J. Kissel

Following the same procedure outlined in LHO aLOGs 9453 and 9079, I balanced the coils on SUS ITMY UIM/L1, ITMX PUM/L2, and ITMX UIM/L1. The final balanced gains are

             ITMX UIM     ITMY UIM    ITMY PUM
UL            -0.965      -0.997       +1.028
LL            +1.025      +0.976       -0.911
UR            +0.970      +1.019       -1.091
LR            -1.030      -0.998       +0.968

The precision on the ITMX UIM and ITMY PUM numbers is within the usual +/- 0.5%, but for some reason I was able to get a crazy amount of SNR on ITMY UIM, so the numbers are good to with 0.05%. 

This balancing has reduced the L3 P and Y caused by pringle excitation at 4 [Hz] by
Optic    Stage      DOF       Reduction Factor @ 4.0 [Hz]
ITMX      UIM        P               > 24.2 (peak below noise, totally incoherent)            
                     Y               > 1.39 (already balanced well, totally incoherent after balance)

ITMY      PUM        P               25.6 (peak still 95% coherent*)
                     Y               37.4 (peak still 80% coherent*)

ITMY      UIM        P               > 124.2 (peak still 68% coherent, but buried)
                     Y               19. 0 (peak still 90% coherent)

* For ITMY PUM, I could not reduce the Q phases to as small as I normally get, implying there is some other noise contributing to the imbalance unrelated to the knob I'm tuning. Unclear what that could be, but I guess this is why I couldn't reduce the imbalance low enough that the excitation became buried in the noise as I could with the other stages.

I attach the figures of merit for reducing the imbalance. All SUS have had these values captured in there safe.snaps, which have been committed to the repository... except for ITMY PUM which I found not stored while writing this entry. Will store them ASAP.

Running from OPSWS0. Already had a peek with DTT, and no change after todays fiddling with TMS cables. But, maybe more data will tell us...more. TMS is plugged in and damping now, as well as the quad.

PT124B increased(ing) as a result -> The removal of atmospheric pressure from the O-ring valve's O-ring may have released some dissolved gas -> Flex line connecting RGA to 1.5" O-ring valve doesn't look to be applying any torque to 1.5" valve -> I will be monitoring PT124B from home

Got the final Actuators attached to HAM4 today.  I still need to install the position sensor that was experiencing an interference.  And then access the total position before final closeup.

Tweeked the DSCW Springs to pull the system back up from the additional ACB weight.  We adjusted things attempting to bring the Dial Indicators back to the post final alignment numbers Jim recorded on 5 March.  There is a 10mil (1/4mm) west shift but we are still well within the +-3mm tolerance.  Otherwise we have less than 0.1mm vertical shift and much less than that N/S.

So, ready for HEPI Actuators.

(Jax, Daniel)

Today we measured the RF levels in the ISC field and remote racks at EY and set nominal RF values in the MEDM interface. 

Installed attenuators by cable number:

2dB: 

18-1B2 (RF to phase modulator), 18-1, 13B (RF Preamp to Phase/Freq Discriminator), 14-2B (RF to VCO), 19-1 (71 MHz RF Dist. Amp to Oscillator), 14-1 (24.4 MHz RF Dist. Amp to Oscillator)

3dB: 

16-1 (Freq Divider to Phase/Freq Discriminator)

8dB:

17-1 (VCO to Freq Divider)

15 dB*:

18-5B (RF to VCO)

*Here we would have preferred 12 dB to be consistent with EX as per alog 9466, but didn't have one on hand in the big box o' attenuators.

---

During this process, we discovered the delay line had no output. After cracking it open, we found that one of the ICs (U22) had fried in spectacular fashion - likely a victim of an upside-down power cable at some point. I grabbed a spare (S1103442) from MY, gave it a quick once-over to make sure it works, then installed it at EY.

8:30 am, HFD department, fire hydrant flushing/testing.
9:00 am, Mitchell, Travis and Andres to Y-End, ACB install.
9:00 am, Aaron connect cables for new chassis, CM summing chassis by PSL area.
9:30 am, HFD department, second unit to check on RAFAR boxes ====> done by 11:15 am
10:08 am, Cyrus and Jim to Mid-Y, rack and stack work per WP#4466.===> break for lunch at 12:15 pm.
10:00 am, Thomas and Greg to LVEA North bay area, prep HEPA filter fan unit for craning.
10:55 am, Hugh to LVEA HAM4 area, HEPI installation.
11:21 am, Alexa, X-End, field rack measurements ====> done by 11:53 am.
11:30 am, Thomas and Greg to North bay area, crane HEPA filter on to a table.
11:37 am, Kyle to X-End, check up on access.  To Y-End, check up on purge air====> done by 12:10 pm.
11:40 am, Apollo crew moving ISI to high bay area ====> done by 11:59 am.
1:00 pm, Karen to Y-end, cleaning.
1:09 pm, Keita to Y-End, TMS cabling status.
1:24 pm, Andres to LVEA South and West bay area, hunting for SUS components ====> done by 2:28 pm.
1:30 pm, Alexa and Sheila to X-End, LVEA area.
1:48 pm, Jim and Cyrus, back to Y-Mid to continue with rack and stack ====> done by 3:14 pm.
1:50 pm, Hugh to LVEA HAM4 area, continue with work, then I saw him at Y-End, so who knows.
4:00 pm, Kyle done "making noise" West bay area of LVEA, on elevated BT slab near GV6.
 

