at 14:11 PST h1dc0 froze up with a kernel panic. We reset the computer by pressing the front panel RESET button, but it did not come back cleanly.

When h1dc0's daqd process first was restarted, it ran for only a short period and then died. It was logging GPS timing jumps of one to many seconds.

Monit restarted it and it is now running correctly. The other DAQ systems restarted at this time correctly, except h1broadcast0 took a long time to get going.

Frame gap due to this problem is

1139782208 to 1139782912

Feb 17 2016 22:09:51 UTC to Feb 17 2016 22:21:35 UTC

The TCS simulation model to estimate the lenses and ROC of the optics is now running. The following lists gives the nominal values and the transfer functions used for all the filters:

ITMX/ITMY:

• TR-X calibration: H1:TCS-ITMX_SIM_ARM_POWER_WATTS_PER_INPUT_UNIT = 1
• TR-Y calibration: H1:TCS-ITMY_SIM_ARM_POWER_WATTS_PER_INPUT_UNIT = 1
• Absorption: H1:TCS-ITMX_SIM_SURF_ABSORPTION = 250E-9
• Absorption: H1:TCS-ITMY_SIM_SURF_ABSORPTION = 250E-9
• Surface defocus:
  • ITMX ROC nominal: H1:TCS-ITMX_SIM_SURF_ROC_NOM = 1939.3m (see galaxy website ITM serial number 03)
  • ITMY ROC nominal: H1:TCS-ITMY_SIM_SURF_ROC_NOM = 1939.2m (see galaxy website ITM serial number 11)
  • ITMX/ITMY self absorption transfer function (derived from a COMSOL model and fitted to double-exponential in MATLAB):
    • poles = [1.195E-4, 9.1E-4],
    • zeros = [2.115E-4],
    • steady state gain, H1:TCS-ITMX_SIM_SURF_DEFOCUS_SELF_GAIN = -3.652E-5 diopters per Watt (-ve sign comes from the fact that self-absorption makes the surface flatter, or ROC longer)
  • ITMX/ITMY ring heater - electrical power to radiated power transfer function (15-minute time constant)
    • poles = [1.768E-4]
  • ITMX/ITMY ring heater transfer function (fitted from COMSOL - surfTFRH):
    • poles = [2.0693E-5, 2.4992E-5]
    • zeros = [8.8689E-6]
    • steady-state gain: H1:TCS-ITMX_SIM_SURF_DEFOCUS_RH_GAIN = +1.06626E-6 diopters per Watt (+ve sign comes from the fact that RH makes optic surface more curved), derived from Figure 4 in T1200465
• Substrate defocus:
  • ITMX/ITMY ring heater - electrical power to radiated power transfer function (15-minute time constant)
    • poles = [1.768E-4]
  • ITMX/ITMY ring heater thermal lens (single-pass): fitted to LLO measurements
    • poles: [3.908E-5, 6.385E-6]
    • zeros: [2.6983E-6]
    • steady-state gain: H1:TCS-ITMX_SIM_SUB_DEFOCUS_RH_GAIN = -9.0E-6 diopters per Watt (RH cause a -ve lens in the substrate)
  • ITMX/ITMY CO2 laser (single-pass): fitted to data in aLOG 14722
    • poles: [6.413E-4, 6.956E-5]
    • zeros: [1.24E-3]
    • steady-state gain: H1:TCS-ITMX_SIM_SUB_DEFOCUS_CO2_GAIN = +62.3E-6 diopters per Watt (see aLOG 14722)
  • ITMX/ITMY self-heating thermal lens: from COMSOL
    • poles: [5.0827E-4, 8.2714E-5]
    • zeros: [1.3062E-4]
    • steady-state gain: H1:TCS-ITMX_SIM_SUB_DEFOCUS_SELF_GAIN = +4.8709E-4 diopters per Watt (self heating lens is +ve in the substrate)

ETMX/ETMY:

• TR-X calibration: H1:TCS-ETMX_SIM_ARM_POWER_WATTS_PER_INPUT_UNIT = 1
• TR-Y calibration: H1:TCS-ETMY_SIM_ARM_POWER_WATTS_PER_INPUT_UNIT = 1
• Absorption: H1:TCS-ETMX_SIM_SURF_ABSORPTION = 250E-9
• Absorption: H1:TCS-ETMY_SIM_SURF_ABSORPTION = 250E-9
• Surface defocus:
  • ETMX ROC nominal: H1:TCS-ETMX_SIM_SURF_ROC_NOM = 2241.54m (see galaxy website ETM serial number 08)
  • ETMY ROC nominal: H1:TCS-ETMY_SIM_SURF_ROC_NOM = 2238.9m (see galaxy website ETM serial number 12)
  • ETMX/ETMY self absorption transfer function (derived from a COMSOL model and fitted to double-exponential in MATLAB):
    • poles = [1.033E-4, 7.5E-4],
    • zeros = [1.8511E-4],
    • steady state gain, H1:TCS-ETMX_SIM_SURF_DEFOCUS_SELF_GAIN = -2.931E-5 diopters per Watt (-ve sign comes from the fact that self-absorption makes the surface flatter, or ROC longer)
  • ETMX/ETMY ring heater - electrical power to radiated power transfer function (15-minute time constant)
    • poles = [1.768E-4]
  • ETMX/ETMY ring heater transfer function (fitted from COMSOL - surfTFRH):
    • poles = [2.0693E-5, 2.4992E-5]
    • zeros = [8.8689E-6]
  • • steady-state gain: H1:TCS-ETMX_SIM_SURF_DEFOCUS_RH_GAIN = +1.06626E-6 diopters per Watt (+ve sign comes from the fact that RH makes optic surface more curved), derived from Figure 4 in T1200465
• Substrate defocus:
  • ETMX/ETMY ring heater - electrical power to radiated power transfer function (15-minute time constant)
    • poles = [1.768E-4]
  • ETMX/ETMY ring heater thermal lens (single-pass): fitted to LLO measurements
    • poles: [3.908E-5, 6.385E-6]
    • zeros: [2.6983E-6]
    • steady-state gain: H1:TCS-ETMX_SIM_SUB_DEFOCUS_RH_GAIN = -9.0E-6 diopters per Watt (RH cause a -ve lens in the substrate)
  • ETMX/ETMY self-heating thermal lens: from COMSOL
    • poles: [4.1996E-4, 7.0555E-5]
    • zeros: [1.1155E-4]
    • steady-state gain: H1:TCS-ETMX_SIM_SUB_DEFOCUS_SELF_GAIN = +3.8577E-4 diopters per Watt (self heating lens is +ve in the substrate)

This morning while TJ was trying to relock, ETMX HEPI tripped again. Kiwamu, Sheila and I all poked around at this a bit and can't find an obvious culprit yet. It's definitely something to do with the X HEPI position (tidal or something else). First attached plot is the ETMX actuators time series at the trip. The little shark tooth just before the trip seems to be caused by something in tidal (a reaction to HEPI walking off, maybe? Or something causing the IMC to do something weird?). When I looked a the cartesian signals, the movement seems to be all in X. The second plot is the time series over the same 32 second window of a few other signals, but none of them are particularly enlightening. The dark blue trace on the middle left is the HEPI X location, which goes on some 30 micron excursion, which ultimately causes the lock loss. But the motion seems to be chickens/eggs. Did tidal get some other input that drove HEPI or did HEPI go crazy and drive off tidal? I don't know.

model restarts logged for Tue 16/Feb/2016
2016_02_16 13:58 h1tcscs
2016_02_16 14:27 h1isietmy
2016_02_16 14:29 h1dc0
2016_02_16 14:31 h1broadcast0
2016_02_16 14:31 h1nds0
2016_02_16 14:31 h1nds1
2016_02_16 14:31 h1tw1

Maintenance day. TCS and ISI-ETMY model changes. H0EDCU_VE.ini change. Related DAQ restart.

Wed 10/Feb/2016 - Mon 15/Feb/2016 No restarts reported.

TCS model change. WP5732

Dave, Aidan:

Aidan made model changes to h1tcscs.mdl 

Buried EY Seismometer added to h1isietmy model. WP5733

Jeff, Robert, Dave:

h1isietmy was modifed to read the external seismometer, these channels were added to the science frame.

