nm

Once IAS finished, Greg & I installed the ISI Blade Spring's TMDs.  SNs 22 23 24 on Springs 1 2 3 respectively.

We had a couple of earthquakes today, a 7.2 near Tecpan de Galeana, Mexico, a 5.6 near Noatak, Alaska, and a 5.5 at Balleny Islands region.

- 9:06 am, Andres to the CS VEA, retrieve items.--> done by 10:17 am.
- 10:01 am, Hugh to CS VEA, HAM5 area for HEPI work.
- 10:01 am, Kyle to Y-End station, open GV18--> done by 10:20 am.
- 10:25 am, Jeff K. from the CR, new code per WP#4573.
- 10:30 am, Kyle to CS VEA, open GV7 and GV5.
- 10:40 am, Corey to CS cleaning area, retrieve garb.
- 10:45 am, DAQ restart for new code.
- 1:00 pm, Karen to Y-End, cleaning.
- 1:05 pm, David to CS VEA, TCS work.
- 1:30 pm, Hugh to CS VEA, continue with HAM5 work.
- 1:55 pm, Matt H. to CS VEA, TCS work.
- 2:04 pm, Cyrus to X-End, comtrol check/work. -->done by 2:33 pm.
- 2:09 pm, Jeff K. more code.
- 2:20 pm, DAQ restart.
 

I ran into a "snag" with the RGA reconfiguration that I had envisioned and won't be able to pump the volume seen by PT246B until next week -> The pumping effect provided by the gauge isn't enough to match the out gassing and the pressure is rising as well as the rate of rise -> If it starts to "run away" I'll have to shut it off but, ideally, it will stay in its safe operating pressure range until I can pump it early next week.

Soft-cycled GV7 so that others could install viewport protector shutters etc -> Dumped unpumped gate annulus volume into pumped annulus volume, opened GV5 -> Dumped GV18's unpumped gate annulus volume into pump cart and decoupled pump cart from annulus plumbing -> Isolated and shut down Turbo and scroll pumps -> opened GV18

The input matrices for WHAM5 are populated and calibration filters are loaded.  With the Actuators attached, the IPS and even better, the Cartesian Position Biases are valid.  The IPSs were zeroed immediately after the IAS look this morning.  So, the 'aligned' position is zero on this chamber.  Likely once I do range of motion etc tests, the system will de stress and certainly local numbers will change.  Usually though the cartesian values tend to cancel, we'll see.

Recommended controls for the different SEI platforms:

BSC-ISI (All) - Guardian ON
Blend: TBetter on all DOF but RZ
Isolation loops: ISO Lv3
Tilt decoupling: gnd-st1 (Matrix, always ON)

HAM-ISI (HAM2, HAM3) - Guardian ON
Blend: 01_28
Isolation loops: ISO Lv3

HEPI (ETMX, ITMX, BS, ITMY, ETMY, HAM2, HAM3, HAM6*) - Command button
Position loops blend filters: 0 on L4C, 1 on IPS
Isolation: Position Loops (Level 1 in command window)

Note: ground-stage1 sensor correction (SENSCOR) is available on BSC-IY and BSC-EX

Recent Updates:

• Smooth ramp installed for the ISI blend switch
• 122880 saturations (60s worth of samples) allowed on HEPI models
• Blend filters cleaned up, and re-installed
• 5Hz UGF generic position loops were installed on HAM4-HEPI*
• ETMY-ISI controls were brought to performance similar to ETMX-ISI
• Every SEI Safe.snap file was updated

Seismic SVN:

• H1 folders (BSC, HAM) cleaned up, and commited

To do list:

• Investigate ~10Hz peak seen on ETMX
• *HAM4-HEPI position loops keep tripping. Gain and phase margin seem ok. Some investigation to be done here.
• Commission HAM5 HEPI
• Clean up H1 HEPI folder and commit.
• Install ISO Lv2 and LV3 on HAM4-ISI
• SENSCOR: BS, and ETMY need gains tweaked
• Install controls (INF, OUTF, Damp, Blend, 3 levels of ISO) on HAM5 and HAM6

I have started to repeat the same noise measurements we made during HIFOY, in particular for the PLL loop (see alogs 9846 and 9251). So far I have made the following PLL measurements:

EY PLL OLTF: see alog 11180. The UGF is at 23kHz with a phase margin of 52 deg.

Beanote measurement: I measured the beatnote out of the direct monitor (-1dBm) of the pre-amplifier. Using the Agiliant spectrum anylzer, the signal strength was -20dBm at 39.62MHz with 100Hz BW. Notably, the medm screen reads back -5dBm which is after the +13dBm. The PLL BBPD DC readback was 2V with 17.8mW. I adjusted the calibration to 0.055A/W (different from at EX).

AG spectrum analyzer noise floor: I measured the noise floor of the spectrum analyzer to be at -122dBm at 100Hz BW.

BBPD dark noise: With the PD completely blocked, the noise was at -116dBm at 100Hz BW.

Shot noise: With only the fiber light blocked at the PD, the noise was at -108dBm at 100Hz BW.

PLL error signal: With the loop locked, I measured the error signal at the IMON of the PFD (i.e. this is a suppressed error signal). I have attached the data; measurements were taken with both the SR785 (EY_PLL_NoiseSpecV_Raw) and with the AG spectrum anaylzer (BBB2.txt) for high frequencies. I have also attached the concatenated data.

Once again, I've had to restore the mapping of keys on the control room keyboards for the controls account so that the caps lock key works.

PLEASE DON'T CHANGE THE KEYBOARD SETTINGS!  IT CHANGES IT FOR EVERYBODY, NOT JUST YOURS!

