The IM alignment shifts have caused locking issues, and so I asked TJ to add an alignment notification for IM1, IM2, and IM3 in DIAG_MAIN.

I've set the notification levels at:

• IM1 pitch and yaw, +/-5urad
• IM2 pitch and yaw, +/-10urad
• IM3 pitch and yaw, +/-10urad

These levels reflect roughly twice the drift in a recent 60 day trend.

Nominal alignment values in the notifications are:

• IM1 p: 187 
• IM1 y: 1118
• IM2 p: 603
• IM2 y: -205
• IM3 p: 1965
• IM3 y: -79

IM3 yaw nominal value may need to be updated in about a month, since it has a sustained downward drift that was present through O1 and continues.

- TJ, Cheryl

Set H0:VAC-MX_CP5_LIC300_LLCV_POS_CTRL_PCT_DEAD_BAND and H0:VAC-MX_CP6_LIC350_LLCV_POS_CTRL_PCT_DEAD_BAND to 0.5.

We seem to have 2-3 times the amount of light into the fiber and available at the end stations. The photodiode measuring the light after the reference cavity and Faraday is saturated and needs a factor of 2 attenuation.

The RF max limits were increased by 2dB on the discriminators. The RF crystal frequencies are about 120MHz lower than before. Around -110MHz and -180MHz in X and Y, respectively. Before they were around 0MHz and -60MHz. Both ALS end station PLLs are locked.

Updated the web page displaying vacuum screen detail to use the correct MEDM screen for MX vacuum detail.

Killed old Met One 227b IOC, started new Met One gt521s IOC for diode room.  Dust monitor still needs to be connected properly and powered up.

This fixed the communication error.

CDS - Continue vac upgrade, also swap in mech room.

Vac - stuck cryo valve at MX

Facilites - Landscapers spraying, timbleweed cleanup. Fans are greased, but swaping out some filters.

PSL - Laser is working but some things aren't working as they should.

Work permits reviewed. Safety meeting most likely.

TITLE: 04/20 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    Wind: 5mph Gusts, 2mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.17 μm/s
QUICK SUMMARY: IMC is locked, ITMX ISI tripped most likely from a handful of large earthquakes in the past 6 hours.

 

The replacement turbine flow sensor seems to be working okay and without any leaks.

Whilst the laser was down, the dark voltage of the pre-modecleaner locking photodiode
and frequency stabilisation reflection photodiode was measured.
  PMC locking photodiode : 23.5 - 23.7 mV
       FSS RF photodiode : -4.6 - -4.7 mV

    Whilst engaging the PMC, the output of the locking photodiode would saturate and latch
at random intervals, causing the PMC to oscillate.  This photodiode was replaced with a
spare.
  old : S1107847
  new : S1107848
The measured maximum power that could fall incident on the locking photodiode was ~63 mW.
These occurred at ~83 degrees and 265 degrees.  The minimum power was ~1 mW, and this
occurred at 167 degrees and 347 degrees.

    After locking the FSS, ~10.1 mW was measured after the Faraday isolator located behind
the reference cavity.  This was increased to ~30 mW by rotating WP4 from 98 degrees to 86
degrees.

    Had problems with the stability of the power stabilisation.  The free-running power
fluctuations transmitted by the PMC were perhaps at most 3%.  Yet when the power stabilisation
servo was engaged, it was working far harder than this figure would suggest.  Not obvious why.
Perhaps it's a scattered light issue?





Jason, Peter

All time in UTC:

23:23 Kyle to EY VEA to write down some serial number.

23:26 Peter and Jason out.

23:46 Jenne and Ross to ISCT6

            Kyle's back

01:49 Noticed H0:FMC-EY_CY_H2O_PUMPSTAT alarm went off. Shortly after got an alarm for high temperature at EY. I called John. Timeseires of this channel around the time it went bad is attached below. The chiller went down at 1:13 UTC and back at 01:52 UTC when John turned the pump back on.

02:10 Ran the random walk script on PSL rotation stage so I can calibrate the calculated power and angle for Stefan.

02:26 Realized that I should have called and check with Jason. Turns out there's a beam dump on IOT2L that can only handle low power according to Cheryl's alog. The full power will go to the table if the IMC is unlocked. I stopped the script right away and asked for the RS to go to minimum power.

03:45 We deciede to call it a night. ALS guardian is complaining about communication issue and beat note strength. ISS is still acting up. IMC is left locked and power into the IMC is 1.9 W.

            In CDS land: H1:DAQ-FW1_UPTIME_SECONDS went white, came back for a while and went white again. I tried call Dave but no one answered.

            H1:VAC_MX_X1_PT_343B_PRESS_TORR alarm went off a couple times.

I also tried to fit the few data points I got from PSL rotation stage random walk script. I've attached a screenshot (second attachment). Parameter A and D seems to be hard coded and couldn't be overwrite on the medm screen (and caput) so nothing's changed.

The MX vacuum controls system was upgraded to Beckhoff this morning. I reconfigured the DAQ by:

• renaming the current minute trend files on h1tw1
• installed the new H0EDCU_VE.ini and H0EDCU_FMCS.ini files
• restarted the DAQ at noon PDT Tuesday

I forgot to check if h1fw1 came back after the restart. It had not done so, but h1fw0 has ran with no restarts. I have just remotely restarted h1fw1.

Still to do: rename all the archived minute trend files on h1tw1

Peter, Keita, Stefan

The ISS is still acting up, so we tried to do some diagnostics.

First we had to adjust H1:PSL-ISS_REFSIGNAL to -1.78V to avoid running out of actuation  range. (The diffracted power RMS still seems bigger than before the upgrade - we now fluctuate between ~8% and ~23%). We also had to increrase the ISS gain to 9dB.

The ISS now initially seemed stable. But we were sitting at 22W into the IMC. Of course, that rotation stage is after the IMC. But nevertheless we noticed that when we reduced the selected power an oscillation appeared in the ISS, that sometimes manages to break the loop.

The attached plot shows the two ISS PDs with 3 traces each:

- Now with an oscillation at 2.5kHz

- Now, with no oscillation

- Before the laser upgrade (and with only the first loop closed)

Additionally, the out-of-loop diode (PDA in plot), sees a significant excess in sensing noise below 100Hz. And there are new peaks at ~950Hz and ~4.2kHz.

We are not really sure what couses all this, but one suspicion is scattered light from the high power beam dumps. Excess scatter noise could explain the difference between in and out-of-loop. Also, the abount of scattered light would likely be reduced when less power is dumped. We do not yet understand the 2.5kHz oscillation, which also seems to be moving around somewhat.