Adding all Vacuum Controls channels to the DAQ. WP5731

Dave:

All the vacuum controls channels were added to the DAQ. Increased the number of channels from 280 to 1777

DAQ restart

Jim, Dave:

DAQ was restarted to support all the above changes. After several hours h1fw1 became unsynchronized to h1fw0 (we had not seen this before). Restarting h1fw1 fixed this.

GLIBC patching

Dave:

Patched and restarted critical servers and about half of the control room workstations.

I filled the PSL diode chiller with 350ml of water.  Attached is a 30 day plot showing where the diode chilller was filled on Feb 4th, and then the alarm level increasing starting around Feb 13th.

I have increased the LLCV valve setting to 18% (from 15%) to try and compensate for changing conditions.

Factors that are changing are:

The supply pressure is falling as the liquid level in the storage dewar falls.

Heat leak to the liquid transfer line is increasing with outdoor temperature. This results in more vapor in the line and less liquid to the pump.

Radiation from the beam tube as the beam tube warms.

The attached plot shows 100 days of the control valve setting. The flat line at 15% is due to the failure of the differential pressure sensing- we have had to resort to manual setting of this valve.

Here is a 45-day trend of HEPI Pump Pressures & Drives (thus closing out FAMIS # 4517).

A few note:

• EX Pressure & Voltage drive, made slight shift down on Jan 5th (and the noise levels became quieter)
• EY Pressure & Voltage drive had shifts on 1/21 & 1/27;  in between these dates the noise levels were noisier than before and after.

Attached is a time series of TMSX roll osems over the last year, which has been slowly drifting in the same direction the whole time.  There was a went in June, wich is the larger jump, you can see when the sat amp started to oscillate a few weeks ago, and me moving roll over the weekend. This drift is mostly seen in F1, I don't know if it is real or not.  

Rana has told us that at LLO the TMS QPD positions are sensitive to roll.  Before closing the soft loops we moved roll by 250 urad (accroding to the osems) and saw that this had no impact on the error signals of the soft loops.  

Here are optical lever 7-day trends; closing out FAMIS # 4392.

Masayuki

The ISS 2nd loop medm screen has been Improved. The digital path has been shown.

I have noticed that h1fw1 is lagging quite a ways behind h1fw0 (they are normally synced to the second for the fast data CRC and within a few seconds of writing frame files). h1fw1 was lagging 1 to 10 seconds on CRC and up to 20 seconds for frame writing.

17:47PST, restart h1fw1 daqd process. h1fw1 is now back in sync. The lack of CRC sync lead me to think this is a daqd problem and not a Solaris QFS slow raid.

Jeff, Darkhand, Kiwamu,

We have been meaning to do this, but kept missing a chance to do. Today we have fliiped the sign of the ESD bias voltage both on ETMX and ETMY.

This alog only describes what we did on the digital front end models. We will perform a set of confirmation measurement and verify the H1 DARM model later.

See alog 22135 for a concise summary of the bias flip.

[Bias flip on ETMY ]

• We flipped the bias request voltage from +9.5 => -9.5 in SUS-ETMY_L3_LOCK_INBIAS
• No other change required in SUS-ETMY because there is a if statement in ISC_LOCK which automatically checks the change in the bias sign and compensate for it by changing the sign of L3_DRIVEALIGN_L2L_GAIN.
• In CAL-CS, we have changed DARM_FE_ETMY_L3_DRIVEALIGN_L2L_GAIN from +30 to -30.
• Similarly, we have changed DARM_ANALOG_ETMY_L3_GAIN from -1 to + 1.

[Bias flip on ETMX]

• We flipped the bias request voltage from -9.5 to +9.5.
• We flipped DRIVEALIGN ellements as follows.
  • SUS-ETMX_L3_DRIVEALIGN_L2L_GAIN, from +1 to -1
  • SUS-ETMX_L3_DRIVEALIGN_L2P_GAIN from +0.021 to -0.021
  • SUS-ETMX_L3_DRIVEALIGN_L2Y_GAIN from 0.007 to - 0.007
• We changed the force coefficient of the linearization from -124518.4 to + 124518.4 in SUS-ETMX_L3_ESDOUTF_LIN_FORCE_COEFF
• All the the above changes are now written in ISC_LOCK with a if statement, so that it automatically checks the bias sign and apply a proper set of parameters.
• We have not updated CAL-CS for ETMX because it is currently not in use.

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.

{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).