Attached is the plot of the high power oscillator PZT voltage.  The last voltage step coincides
with when the input modecleaner and reference cavity lost lock.  The first step in voltage coincides
with my deliberate adjustment of the slow voltage to lock the reference cavity to a different fringe.

    All this was to find a place where the FSS would be relatively okay with the input modecleaner
losing and acquiring lock.  Apart from one or two FSS oscillations when the input modecleaner lost
lock, all the PSL servos appear okay.

Changed the visibility logic for the FRONTEND and HPO maintenance fields.

    The front end visibility calc was formerly "A<34.9".  This was changed to "A<34".
Nominally the front end laser power is 35 W.

    The green HPO maintenance field visiblity calc was formerly "A+B+C+D>396".  This was
changed to "A+B+C+D>360".  This means that instead of requiring maintenance for a 1% drop
in power from each pump diode, maintenance is now flagged when there is 10% drop for each
diode.

    The remaining "warning" is related to the Visual Basic program on the Beckhoff PC
not running.  This is only required when the spectra of the pump diodes needs to be
recorded.

*track AAA: PSL
- fix FSS re-locking problem

*track A: missing RG gain:
- PR2 spot position during alignment
- Add digital camera of BS
- arm optics camera defocus & power monitor
- *** fix the 2x omega diodes for SB recycling gain readout
   - check broadband mod of 2w PDs (POB and AS)
   - new lens in front of POB_B

*track B: noise commissioning?
 - shot noise scaling?
  - check calibration
  - try for 50W stable. Serious trouble with PI?
  - pick operating point, then now-noise commissioning
  - reduce RF45
  - Aux length show exess noise - fix it!

Attached are 7 day pitch, yaw, and sum trends for all active H1 optical levers.

The laser tripped this morning.  The status screen red flagged the following:
 - Xtak chiller flow
 - Interlock OK
 - Frontend Power error (WD)
 - Oscillator Power error (WD)

    Initial thought was that a water leak occurred.  That was not the case.

    Suspect that the power watchdog was tripped because the injection locking was lost.
When the injection locking servo loses lock, the laser power drops and sets off the
watchdog.

    The laser restarted without any problems, other than the alignment into the pre-modecleaner
was off a little.  Upon recovery, the pre-modecleaner had some problems locking.  Went into the
PSL Enclosure to adjust the alignment but by the time we got inside, the pre-modecleaner was locked.
Tweaked the alignment a little.

    Closed the other loops successfully.  After deliberately bringing up and down the input
modecleaner a couple of times, the FSS seemed fine with the occasional PZT oscillation.




  JeffB/Ed/Peter

Sheila, Matt, Kiwamu, Carl, Stefan

Earlier today we tried heating TCS CO2 X-arm with 2Watt (0 Watt into Y), and all we saw was a futher drop in recycling gain.

Tonight (07:29 UTC) we tried the opposite TCS: TCS CO2 Y-arm with 1Watt (0 Watt into X). (Half of what we put into x, because we broke lock on the first try.)

Result: Absolutely nothing - all recycling gains remained the same or further dropped.

Conclusion: TCS CO2 cannot get any recycling gain back.

============================================

Log:

UTC 20160713 23:08:09  all TCS CO2 completely off
 no effect on any sidebands
UTC 20160713 23:16:22  TCS CO2 X to 1 W 
UTC 20160713 23:21:21  TCS CO2 X to 2 W
  recycling gains drop, lock loss
UTC 20160714 07:29:00  TCS CO2 X to 2 W, TCS CO2 Y to 0 W
 recycling gains drop, lock loss

Quick Summary: Commissioning. PR gain and noise hunting. Carl is working on PI. We stayed locked at 40W for a while. Shortly locked at 50W before Bounce mode and PI broke it.

Log (All time in UTC):

0:04 ETMY ISI (PAYLOAD WD) tripped. ETMY SUS is frozen. Dave restarting SUSEY IOP.

4:33 Sheila to ISCT1 aligning POP diode

4:49 Sheila back

~05:05 Ran A2L

- Something interesting happened: As PI started ringing up (ITMY 14979Hz and ITMX 15521 Hz) , moving SRM in the corret direction in order to improve AS90/POP90 helped keep PI under control.

Nutsinee, Sheila

There is something wrong with the REFL and POP cameras, we see no image from them although we shoudl be seeing something on REFL. 

Stefan, Matt, Kiwamu,

The online calibration, aka CAL-CS, is more accurate now; the sign of the simulated ETMY L3 stage (CAL-CSDARM_ANALOG_ETMY) was found to be wrong and we fixed it. Fixing the error resulted in an improved noise level at around 100 Hz in CAL CS. This should not affect the GDS pipe line calibration. The attached shows a comparison of CAL-CS before the fix and an offline calibration using DARM IN1 and the full DARM model (28179). It is clear something wrong was going on in 40 - 200 Hz.

