WP 6164

When h1brsex reboots, it appears that the C# code starts before the PLC and therefore fails. This does not appear to be case for h1brsey. I have taken out the automatic starting of the C# code and EPICS IOC at h1brsex. I have left the PLC to automatically restart.

I restarted h1brsey twice to check that it had not worked by random coincidence, and it worked both times. I restarted h1brsex more than once and each time it failed.

LHO WP 6151 has been completed. The external links have been upgraded from 1Gb to 10Gb transceivers. Monitoring and tuning of the new connections will be performed in a non-disruptive manner.
Current transceiver light levels:
plugged: SFP/SFP+/SFP28 10G Base-ER (LC)
module temperature: 62.46 C Voltage: 3.25 Volts
RX: 0.13 mW (-8.80 dBm) TX: 1.28 mW (1.09 dBm)

This laser tripped this morning at around 03:00.  Found the NPRO power supply was off.  Suspected problem is either
a mains power glitch or the UPS for the NPRO power supply had a hiccup.

System came up okay except for the ISS, which I am guessing is related to changes made to the sensors as described
by Keita in a previous entry.

Sheila, Jenne, Terra, Matt, Lisa

More complete entries will follow, but the bottom line is that we are still missing the main source of noise below 200 Hz (above 200 Hz jitter/intensity noise should explain most of the noise we see).

We had another long lock today at 50W (broken by  a new PI ) and we tried several things:

- the reduction of the flow rate done in the PSL this morning didn't really last (see  here ), so the PSL table motion is only very very marginally better than it was; 

- Jenne played more with MICH and SRCL FFs, the subtraction is not perfect, but their contribution is negligible at 100 Hz;

- we did AL2, and that reduced a lot the noise below 30 Hz;

- we checked that all the actuators were in their nominal low noise state state; the ITMs ESD had the low pass OFF, so we engaged them (no impact on the noise) - the ESDX bias was at zero as expected, all coils where in nominal low noise states;

- Jenne lowered the 9 MHz modulation depth (see https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=29817), getting rid of the 900 Hz peak;

- Sheila did some exploration of POP offset and IMC WFS offset to minimize jitter (to be continued) - OMC alignment to be checked as well;

- I believe the calibrators have checked the low frequency calibration, and they are confident that it is not off by more than 20%;

- Matt tried to close the ISS with the photodiode in the new location (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=29812), but that didn't work.

 Data around Sep 20, 6 UTC should be good to look at, close to the best low noise state achieved so far. Bruco, actuator noise estimates, checks of couplings with (new wrt O1) TCS-related electronics, and other suggestions are very welcomed. 

We just lost lock about 7.5 hours in to a new PI at 17782.9 Hz.

Never seen this PI before (or any in this range), so I don't yet know what test mass it's from; will take a look in the morning. Ring up shows it has a time constant of about 16.4 sec. 

Matt, Terra

We have 2 modes which are very close in frequency (both around 15540kHz) and we have had some trouble damping them.  To help with this, I modified the PLL filters for these modes to support a lower bandwidth loop, which I hope will be less easily "distracted" by the nearby mode.  The low-pass in FREQ_FILT1 (usually a 1Hz pole) is a modified elliptic which provides significant attentuation at 0.5Hz (ELF0.5), and requires a UGF of about 100mHz.  To support this, the integrator in FREQ_FILT2 is moved down to 30mHz and the gain is reduced to 0.3.  (Note that ELF0.5 has a gain of 0.5 below the cutoff.  This helps to move the UGF down when this filter is on.)

So far this configuration has been working, but should it prove problematic the old filters can be moved back from FM2 to FM3 (which is the FM operated by the guardian).

I used Evan's script to step the 9 MHz modulation depth down by 6 dB.  This was inspired by Koji's alog pointing out that the 9th order 9MHz HOM lines up pretty well with the carrier TEM00 mode (alog 29399), and so is probably what we're seeing on the camera view of OMC Trans.

This noticeably improves the image at OMC Trans - see attached screenshot of camera views.  Both have an exposure of 35000.  Left is nominal, right is -6dB for the 9MHz. 

It also reduced the DARM noise between 900Hz-1kHz.  In the attached spectra, dark purple is the nominal 9 MHz modulation depth of 16.8 dBm, and bright red is the lower modulation depth of 10.8 dBm.  There's perhaps a bit more frequency noise at several kHz, indicating that the CARM gain isn't being increased quite enough (it was increased for this screenshot by 7dB from a slider value of -5 to +2 on the common mode board's IN1 slider).

Tomorrow I'll add this to the ReduceModulationDepth guardian state.

