1415 - 1425 hrs. local -> To and from Y-end checking RGA bake that was started Thursday morning (discovered that I don't have a WP for this!  Will initiate one today and ask for forgiveness later - its easier than getting permission!)

GV3 AIP died -> will address during the week.

Will make comment to this entry when leaving site.

Ansel and I put the end station CPS timing fan outs on separate +/-18V power this evening in hopes of eliminating the comb of odd harmonics of 1 Hz in DARM. A similar comb had been evident in the magnetometer that I set up at the EY ESD to look for blip glitches, and it went away when we powered the fan out with a separate supply. We think that this is because the magnetometer was detecting ripple in the field radiated from the +/-18V connector on the low V ESD drive and that we eliminated the ripple on ESD power by powering the CPS timing fan out on a separate supply. For this reason we varied from the work permit and didnt put them in a different rack. Ansel will fill in details of the studies he did that made us think that this is the source of the comb (especially if it really does go away in DARM), but we think that the comb isn’t GPS synched because it is driven by a clock on the PSoC board of the CPS timing fan out.  Isolation of BSCs 9 and 10 has been restored to nominal.

Ansel Neunzert, Robert Schofield

[Corey, TJ, Betsy, Koji]

RESOLVED ISSUES:
- The issue of the suspension TF was resolved by adjusting one of the OMC EQ stop holders [LHO ALOG 28900]
- The sign-flip issue of the DCPD signals has been explained by the accoustic noise of the OMC [LHO ALOG 28901]

PROGRESS:
- The lock nuts of the upper mass EQ stops were fastened (by fingers)
- The black glass panels of the OMC shroud were restored. We checked the input/reflection apertures to be well aligned against the beams.
- The OMCT steering mirror was restored to the optical mount.

- The alignment of the WFS path was reviewed. It was found that the path is still well aligned. Just the WFS QPDs were manually aligned by the mounts with picomotors.

- We attached the viewport simulator on the flange to check the alignment of the in-air paths. The AS AIR path was very well centered on the viewport without touching. The OMCR path is about 50% towards East (-Y) from the center of the viewport. We could not find the OMCT spot no matter how we flash the OMC. This could be just the beam was too dim, or was blocked by the shroud. We'll investigate this on Monday again.

TO DO:

- Continue to work on the OMCT path alignment. This requires ~10W IMC input. Try to find a dim flashes. Use a CCD camera on a tripod to find the spot around the viewport cover.
- We want to check the calibration between AS_C QPD SUM, the incident power on OM1, and the incident power on the OMC breadboard.
- Other ISC items function check (picos, beam diverters, fast shutter - see Rich's comment below, etc)
- Ground loop check
- Other SUS/SEI exit check

Purge air has been mysteriously throttled to a "trickle" going into HAM6 (no longer my battle)

Looking at the voltage of the AS port trigger PD as seen by the shutter controller, we have just under 2V at 50W input. The maximum threshold is 2V, so this won't work. The QPD chassis of AS_C has serial number S1301506 indicating an R23 of 26.7K in the sum output. This needs to be reduced to 12.4K, or we have to reduce the modulation depth of the 45MHz before we reach 50W.

The current configuration of the BSC-ISI's does not use any high gain ST2 RX/RY isolation loops because we dont have a blend filter design that rolls off fast enough at low frequency to avoid injecting GS-13 noise back into the X/Y dofs. However, above 1 hz the suspension point motion is dominated by ST2 RX/RY motion. One way we can improve this is by using relatively low gain AC coupled loops on ST2 RX/RY. With RichM's help I've tested this some on a couple ISI's and it seems to work, but there are trade-offs. First attached plot shows the improvement in ETMX longitudinal motion I've managed to get. Green and brown are the ground for both measurements, pink traces are RY loops on, light blues is off. In the 2-10 hz band I can get about a factor of about 2.5 reduction (I've seen up to ~5) , but at about 1 hz the motion is worse by about a factor of 2. Not spectacular, and I'm not sure that the improvement at a few hz is worth the loss at 1 hz. I've looked at the oplev (second plot, pink is on, light blues is off) and the oplev doesn't seem to see a substation difference at 1 hz.

One reason to do this would be to speed recovery after a lock loss. The ISI RX/RY loops get rung up by the impulse from the suspension, and it seems plausible that the ISI would settle down quicker is the RX/RY loops had more gain.

The designs for the ETMs RX/RY loops are included in the attached pdf. The lugfs are around 1 hz, uugfs are around 10-20 hz, phase margins are around 40-50 degrees. Higher gain loops didn't seem to provide much more isolation, but made the motion around 1hz worse.

