• Title: 2/16 OWL Shift: 16:00-00:00UTC (08:00-16:00PDT), all times posted in UTC
  

• State of H1: Locking
  

• Shift Summary: Typical maintenance day

• Incoming Operator: Corey

• Activity Log:

• 15:15 Chris S to EX for beam tube sealing
• 16:03 John to LVEA to Join Bubba
• 16:15 John soft closing GV5&7 to crane genie lift over beam tube
• 16:27 Ryan B restarting alog
• 16:34 Christina/Karen to EY to clean
• 16:51 GVs opening
• 17:01 SNEWS test in
• 17:03 Fil to LVEA to check inventory
• 17:24 Coca-Cola truck on site
• 17:40 Norco truck on site
• 17:40 Hugh, Robert to LVEA
• 17:54 Christina, Karen to LVEA to clean
• 18:12 Fil to EX to install chasis
• 18:46 Hugh to ends for Hepi fluid level check
• 19:08 Fil to EY to install chasis
• 19:12 Kyle to MY
• 19:27 Hugh back
• 19:31 Kyle to EX
• 19:40 Fil back
• 20:23 Kyle back
• 21:56 Hguh moving seismometer into LVEA
• 23:03 Corey resetting PSL WD
• 23:31 Corey into optics lab
• 23:56 Kyle to MY to overfill CP3

At 23:03UTC (3:03pmPST) I reset the PSL Watchdog this afternoon & CLOSED FAMIS Request #3585.

13:55 PST h1tcscs restarted

14:28 PST h1isietmy restarted

14:28 PST DAQ restarted

DAQ restart captures above model changes plus addition of all vacuum controls channels.

The h1boot-backup computer crashed with a kernel panic sometime Friday afternoon (Feb. 12), rebooted using the reset button.

This was moved last week.

Attached are some ASDs and coherence plots.  The reference traces are from a time of 20 to 30 miles winds this morning and the current traces are from an early time in the weekend when things were much quieter.

The Y axis looks good with strong coherence and similar spectra responding to the wind-tilt as expected.  The X axis similarities are okay but not as strong as Y's.  We don't understand the Z axis as the HAM5 unit does not respond to the wind like the ITMY seismometer and the coherence is bad compared to the X and especially the Y.

Aidan is making changes to h1tcscs which requires reading EPICS channels from the Beckhoff system. Here is the current number of H1 models which use CA to read/write data to external systems.

* The mid station IOP models lack a full timing system (no IRIGB signal) and instead get their GPS time from the DAQ via Channel Access.

The list of EZ_CA_[READ/WRITE] channels was obtained by:

cd /opt/rtcds/lho/h1/release/src/epics/fmseq

ls|grep -v "_daq"|xargs grep "EZ_CA_READ"

ls|grep -v "_daq"|xargs grep "EZ_CA_WRITE"

Set the phase using the in-lock stretch from some days ago. We can in principle just change the DC3 and DC4 input matrix and start RF-centering.

I have turned off two heaters in the LVEA. HC4 and HC5 were both set to 4ma control at 18:50 utc.

Bubba and I were able to crane the Genie manlift over the Y beam manifold this morning in order to continue the crane rail work.

GV5 and GV7 were soft closed for the duration from UTC 16:15 to 16:53.

The crane behaved normally.

Are complete. I will post plots when I get a chance.

Laser Status:
SysStat is good
Front End power is 32.63W (should be around 30 W)
Frontend Watch is GREEN
HPO Watch is RED

PMC:
It has been locked 11.0 days, 23.0 hr 23.0 minutes (should be days/weeks)
Reflected power is 3.203Watts and PowerSum = 25.7Watts.

FSS:
It has been locked for 0.0 days 12.0 h and 23.0 min (should be days/weeks)
TPD[V] = 1.415V (min 0.9V)

ISS:
The diffracted power is around 8.004% (should be 5-9%)
Last saturation event was 0.0 days 12.0 hours and 23.0 minutes ago (should be days/weeks)
 

12 Counts on HAM5

Den made some modifications to our DRMI that he thinks might help us lock faster.  