Title:  09/19/2016, Evening Shift 23:00 – 07:00 (16:00 - 00:00) All times in UTC (PT)
State of H1: Working relocking after Lockloss. Environmental conditions are OK. Microseism is low and stable. Seismic activity is a bit rung up in Y. X is also elevated but less than Y. This is consistent with a Gentle to Moderate Breeze (11 – 18 mph).     
Commissioning: Commissioners are working on improving stability at higher powers 
Outgoing Operator:  Ed
 
Activity Log: All Times in UTC (PT)

23:00 (16:00) Start of shift
06:59 (23:59) End of shift


Title: 09/19/2016, Evening Shift 23:00 – 07:00 (16:00 – 00:00) All times in UTC (PT)
Support:  Jenne, Sheila, Lisa, Matt,      
Incoming Operator: N/A

Shift Detail Summary: IFO locked for almost the entire shift. Currently at 51.1W and 35 plus Mpc. Environmental conditions are better than at the start of the shift, with both wind and seismic lower. Commissioners continue making improvements.   

J. Kissel

Now that we're approaching ER10, and the noise is getting back to O1 levels, we need to start tracking the time dependence of the SRCL detuning in the DARM response. As such, with only intuition to guide, I've added a new calibration line at 7.83 Hz, driven by PCALY at a requested amplitude of 20000 [ct] (corresponds to a DAC [ct/rtHz] of 28909, and 8.8e-13 [m/rtHz] of DARM displacement). For a 10 [sec] FFT, with the current sensitivity, this has about an SNR of 10. We can explore driving the line harder, but let's see what we get out of this -- we're already close to the limit of the PCAL AOM, and that's what I used to tune the excitation amplitude. Also note that, although we often use a 10 [sec] FFT as our SNR metric, in practice, we often use 60 or 120 [sec] FFTs (i.e. the time scale on which we expect optical plant parameters to vary), so we'll win there.

I've checked to make sure that this new line
- Does not saturate the PCALY DAC
- Does not saturate the PCALY OFS
- Does not saturate the DARM actuator when trying to control this line (ETMY SUS) 
- Does not generate any substantial harmonics or other non-linear noise in DARM

And I've also accepted the settings for this new line in the safe and OBSERVE snaps for PCALY.

Let's get this line into SLM tool and start analyzing to see if the SRC detuning moves!

P.S. We expect fisher-matrix back-up that this is roughly the "optimal" location for the SRCL line, given that we suspect the optical spring frequency to be around 9.8 [Hz]. Of course, we cannot put the line right on 9.8 [Hz], since that's exactly the frequency of the QUAD's highest vertical mode (a.k.a. "bounce" mode). I've compared 7.93 [Hz] against all of the "do not put a line here" criteria used for the original calibration lines (see LLO aLOG 15870), and this frequency does indeed satisfy those criteria especially since the line is below the astrophysical analysis band.

   Took a 12 hours trend of the PSL Chiller vital signs after this mornings flow adjustment. The various pressures and flows changes in the manifold, chillers, AMP and PWRMETER are not out of the range of expectation. The change in the PWRMETERFLOW is a bit larger than the changes in the other parts. Will monitor this over the next few weeks to make sure all is well. 

   The interesting result is the changes in the four head flows and temperatures. On heads 1 through 3 the flow was reduced by about 0.1 l/m. On HEAD1 the temperature remained constant. On HEAD2 and HEAD3 goes up by 0.1 degree. What is interesting about this is the change in temperature actually smooths out the variation of the high/low temperature range. Need to monitor to see if this is holds up over time.

   HEAD4 has always been the PSL poster child of different, and continues this trend. When the flow was first adjusted it took a relative large drop (0.2 l/m) and over the next three hours the flow recovers to within 0.02 l/m of its original value. The temperature at first goes up and then settles down to its normal value. Whereas on HEAD2 & HEAD3 the temperature goes up and smooths out the high/low fluctuations; on HEAD4 the temperature goes up, then down and then smooths out the high/low fluctuations.  

   It should be noted these changes are actually relatively small. The Crystal Chiller flows around 22 l/m and the Diode Chiller flows around 32 l/m.        

First attachment shows the ISS 1st loop sensors and second loop sensor when 1st loop was engaged but 2nd loop open.

Solid lines are now, and dashed lines are from Friday (the same reference time used in alog 29778).

Even though the ISS state is the same between solid and dashed, 1st loop out of loop sensor (PDA) is much larger than it was on Friday.

It's not like the loop was crazy, as the in-loop sensor (PDB) didn't change, and the second loop sensor didn't change either.

The second attachment is a one-day trend of pointing into the ISS 1st loop QPD (ch1 and 2), various environment signals (ch3 to 11) and PMC trans.

Pointing changed a bit, mostly in DX (this is probably YAW in PSL speak) though PMC transmission increased.

ISS QPD spectrum didn't change much (third attachment).

It's as if the jitter coupling for PDA changed.

   Posted are the ISI HAM & CPS Spectra Checks. Did not notice anything that appeared out of the ordinary.