range data.

- Guardian does not switch off the Undisturbed intent bit when lock lost.

- IMC lock does not recover on its own after both PSL trips, but recovered just fine after a lock loss that doesn't cause by a PSL trips.

- We have a total lock time of ~20 hours during this 40-hour mini run (started Friday 8AM, ended Sunday at midnight - locking 50% of the time). 

I guess that is it for the Mini run. Enjoy the data!

Since the initial alignment hasn't been done since last night. I'm redoing the initial alignment. Wind speed looks good so hopefully I can get it back up again soon.

J. Kissel

Having processed the last two DARM open loop gains -- the first measurements out to 5 [kHz], and the first measurements after we've tuned up the ASC loops to give us a consistent recycling gain of 35-40 -- I can now make the following statements:
- The DARM Coupled Cavity Pole (CCP) frequency is now consistently much closer to the "as designed" value. The measurements are consistent with a model of the DARM loop using a CCP of 355 [Hz].
- The ETMY ESD's driver pole frequency is 2.2 [kHz], not the colloquially thrown about 2 [kHz].
- I've added the violin modes to the model of the QUAD suspension, and they have no appreciable effect, but I'll leave them in for completeness.

On what these measurements and changes to the model mean for the uncertainty (precision and accuracy):
- The modeled unknown time delay remains at 0 +/- 5 [us].
- The frequency dependent uncertainty in the calibration model remains at +/- 2.5% in magnitude and 1 [deg], but I've data to back up that this extends out to the entire required* frequency band 10 and 2000 [Hz]. See attachment 2015-05-02_FittedCCP_H1DARMOLGTF.pdf (* OK, what *used* to be the requirement. The requirements are now extended albiet inflated out to 5 [kHz]; see T1300950)
- Over these last two measurements, the scale factor used to match the model against measurement has only varied by 3%. Indeed, if you cluster the eight measurements, grouping by CCP, then the standard deviations of the three, three, and two measurements are 7%, 41%, and 3%. However, the total standard deviation of all measurements is 22%, and the latter two measurements are only 1 day apart. From the data I have, I'm still not confident in decreasing the scale-factor uncertainty below 22%; perhaps PCAL can make a better statement on this (but I fear the current Mini-Run noise is too high for the low-frequency PCAL line). See 
2015-05-02_upto5kHzOnly_FittedCCP_H1DARMOLGTF.pdf
- The current calibration installed in the CAL-CS model is incorrect, both in frequency dependence and scale factor. 
    - Frequency dependence: The CAL-CS filters assume a DARM CCP of 389 [Hz] in the sensing path, and an ESD Driver Pole (ESDP) of 2.2 [kHz] in the actuation path. For the latest lock stretches, that inflates the uncertainty of CAL-DELTAL_EXTERNAL_DQ with a known, systematic error of 
      current / correct = ( 1 / (current CCP / correct CCP) + (current ESDP / correct ESDP) ) / (properly normalized)
                        = ( 1/zpk(-2*pi*389,-2*pi*355,355/389) + zpk(-2*pi*2e3,-2*pi*2.2e3,2.2e3/2e3) ) / 2
      which translates to as much as a 7% magnitude error at 1 [kHz], and 1.8 [deg] swing in phase surrounding 1 [kHz].
      This is demonstrated in 2015-05-02_H1CAL-CS_Systematic.pdf,
      This is also reflected in the statistical uncertainty estimate. All comparisons are shown if a 389 Hz CCP and 2 kHz ESDP were used in 2015-05-02_389HzCCP_2p0kHzESDPole_H1DARMOLGTF.pdf.
    - Scale Factor: this depends on whether we want to use 22% or 3% for our scale factor uncertainty. If 22%, then the last two lock stretches still fall within the 1.1e6 +/ 22% [ct/m]. But, if the scale factor is 1.2725e6 (the mean of the last two scale factors), then that indeed falls outside of 1.1e6 +/-3%
    - We *still* have not implemented any compensation for the analog or digital, AA or AI filters. 
- The GDS/DMT produced calibration is off just as much as the CAL-CS produced calibration, because GDS/DMT calibration is using the same filters.

------------------
All parameter files have been committed (with updated ESD driver poles, and fitted DARM coupled cavity poles) here:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Scripts/
H1DARMparams_1109994128.m
H1DARMparams_1111998876.m
H1DARMparams_1112399129.m
H1DARMparams_1112933759.m
H1DARMparams_1112942996.m
H1DARMparams_1113119652.m
H1DARMparams_1114541595.m
H1DARMparams_1114634170.m

Which are processed by the DARM model function here:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Scripts/H1DARMmodel_preER7.m

And then compared with the script here:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Scripts/CompareDARMOLGTFs.m

J. Kissel, E. Daw

In this current lock stretch, I've begun Ed's Stochastic Injection (LHO aLOG 18161) starting at 23:29 UTC. Scared of breaking the lock, I've started with multiplying the whole injection by a scale factor of 0.1. Out of habit, this has gone through the H1:CAL-INJ_TRANSIENT bank instead of the H1:CAL-INJ_CW bank, but signals arising from both banks should result in identical DARM CTRL [ct]. It should last ~10 minutes. The observation intent bit is on.