THESE CALIBRATION FACTORS HAVE CHANGED

Per Keita's ALOG 10331 and 10454, I have adjusted the optical lever calibration gains for ETMX and ITMX to reflect a more accurate method of calibration that was performed by Keita with the baffle diodes.

ETM

ITM

This morning Mitchell, Travis and Andres installed the ACB.  Mitchell and Travis aligned it with IAS in the afternoon.  Travis left the ETMy SUS unlocked such that final balance checks can be made (and or TFs) this weekend by SEI.  SEI is starting HEPI work there now.

In Keita's ALOG 10454, he pointed out that the  ETMX optical lever yaw sign convention is backwards from the SUS convention.  I fixed this to make them match at 3:35 PM PT and Jeff K is did a save.snap.

Cyrus R., Jim B.

We racked the computer and IO chassis for h1pemmy today at the mid-station.  All of the computing parts are connected, the computer is attached to the network, and the timing chassis is patched through to the master fanout in the MSR. We boot tested the front end as well, without running any models, and Jim verified the BIOS settings.  We are now waiting for an AA chassis with the appropriate PEM modifications to complete the physical install (and in-rack cabling for said chassis has not yet been done).  Models for the FE will also need to be completed/compiled, and the rtsystab/etc. updated.

Aligned the ACB in WBSC10 this afternoon after this morning's installation.  The errors are as follows:

• Lateral: -0.6 mm (South)
  • Tolerance: ±2.0 mm
• Vertical: +0.5 mm (high)
  • Tolerance: ±2.0 mm
  • Note: this is after accounting for the -1.4 mm vertical shift caused by the weight of the alignment target

(Alexa, Sheila)

For the noise budget, we had tried measuring the PDH shot noise by misaligning ITMX and reading out the amplitude spectrum from IMON of the demod. This amplitude spectrum was clearly not pure shot noise at low frequency; there seemed to be some scattering and fringe wrapping (see green line in plot). We went to investigate this by putting a HR 532nm mirror at the bottom of the periscope and repeating the measurement; the noise at low frequency subsequently decreased significantly (see red line in plot -- unfortunately I should have taken more frequency spans). There is stil some acoustic noise at around 100Hz but it's less than in the first measurement (and in the overall PDH noise, the fiber noise is dominant in this region anyway). We removed the HR mirror and tried misaligned ITMX to various different positions and saw that the amplitude spectrum changed around. Clearly, in this measurement we are picking up scattering in the cavity which comes about from misaligning ITMX. We have now convinced oursevles that we do not have any major scattering on the ISCTEX table. 

I have attached the data with the HR mirror in place.

The awgstream software for the control room has been updated to increase the size of the channel list it reads.  This should solve the problem encountered Wednesday in which H1:SUS channels could not be excited using awgstream.

Yesterday night and this morning some diagonalization measurements were taken with pum drive on etmx and itmx. The low coherence for the pitch drive described on the previous alog was due to the optic not centered enough on the oplev, so both ETMX p2p and y2y were remeasured. Those measurements can actually be really fast (15/20min each).
ITMX measurement has some calibration factor of 1.56 for Yaw and 1.83 in Pitch. T1100378 was the reference for calibrating the drive from cts to N.

Attached are the plots comparing the measurement and the model (wirerehang for itmx, fiber for etmx). Note that there is a sign error in ETMX Yaw, so we should double check if that comes from the Oplev sign convention.
 

• The data was processed (removed points with bad coherence) and calibrated in rad/N.m. It lives in :

ITMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Results/quad_{p2p/y2y}.mat

ETMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGL2/Results/quad_{p2p/y2y.mat

• Dtt templates were saved under : 

ITMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Data/2014-03-06_H1SUSITMX_{P2PY/Y2PY}_WhiteNoise.xml

ETMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Data/2014-03-04_H1SUSETMX_{P2PY/Y2PY}_WhiteNoise.xml

• The data was processed with the scripts : 

ITMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Scripts/itmx_L2_diag.m

ETMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGL2/Scripts/etmx_L2_diag.m

The HEPI and ISI are locked at EndY.  SUS is being stopped down and ACB staging/prep is ongoing for installation.

With Jim needing to connect In-Vac cables to feedthrus today, I wanted to update the EY TMS Cable Table (mainly to show recent change of swapping damaged D1000223 cable with D1000225).  All of this follows the BSC10 Cable Routing Configuration (D12000111) & is in the following ICS Assy Load.