What we changed:

• FM4 (N_per_cnts) in CAL-CS_DARM_ANALOG_ETMY_L3
  • zpk([],[],-0.000000000004239369201660156,"n")  ->  zpk([],[],0.000000000004239369201660156,"n")

This fix gave us an actuator model which is consistent with the measurement (28179) in the sense that the relative phase between the PUM and TST have a relative phase of 180 deg at high frequencies. Also, traditionally, when ETMY had a positive bias, the gain of the L3 stage used to be set to -1 in the O1 era (see for example 25575). Therefore today's fix is consistent with the O1 era too. One thing I still don't understand is the relative calibration difference between GDS and CAL-CS (summary page). The relative magnitude should show of a factor of 2 difference or so around 100 Hz assuming the sign error was only in CAL-CS, but it does not show such a big difference. Not sure why.

Kiwamu, Matt, Stefan

We were still suspicious of the 2-omega RF buildup signals, so we decided to put a line on the PRM length at 303Hz, and demodulate the line. To avoid loop feed-back we turned on the existing "notches" FM8 filter in PRCL1. POP9_I was demodulated at 303Hz in H1:LSC-LOCKIN_1_DEMOD_3_I_OUTPUT.

Assuming good overlap, we would expect the gain to scale as sqrt(carrier recycling gain * 9MHz recycling gain).

Interestingly, the 9MHz sideband drops by about the same amount as the carrier, but with a timne constant of about 10min (vs about 1 min for the carrier).

The attached plot shows the power increase to 40W, without the soft offset adjustment that usually happens right away. All scales (except purple) start at zero at the bottom of the plot.

Conclusions:

- POP18 is not reliable - it suggest a larger gain drop than the optical gain.

- The optical gain (RF9 & carrier) does drop by the same 25% as the carrier, but on a much longer time constant.

Following my talk at the Systems meeting, I've added some pdfs to the DCC entry with 'publicity plots' of the improvements due to the BRS:
G1601529: Tilt- and Sensor-correction filter tuning at LHO.

The figure of merit I apply to these plots is that we want to reduce RMS velocity. I believe this is the correct figure of merit 
from DC up until at least the lowest Quad resonances. This saves us the worry of trying to compare bumps and dips in spectra. In all the 
following plots, the dashed curves represent the high-to-low RMS of the solid curves of the same colour. Most of them start from some 
cut-off frequency, to isolate the low frequency contributions. In general, the output of all inertial sensors can be regarded as noise 
below 0.1Hz, since it's either uncorrelated or it's something that will be common to the ends and the corner.

The only new figure here 'Sensor correction vs not' suggests that the noise injection from sensor correction, about 8e-8m/s from 0.1Hz to DC, 
is lower than the potential benefit of sensor correction, about 9e-8m/s from 0.3Hz to 0.1Hz, even with high winds (25mph) and very low 
microseismic motion. With higher microseism and lower wind, this ratio will only improve. Still, during very quiet times, we may be better 
off disabling low-f sensor correction everywhere.

Nutsinee, Kiwamu,

WP5990

We have (re-) set up the polarization monitors on the HWS table by HAM4. We have confirmed that they are functional. For those who are interested in the polarization data, here are the channels to look at:

• H1:TCS-IFO_POLZ_S_HWS_OUT
• H1:TCS-IFO_POLZ_P_HWS_OUT

In theory, they should be in unit of watts as measured at the HWS table.

[Installation notes]

This time, we have newly installed a short pass optic (DMSP950L from Thorlabs) to pick off the main interferometer beam without getting too much contamination from either the SLED light (790 nm) or the ALS beam (532 nm). The short pass mirror was inserted between the bottom periscope mirror and the first iris (D1400252-v1). Looking at the green light at the table from the end stations, we learned that the beam size is already pretty small and (visually) small enough for the beams to fit into the PDA50Bs without a lens. So we decided to go without lenses as opposed to the previous setup (24046).

The short pass mirror reflects the interferometer beam toward the left on D1400252. We placed a PBS (CM1-PBS25-1064-HP) on the left side of the short pass and placed the PDA50Bs. The power reflectivity of the newly installedshort pass mirror was measured to be 5% +/-3% for 532 nm. The absolute power (assuming the Nova hand held power meter is accurate) of the reflected green light was measured to be 1 uW.

One thing we leaned today was that the green light is not so trustable to get the optimum alignment. We first aligned the optics with the green light and then noticed that the infrared beams were almost falling off of the PDA80Bs. So we then closed the shutters and aligned them with the actual infrared beam.

The manual gain settings are:

• S_POL: 70 dB
• P_POL: 50 dB

The digital gains were also changed accordingly so that the calibration of these channels should be accurate.