21:00 - 23:00 UTC

21:05 UTC Joe and Chris done working on wind fence at end X
21:13 UTC Jeff realigning ITMY, misaligning ITMX for crew at HAM6
22:03 UTC Robert and Ansel at end Y. Do not change ISI from damped to isolated.
22:16 UTC Jason done in optics lab

J. Kissel
ECR E1500045
FRS 6014
WP 6051

While attempting to quickly install the ITM updates in between the HAM6 work, I found that ITM models would not compile as is. Errors in the compilation process reminded me that their upgrade would not be as simple as copying and pasting from the ETMs (thanks for all the great error messages, Rolf! They're, sincerely, very useful nowadays). This complexity a result of the differing BIO control of the ESD stage drivers, so the BIO block as a whole cannot be the same. 

Further, I discovered that I forgot to switch the EUL2OSEM matrix on the FOUROSEM_DAMPED_STAGE_MASTER_WITH_DAMP_MODE.mdl library part that controls the L2 stage of both the QUAD_MASTER.mdl (for ETMs) and QUAD_ITM_MASTER.mdl (for ITMs) from a regular matrix to a ramping matrix.

This means that the ITMs are ready for install, and the ETMs need a re-install to gather this bug fix. I'll coordinate with the HAM6 install/repair team and with the CDS crew. 

I've since made the model changes, and all QUADs now successfully compile, but all QUADs will need to have these models installed and rebooted. 

For future reference, changes have been made to 
/opt/rtcds/userapps/release/sus/common/models/
QUAD_MASTER.mdl                  << Modified the BIO block to use the new Individually Controlled 
                                    PUM library block, arranged connections from BIO to L2 
                                    blocks accordingly
QUAD_ITM_MASTER.mdl              << (same as above) Modified the BIO block to use the new 
                                    Individually Controlled PUM library block, arranged 
                                    connections from BIO to L2 blocks accordingly
STATE_BIO_MASTER.mdl             << Created new library block for individual control of PUM driver
FOUROSEM_DAMPED_STAGE_MASTER_WITH_DAMP_MODE.mdl     << Modified COILOUTF bank to accept individual control
                                                       and switched EUL2OSEM matrix from static to ramping

and they've been committed to the userapps svn repo. I attach screenshots of all the relevant parts that have been modified, named after the simulink blocks, respectively.

Removed temporary extension cord for GV15 AIP329 and replaced it with new extension cord, work done under WP 6060, and this closes FRS ticket 5950.

State of H1:  OMC work continues, progress on PDs

Activities:

• 19:08 - Krishna - back from LVEA
• 19:08 - Michael - back from LVEA
• 19:50 - Krishna - back from LVEA
• 19:50 - Michael - back from LVEA
• 19:57 - Kyle - EY - temperature readings
• 20:11 - Koji, Corey, TJ - back to LVEA OMC
• 20:30 - Robert - EY
• 20:38 - Richard - LVEA OMC
• 20:39 - Kyle - back from EY
• 20:55 - Jason - Optics Lab
• 20:58 - JeffK - ITMX and ITMY model restarts

~1330 hrs. local 

Opened exhaust check-valve bypass-valve, opened LLCV bypass-valve 1/2 turn -> LN2 @ exhaust in 45 seconds -> Restored valves to as found configuration. 

Next CP3 overfill to be Monday, August 8th.

Chris B. and Ryan F. reported that during the hardware injections in ER9, the H1:CAL-PINJ_TRANSIENT_OUT channel did not fall below 1e-200 counts until about 1 hour after the last BBH injection. He also said this was not observed in O1. One needs to consider the following two points:

First, one cannot directly compare the TRANSIENT_OUT channel from O1 and ER9 because they had fundamentally different units. In O1, the channel had units of strain, in ER9, it had units of counts. In ER9, the strain time series has passed through the inverse actuation filters.

Second, if one instead looks at the HARDWARE_OUT channel in O1 (after the IAF during O1), any impulse response to the transient signal ending would be completely masked by the continuous wave signal that has been added to the HARDWARE_IN time series. Thus it doesn't make sense to have a 1e-200 threshold on the HARDWARE_OUT channel during O1.

To invstigate the ER9 IAF, I have separately computed the impulse response of the different filters. The biggest impulse response comes from the f^2 filter module because it has high gain at high frequencies (see first attachment). This is to be expected.

I also compare the impulse response of the IAF used in O1 and the IAF used during ER9 (second and third figures, respectively). The O1 actually has a bigger impulse response and longer duration. I would surmise from this that any oscillations are actually worse in O1 than they are now.

Conclusion:
From this investigation, there is nothing to suggest that the ER9 IAF are worse than O1. In fact, the new IAF provide improved signal fidelity and the impulse response suggests that the new IAF is actually better than the O1 version.

J. Warner

Jim has put gathered some data on the wind fence. Check out SEI aLOG 1050.