I have re-attached the LVEA test stand switches* to their respective H1 networks so that the front-ends may be used again.  This involved re-patching in the MSR (links via the H2B), and re-enabling the trunk ports on the MSR FE and DAQ switches (sw-msr-h1fe, sw-msr-h1daq).

*( sw-lvea-h2fe, sw-lvea-h2daq - for historical reasons)

• Jim W. ITMX ISI testing ongoing.
• Hugh, HAM4 Optical lever -> SUS -> Code.  Optical lever is on the works.
  • HAM4, ISI TF investigation.
  • HAM5, ISI TF ongoing.
• Richard, continue with chassis builds, look into seting up camers/illuminators.
• Gerardo, FC applied to test ITM for electrometer measurements today.
• John reported a chiller triped at the corner station, temperature in the VEA went up, but should be under control soon.

JeffK suggess that the changes in this TF may be due to the unlocked HEPI reducing the frequency and Q of these HEPI modes in the ISI.  I can only find HEPI unlocked but with no fluid flowing for HAM3.  In this attached plot, the modes in question (between 10 & 40 hz) have not changed.  Maybe the fluid needs to be flowing, maybe the loops need to be closed as well.  This is why we need to collect lots of data still.

(Alexa, Kimwau)

Yesterday we noticed that we actually had 14W going into the IFO. I adjusted the rotation stage, so that now we have 10W. Kiwamu locked the rotation stage

The ISS gain slider was adjusted from 8 dB to 10 dB.  Any higher results in a number of peaks present in the power noise spectrum.

The file spectrum2.png was taken with the gain slider at 11 dB.  The file spectrum1.png was taken with the gain slider at 10 dB.

Still processing the TFs but likely okay.  Put the HEPI back to cartesian alignment with the Iso offsets.  The hysteresis of HEPI is evident as I had to change the offsets to get back to position.  So if commissioners lose the HAM5 HEPI they may need to again adjust these offsets.  I've got the Rot DoFs to +-500nrads and the Tran DoFs to +-40umeters.

no restarts reported

Follow up analysis of the OMC scan by Dan (ALOG entry13660)

I believe this was done with a single bounce of ITMX.
ITMY had an oplev issue at the time as you can seen in https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=13654

Frequency calibration

Calibratre data points using 0th- to 3rd-order carrier resonances and 0th- and 2nd-order sideband resonances as a frequency reference

Interpolate the frequency calibration by 11th order polynomials (see attachment "OMC_mode_scan_freq_calib.pdf")

Mode identification

Once the frequency is calibrated, the modes can be identified. As the beam is not filtered, it contains all of the sidebands and the sidebands of the sidebands including their higher-order spatial modes. (Attachment "OMC_modes.png" or "OMC_modes.pdf")

In the figure "USB/LSBn" indicates nth-order higher-order mode for upper or lower sidebands for 45MHz modulation.
"usb/lsb" indicates upper or lower sidebands for 9MHz modulation.
"2xUSB0" and "2xUSB0" means 2nd-order modulation sidebands for the 45MHz modulation (i.e. 90MHz sidebands).

Peak fitting

Peak heights of most of the modes are fitted (by hand). (Attachment "OMC_scan_LHO.pdf")

The decomposition of the modes are listed at the end of this entry

Mode matching

From the mode decomposition, the mode matching of the carrier is 0.86 +/- 0.01

Modulation depth

From the ratio of the sideband photocurrent and the carrier photocurrent, the modulation depth for each modulation was estimated

Modulation depth for f1 (9MHz): 0.198+/- 0.006

Modulation depth for f2 (45MHz): 0.305+/-0.003
 

Wiggling some RF cables for the ASAIR_A_RF45 demodulation, I found a bad SMA connector that was for the LO signal at the fied rack. Depending on stress on the connector, it could rotate the phase by about 90 deg. I attempted to fix it, but I could not find the crimping tool kit in the EE lab. We will do it tomorrow once the tools are found. The RF cable is currently disconnected.

I measured the spot position on PRM by using the usual angular dither technique (see for example LLO alog 5010) with PRY locked. It turned out to be pretty good.

• measured vertical off-centering = too low by 2.0 mm
• measured horizontal off-centering = off toward PR3 by 1.0 mm

(some settings):

• ITMX and SRM are intentionally misaligned.
• PRY is locked on the carrier light by REFL_A_RF45_I with a demod phase of 6.9 deg
• No whitening gain, but whitening stage 1 and 2 are engaged to obtain better signal-to-noise ratio.
• Feedback on PRM and PR2 as usual
• servo gain in LSC = -50 which should give a UGF of 30-60 Hz.
• Excitation in SUS-PRM_LOCK_P(Y) with an amplitude of 1000 counts at 10.1 Hz
• I used dtt to take a transfer function of (REFL_A_RF45_I) / (PRM_LOCK_P(Y)) 
• Before the measurement, PRM was tweaked to maximize the intracavity power

(results)

See the plot below.

