Transfer functions measured after circuit modifications made to the injection locking field box.

    The gain voltage setting behaviour does not appear to be correct.

TITLE: 11/02 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC

STATE of H1: Lcok Acquisition

INCOMING OPERATOR: Patrick

SHIFT SUMMARY: Bad. All locklosses tonight were caused by PI 18043Hz (Mode27). See alog31111 and comments therein. There were 6 locklosses total. I didn't keep track of all the lockloss times. None of the modes were PLL locked but only one or two casued trouble. Mode 26 also rung up but was able to damp once I get the BP filter to match the peak frequency. Not as straight forward for Mode 27. 

LOG:

08:50 Lockloss

12:06 CO2X 0.2W --> 0.4W

12:09 Intent bit set

12:25 Intent bit dropped. CO2X Guardian finds lock point

12:32 Intent bit dropped. CO2X Guardian finds lock point

12:37 Lockloss

13:05 NLN. CO2X 0.2W --> 0.4W

13:39 Lockloss. Peter wants to make some measurement with the PSL so I kept the IFO down.

14:34 Peter out

Note:

• I also removed I_M saturation warning from the Verbal Alarm script (line 244, I_M=104) so I can listen to something else that's actually important. It got to the point where the alarm would complains every 2 seconds even at NLN. IM3 was saturating but wasn't causing locklosses. I tried clearing history but it didn't help. I guess somebody will have to move it before the next initial alignment.
• First half of the night I tried to make some injection so I can measure frequency noise TF. But since I'm a noob I was able to make DARM spectrum rise only at f>1000Hz and not the entire frequency range. I quit after PI became a consistent issue

Measured transfer functions after yesterday's circuit board modifications.  The MEDM gain slider
was increased from 0 in increments of 3.

Started yesterday evening. Doesn't seems to be equally spaced.

I checked to make sure the line and the BP matches. Changing the phase both on the main PI medm screen and on the damping filter doesn't make a different. The PLL green light is on but Shelia mentioned that PLL is not actually locked and I don't know how to make it locked (some other modes with PLL green light indicator also have red PLL lock status). I also tried to zero the gain as Sheila suggested.

TITLE: 11/02 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC

STATE of H1: Nominal Low Noise/Commission

OUTGOING OPERATOR: Ed

CURRENT ENVIRONMENT: Wind: 16mph Gusts, 13mph 5min avg Primary useism: 0.03 μm/s Secondary useism: 0.29 μm/s

QUICK SUMMARY: Before Stefan left he asked me to make some TF measurement. So I'm going to spend some time doing that before setting the intent bit. Locking went smoothly.

After today's changes to the PMC servo, which included increasing the loop gain, we noticed a familiar bump around 4.2kHz in DARM.  Lowering the PMC gain from 16dB to 0dB made the bump smaller in DARM (see images).  Given the coherence with REFL9, it seems that this is coupling through frequency noise.

We also made a small exploration around the already good PMC input beam alignment.  This didn't have much impact, but it revealed that small changes in the alignment can change the input offset to the PMC servo.  That is, the offset which maximizes the PMC throughput can be changed with small alignment tweaks. Using this effect, we made a 0mV input close to optimal (see second image).

J. Kissel

In order to improve the uncertainty on the parameters the lines are measuring, I've adjusted the line heights of a good fraction of the calibration lines. I'll leave them in like this overnight, and see if we get the expected improvement in the uncertainty (especially as reported by the front-end). 

Line              Freq     Former     New
PCALY             36.7      750       500
                  331.9     2900      5000
                  7.9       20000     5000

ETMY UIM          33.7      60        180
ETMY PUM          34.7      27        81

Note the reduction of the 7.9 and 36.7 Hz modes. We don't always increase line heights ;-).

• the initial alignment mentioned in the mid-shift summary wasn't wihout alignment of IM3 (~200urad in YAW and ~80urad in PIT) and PRM (mostly YAW an a little PIT)
• the first NLN lock was brioken by commissioners moving optics around.
• Email sent to Bubba about orange water in OSB toilet close to labs.

Since the cdsutil avg function kept failing, we replaced it by the average of 20 ezcareads - 0.2sec apart.

This was done in a separate state - PREP_TR_QPD_SUM_OFFSET.

Admittedly not the most aestetic fix, but it seems to work reliably.

Notes:

0) A2L gains of order two are getting suspicious, because it essentially means some coils are shut off.

1) ITMY_Y2L was always large (~-2) , but since 10/29 7UTC it is even bigger.

2) ITMX_Y2L also got big (~2) on 10/29 7UTC

Not sure what to make of this...