We had all of our integrators zero history immediately, Den added 1 second ramps to the 4:0 in MICH and the 10:0.1 in PRCL with the idea that this can reduce transients when they turn on. 

He also changed our triggering so that SRCL and MICH are triggered together at 20 counts off at 10 coutns (this is about 1/3 of the power build up of POP18).  Before SRCL was triggered at 2 counts.

Den also increased the PRCL gain from 11 to 15, removed the triggering of PRCL FM3 (10:0.1) and engaged it by hand after it locked. (the idea for higher gain being that it is better to supress PRCL well in the SRCL error signal).

He set the SRCL gain to -20 from -45.  

DRMI locked in about two minutes.  Its probably worth testing these settings out more and maybe making an alternate DRMI locking guardian state for testin new settings to see if we can reliably get a faster DRMI time. 

We had an unusual HEPI trip (ETMX) just now.  There doesn't seem to be much happening seismically except for some small wind gusts (not reaching 20mph).  HEPI tripped as well as stage 1 of the ISI, but we are re isolated now and don't seem to have any problems. 

In the first attachment you can see that something happened to the TMS osems on Jan 21st that makes the peak to peak noise increse by more than a factor of 10. This is still the case. 

I then took a look at the osem spectra, (the fast channels which are not DQ) and saw a 16 Hz comb in RT and SD (second screenshot).  Without saving I re ran the measurement including TMSY channels for comparison, and then saw that the comb appeared to have gone away.  Spectra of the 256 Hz DQ channels from the time when I originally saw the 16Hz comb are in the third attachment, there is no comb here. 

The last attached screenshot shows the osem spectra for both TMSs that I am measureing now, there is some oscillation around 1800 Hz.  This is very similar to the behavoir reported in 25062  and 20078

{Rana, Evan}

This evening we looked at the coupling of DCPD bias voltage into DARM.

Each DCPD is biased with +12 V from a linear regulator with a 1 Ω output resistor. We wanted to inject extra bias noise, so we exposed the bias lines with a breakout board at the DCPD chassy in the HAM6 rack (see D1300502). Then we summed in the output of an SR785 across an impedance of 10 kΩ in series with 20 µF (see diagram; green shows the normal DCPD electronics and red shows the addition). The 10 kΩ gives a 1:10⁴ ratio of bias fluctuation to drive voltage, and the capacitor ac-couples the drive so that it does not pull on the bias at dc.

With the SR875 we drove a 1 Vpk line first at 187.3 Hz and then at 62.4 Hz (i.e., the bias fluctuation was 70 µV rms). We looked at the response in DARM (at 2 W dc readout, with DARM still controlled by EX). We had 10 mA dc on each PD, in the 400 Ω transimpedance configuration.

For 187.3 Hz (from 02:03:00 to 05:22:00 Z), the magnitude in DARM was 1.13×10⁻¹⁸ m rms, which implies a coupling of 1.6×10⁻¹⁴ m/V. The noise of the regulator at this frequency was 0.9 µV/Hz^1/2, which implies a DARM noise of 1.4×10⁻²⁰ m/Hz^1/2.

For 62.4 Hz (from 05:33:00 to 05:56:30 Z), the magnitude in DARM was 1.4×10⁻¹⁸ m rms, which implies a coupling of 2.0×10⁻¹⁴ m/V. The noise of the regulator at this frequency was 1.9 µV/Hz^1/2, which implies a DARM noise of 3.7×10⁻²⁰ m/Hz^1/2. Note that there is some room for error here because the DARM control configuration here is not exactly the same as the low-noise configuration. However, the ugf and phase margin should not be too different in the two configurations.

This is very close to the current low-noise DARM noise floor. However, if DARM is limited by voltage noise of the regulators, we should either expect that the DCPD null stream is equal in magnitude to the DCPD sum (it isn't), or the regulator noises are coherent (they aren't).