(some notes)

• At the beginning of the measurement, the beam on REFL_A was at the edge of REFL_A. This resulted in bogus data because it introduced some kind of wave-front-sensing effect as the PRM angle was modulated.
  • This was fixed by moving the tip-tilt mirrors in HAM1, namely RM1 and RM2.
• I used a conversion factor of 42.2 mm for converting the imbalance alpha (see 40m elog 2863 for the definition) into the position of the rotational nodes.
  • According to D1101377-v2,  I used the following numbers to derive the conversion factor:
    • radius of the mirror: R = 75 mm
    • mirror thickness: L = 75 mm
    • magnet separation D = 95.45 mm

Please don't disturb the Matlab session.  -Hugh

WHAM4 only has level 1 robust controllers and we should build Level 2 & 3 controllers as well.  Now that the system is really complete and we only have in-air TFs, it makes sense to run new TFs.  We need to do this just about everywhere.

See the two attached plots to see the new CPS TF completed Wednesday, the response is nicely smooth (in vacuum) compared to the In-Air TFs with HEPI locked on May 23.  Notice the large dip in H3 as well as the shift down and smoothing of peaks between 10 and 50 hz.  Not sure what this means for controller development but it seems important.  I drove with DTT and these seem to still be present.  These features DO NOT appear in the GS13 signals but we do have good coherence here for the GS13.

Running down some funny business.

8:41 Safety audit committee to LVEA for tour

8:51 Jeff B to LVEA to shutdown dust monitors (2,3,4,5,13)

8:53 Filiberto to MidY on AOS parts hunt

9:31 Richard to MidY

9:34 Safety audit committee tour complete

9:36 Jeff B done with dust monitor work

9:41 Greg to EY

9:51 Christina to EX and EY for magnetometer install

10:00 Kyle to soft-close  GV7

10:05 Richard back from MY

11:00 Betsy to west bay on laser barrier hunt

12:00 Greg transitioning EY to laser hazard

12:06 Jim B to LVEA with security review tour

12:33 Jim B out of LVEA

12:44 Greg Mendell to roof with security review committee

12:57 Karen to EY

12:58 Jim to ITMx investigating issues with ISI

13:11 Karen done at EY

13:49 Gerardo to EX, replacing valve on purge air system

13:53 Bubba to LVEA to crane zamboni out

14:55 Jason realigned ITMy OpLev

15:10 Gerardo back from EX

15:10 Gerardo to LVEA west bay CR to FC ITM optic for charging measurements

Soft-closed GV7 (this valve will be opened again in a few weeks and we seek to minimize hard closures) -> Added scroll backing pumps to YBM and XBM turbos (in parallel to QDP80 pumps and independently isolatable) -> Valved-in aux. pump carts to HAM5/6 and HAM4 annulus' -> Valved-in YBM and XBM turbos backed only by scroll pumps -> Shut down QDP80s -> Valved out IP1, IP2 and IP6 

The pressure at the X-end is OK to leave open to BT (saves a cycle of GV20)

Removed and replaced the check valve for compressor No. 4.

Also, about 1 month ago the relief valve for this compressor was replaced.

I've been digging into why my new loops for ITMX won't run and I've found I have a bad CPS (St1-H3). Not really terrible, and probably not responsible for my difficulties. See plot, which was made with the H3 and V3 in-air cables switched, but the original way looked the same, indicating a likely bad board, not the cabling.

   Now that most of the installation work is complete and the over chamber cleanrooms are turned off, I have shutdown and removed the dust monitors from the HAM2, HAM3, HAM4, HAM5, and the X-Arm spool areas. We are currently monitoring the general air in the LVEA via dust monitors in the Beer Garden and the HAM6 end of the tube.  

   While removing the above mentioned dust monitors I found several that had been unplugged from A/C power. The extension cords unplugged from these dust monitors had other things plugged into them. These dust monitors were plugged into A/C power because their batteries are failing (and cannot be replaced). By unplugging these dust monitors they were taken off line and not monitoring the cleanroom environment.

   Please do not unplug dust monitors from A/C power without talking to Jeff B. first.     

When Kiwamu locked PR-X (CH16), POP_A (CH1-7) saw some decent beam, about right in PIT and off in YAW.

POP_B (CH9-15) also saw something, it's not clear if it was the real beam or some ghost, the power is about a factor of 10 smaller than POP_A, and mostly in seg1 and 2.

Anyway, the important thing is that the POP_A already see the beam and POP_B is close.

Don't use pico to center these, though, as POP sled might be a good initial alignment reference.

We should first align the IFO to the POP sled and see if it makes things better. POP sled was aligned perfectly in the last days of HIFO-X/Y. Though a beam splitter was inserted after the vent, the insertion procedure was written such that the sled centering is preserved.