• X-axis position: -8.5 mm
  • Target: -8.1 mm
  • Error: -0.4 mm
  • Tolerance: ±1.0 mm
• Y-axis position: +6.0 mm
  • Target: +5.5 mm
  • Error: +0.5 mm
  • Tolerance: ±3.0 mm
• Yaw: 518 µrad CW
  • Target: 0 µrad
  • Error: 518 µrad CW
  • Tolerance: ±400 µrad

Since the HEPI actuators are already attached (making adjustment difficult) and the yaw tolerance of the SR3 and SRM optics is large and adjusted on the table (unlike the BSC chambers we do not adjust HEPI to align the optics, we push them on the already aligned ISI) we will ask for a waiver on the ISI yaw.

JimW, HugoP,

With the recent blend design activities, a lot of filter files (.mat) were created, some were duplicated multiple times in the folder tree, while only a few were actually used. Some filters were also installed in the wrong slot, with the wrong name. For example: Start filters were installed in ITMX's TCrappy, TBetter was installed in ETMX's TCrappy. This can be quite mis-leading for the commissioners and we should avoid it.

We figured out which filter files should be used. We took those and gave them clear names in the common BSC part of the seismice SVN as follow, and removed every duplicate we found in the folder tree:

/ligo/svncommon/SeiSVN/seimic/BSC-ISI/Common/Complementary_Filters_BSC_ISI/aLIGO/

• Start:
  Start_Filters_BSC_ISI_2014_02_25.mat  ->  Start_Blend.mat
• T750mHz:
  uses Start_Blend.mat, generic routine automatically adds the trillium to the blend.
• TCrappy:
  some_blend_crappy_fitlers.mat   ->  TCrappy.mat
• TBetter:
  some_modified_blend_crappy_fitlers_040914.mat  ->  TBetter.mat

The Step_6 unit-specific scripts were modified for each BSC-ISI chamber to prevent accidentaly loading the wrong filter into the wrong slot again.

Every BSC-ISI blend filter was reloaded this morning at 9:35AM, from the agreed generic blends mentioned above.

Work will be commited to this SVN today, to facilitate next week's commissioner hand-off.

08:50 Corey, Thomas staging viewport covers by LVEA X arm beam manifold
Kyle soft closed GV7
08:58 Betsy, Travis getting parts from ITM build area
09:11 David H, Matt H. working on TCSX, TCSY
Kyle to open GV5, GV18
09:27 Alexa to end Y to take fiber noise measurements
09:27 Richard done installing lexan viewport cover

Arnaud & Hugh

We quickly looked at this.  We didn't expect an effect but HEPI PS control runs at ~10hz (Epics) and we could check so we did.  The attached looks at the Pier top horizontals over the ground STS2.  All the horizontsl HEPI signals looked the same wrt both horizontals of the STS2s.  First Ref is ISI OFF, HEPI position loop ON, Second Ref is ISI OFF, HEPI Position Loop OFF, current trace is with the fluid flow zeroed.  No affect evident.

I've been looking in to the pier resonance in different chambers over 5 minutes worth of data on 16th/17th of April when the ODC reports good times for a specific chamber. The pier resonance usually appears as an increase in motion (by about an order of magnitude) when you compare the L4Cs at the top of the HEPI piers to the ground STS at ~8 Hz. The first attached image shows this comparison for BS/ITMX/ETMX which all show this pier resonance in the X and Y directions only (this plot is 5 minutes worth of data from the time in the name). If you look at however ETMY (second attached image) things look different. In this image I compared the L4C to the PEM ACC since the GND STS is outputting values close to zero. However the pier resonance seems to be amplified more than other chambers, particularly by this feature at ~11Hz which shows up in X/Y/Z directions. This is causing an extra order of magnitude increase in noise than I would normally expect for the pier amplification at ~11Hz in the X and Y directions. The third plot just shows the BS/ITMY/ETMY aswell. I've looked at several different times of day over both days and the results all look the same. It does not seem to change according to the time of day.

JimW and I worked on getting the performance of BSC-EY comparable to the performance of BSC-EX, before handing off to SUS.

BSC-EY now has the following control tools installed:

• Blend filters: Start, T750mHz, TCrappy, TBetter
• Isolation loops: Lv1, Lv3
• Tilt Decoupling: GND-ST1
• Sensor correction: gains need to be tweaked.

We compared the performance of BSC-EY with the performance of BSC-EX, with both platforms under BSC-EX's most used configuration:

• Blend filters: TBetter
• Isolation loops: Lv3
• Tilt Decoupling: GND-ST1
• Sensor correction:  off
   

Attached Plots show comparable performance of the ISIs, at the projected suspension point, for similar ground motion at both end stations. (plots calibrated in nm and nrad).

One can notice a 10Hz peak, on BSC-EY spectra. We went ahead and took performance spectra at EY with the Isolation off. The peak is also there when the isolation and damping loops are off. Hence, the peak seen at 10Hz is neither caused, nor amplified, by the ISI active controls.

Since SUS provides plenty of isolation at 10Hz, we decided to give them the go ahead to start their testing.

Meanwhile, JimW and I kept investigating. We noticed that HEPI L4Cs were seeing the 10Hz peak too, and that it is mostly seen on the vertical L4Cs (see Page 1 of last attachment). We were able to reduce this peak's amplitude by a factor of ~10 by simply turning HEPI position loops off (see Page 2 of last attachment). It looks like HEPI-EY position loops are somehow amplifying the 10Hz peak, but they are not its source, as the peak still appears clearly with HEPI off.