J. Kissel,

Early signs from yesterday's measurement: The DARM coupled cavity pole is now up at 355 [Hz], much closer to the designed/ideal/predicted LLO value of 389 [Hz] (LLO aLOG 15923). Hopefully it stays consistent with today's measurement (or is higher!). Also -- since I'm getting great coherence out to several [kHz], I can expose and refine the precision the ESD driver pole frequency (nominally at 2 [kHz]; T1000220, specifically, pg. 6 of 'ESD_PA95_circuit_diags_comp_overlays_1_of_6.pdf'; preliminary results are pointing to that it's actually 2.2 [kHz]). 

I'll post full analysis of both measurements compared against all prior measurements in a bit, but this DARM OLG TF I just took lives here:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Measurements/DARMOLGTFs/2015-05-02_H1_DARM_OLGTF_LHOaLOG18181.xml
For this measurement, I 
- decreased the frequency range to *actually* 5 to 5000 [Hz] (because getting down to yesterday's 3 [Hz] took too long). The measurement now takes 25 minutes.
- decreased the drive envelope's amplitude above 1 [kHz] by 2, to make sure (a) I don'tneed to turn of the ETMY L3 stage digital limiters, and (b) I'm sure it's not me ringing up the violin modes
- increased the drive envelope's amplitude below 10 [Hz] by 2, in attempts to get better coherence in the 5 to 15 [Hz] region. It didn't work, will try to drive harder there next time.

Relevant loop gain information also attached.

Not Nutsinee, this is Jim. Didn't see I was still logged in as her.

Evan, Sheila

We have been able to lock the IFO at 10 Watts with a recycling gain of 37.  We also think that we can probably improve our inital alingment scheme by adding a servo from POP A to PR3 durring the INput align step.  We've closed loops around ITMX from the TRX QPDs, these were stable for almost an hour before we dropped the lock for other reasons, and helped keep the X arm build up stable as we increased the power.  

Variation on Inital Alingment 

At the beginning of the evening, our alignment resulted in a rather low recycling gain (15 or something) which resulted in difficulty locking.  This was probably because the ITM camera references would have moved 18033.  We have now gone through an initial alignment with some extra steps which brought us back to a decent recycling gain (35 before any manual adjustment or full lock ASC).  

• First we locked the X arm with both green and IR, and ran two green WFS loops (ETM and TMS), green ITMX camera loop, and the input align WFS loops (REFL WFS to IM4+PR2).  In this configuration Evan moved PR3 to bring the spot position on POP A close to zero, which is the position it was in during a high recycling gain lock last night.  (0.05 Yaw, -0.08 PIT).  This move also increased the COMM beatnote strength, to above 4 dBm.  After this we set the green ITM camera reference again. 
• Then we used this input beam and with the Y arm optics misaligned steered the BS to get red light on the ETMY baffle PDs.  This was a rather different location than what we found in october 14321. We did this by hand since we have never set the gains and phases correctly to use the ditherAlign script for the BS.

• After this we locked the Y arm on green and IR, with green WFS running on the ETM and TMS.  We moved the ITM to maximize the red build up in the arm, and let green WFS take care of the ETM.  After this, we reset the ITMY green camera reference.  Ideally, we would have used red WFS to 
• After that we checked MICH dark which was misaligned by about 0.6 urad, we adjusted the BS to get a nice dark port.  
• Then we did the rest of our initial alignment scheme as usual, PRM ALIGN and SRC align. 

 This resulted in a recycling gain of about 35, so it seems like this was a sucsesful approach at least once.  If there is time for some day time commissioning tomorrow, it would probably be helpful to add to the INPUT align state a loop which actuates on PR3 to center the beam on POP A.  Commissioning the dither Align script for the BS to ETMY baffle PDs might also be helpful, but this is a lower priority because we aren't sure that step is necessary.  

Since we have seen this week that many things (CARM offset reduction, violin and roll mode damping, and ASC error signals, possible radiation pressure instability on the ITMs) change when we go from a bad recycling gain to a good one, it seems like we will want to improve our initial alignment scheme enough to consistently bring us to a high enough recycling gain that we can use consistent settings for lock acquisition.  

Avoiding oscillations durring power up

We ran into the oscillation in ITM pitch which we think is due to mis centering and radiation pressure on the ITMs several times tonight.  It seems like we are more stable when the recycling gain is high, we have also slowed down the final CARM offset reduction and the power increase.  

Closing ITM loops

We were able to close loops around ITMX from the QPD error signals we found last night. Here are settings:

DSOFT P (ITMX P) error signal 1.71 TRX A -1 TRX B FM offset 0.08, FM2,3,4 gain -700,000, top mass offloading on

DSOFT Y (ITMX Y) error signal 1.84 TRX A -1 TRX B FM offset -0.1, FM2,3,4,6 gain 600,000, top mass offloading on

both of these loops respond in a 2-3 seconds.  

DARM OLG

Evan made a measurement of the DARM OLG, this was when we still on ETMX, DC readout with low frequency boost, and a recycling gain of 35.  11 Watts input power. 

Now a large earthquake has tripped most of the seismic platforms.