Yesterday late afternoon GregG switched the HAM1 Actuators from Bleed Mode to Operation Mode; this chamber had been bleeding since 20 May.  The IPS sensors were also zero'd yesterday.

This morning, we unlocked the HEPI, so HAM1 is now floating; the caution signs have been changed.  Please be mindful of all the blue hardware at HAM1.

Also, please avoid using the HEPI Housing area as a tool/parts holder.  There are many very close clearances in the HEPI Mechanical structure and a dropped screw or tool could render them bound up.  This will/could be very difficult to diagnose/find as most of these tight spaces are not visible and barely probeable.

After adding a few channels to the ITMY .ini file, I rebooted the DAQ at 10h03. During the DAQ restart, the daqd process did not come back. It was restarted manually around 10h40 (Dave remotely).

GV1 was closed at ~16:47 utc or 9:47 local time.

Just a heads up, I'll be taking transfer functions remotely on TMSY this morning. HIFO-Y work takes precedent over this, so don't hesitate to call me and tell me to stop!

Attached are plots of dust counts requested from 5 PM June 4 to 5 PM June 5.

Both the dust monitor at location 14 in the LVEA (H2 PSL enclosure) and the dust monitor at location 16 in the LVEA (H1 PSL anteroom) are indicating calibration failures.

(Jax, Alexa, Arnaud, Chris, Sheila, Daniel, Stefan)

We implemented the DC relief to ETMX for the ALS lock

- Implemented a IPC link from H1:ASL-Y_ETM_LONG to H1:SUS-ETMY_L3_ISCINF_L_IN1.
- Added dewhitening filter to H1:ALS-Y_REFL_SMON FM1 (Zeros 10Hz, 10Hz; Poles 100Hz, 100Hz).
- Zerod the electronic offsets in the CM board B and slow path (H1:ALS-Y_REFL_SERVO_COMOFS=0.505V, H1:ALS-Y_REFL_SERVO_SLOWOFS=-1.675V, H1:ALS-Y_REFL_SMON_OFFSET=-1645).
- Added 1/f filer in stages (Z:P: 10:1:0, 1:0.1, :1) and gain of -0.03 in H1:ALS-Y_ETM_LONG filter bank.
- SUSETMY is in "distributed feed-back mode". We feed back only to the top mass.
- H1:SUS-ETMY_L3_ISCINF_L and H1:SUS-ETMY_M0_LOCK_L have a flat gain of 1.

We also killed a 1.3Hz oscillation in the light from the fiber by putting a 20dB,Q=3 resonant gain into the H1:IMC-L path. All this, together with another alignment tweak, made for very stable locks: while I am writing this log the arm stays locked for 20min at a time while the relief integrator is ticking away (Tidal?). I set the limiter H1:ALS-Y_ETM_LONG_LIMIT to 10000 cts to prevent kicking the Quad too hard - this eventually breaks the lock. 

Sheila and I quickly took a peak, but there is no green beam coming out at the corner yet. Not too surprising,.. next we need to align the IR beam to hit the ETM cage.

Things to do with low priority:
- Decouple force to pitch (& yaw) at DC - the alignment degrades slightly for O(1e4) counts of M0 length drive. But its likely good enough for the HIFO work.

[Chris, Kiwamu]

This is a detailed version of the previous IMC WFS entry (see alog 6633).

Actuation issue wasn't really an issue:

 We kept driving the M3 stages (very bottom stage) of MC1 and MC3 to excite the angular motions (alog 6610) but it turned out that this was not the right way. The actuators on M3 are simply not strong enough to excite them with a high signal-to-noise ratio at the wave front sensors. Therefore we need o switch the driving point from the M3 to M1 (very upper stage) to have a big excitation. In fact this is the way the people in Livingston did. After all, exciting M1 gave us a prominent peak in the spectrum of the WFS signals and hence we were able to proceed with the measurement of the sensing matrix.

Balancing of the quadrant segment gain:

During adjusting the demod phase of each segment of the WFSs we noticed that they show different signal gain. In order to correct this gain discrepancy among the segments we changed the digital filter gain to make them identical. We excited the longitudinal motion of the IMC by injecting a 6 Hz sinusoidal signal at INPUT2 of the IMC common mode board servo with an amplitude of 80 mVp-p. This resulted in a peak in the spectrum of each quadrant. Then we adjusted IMC-WFS_A(B)_IX_GAIN and IMC-WFS_A(B)_IX_GAIN where X = 1,2,3,4. Here is the resultant gain coefficients. We are not sure why the gains vary by a factor of 5 at most among the segments. This variation can not be explained by the discrepancy in the transfer gain of the demodulation chain.

H1:IMC-WFS_A_I1_GAIN = 1
H1:IMC-WFS_A_Q1_GAIN = 1
H1:IMC-WFS_A_I2_GAIN = 5.33
H1:IMC-WFS_A_Q2_GAIN = 5.33
H1:IMC-WFS_A_I3_GAIN = 4.43
H1:IMC-WFS_A_Q3_GAIN = 4.43
H1:IMC-WFS_A_I4_GAIN = 1.33
H1:IMC-WFS_A_Q4_GAIN = 1.33
H1:IMC-WFS_B_I1_GAIN = 5.75
H1:IMC-WFS_B_Q1_GAIN = 5.75
H1:IMC-WFS_B_I2_GAIN = 1
H1:IMC-WFS_B_Q2_GAIN = 1
H1:IMC-WFS_B_I3_GAIN = 1.07
H1:IMC-WFS_B_Q3_GAIN = 1.07
H1:IMC-WFS_B_I4_GAIN = 5.47
H1:IMC-WFS_B_Q4_GAIN = 5.47

 

Compensation for the geometrical rotation:

As far as we remember there is a periscope in the IMC-REFL path which rotates the x-y relation of the beam, which rotates it by almost 90 degrees. Due to this effect the actual yaw motion happening in the IMC cavity shows up as almost pitch motion and vice versa at the RFFL port. We corrected this effect by manipulating the input matrix (IMC-WFS_A(B)_I_MTRIX) such that the yaw excitation shows up only in pitch basis after the input matrix. This adjustment was done by exciting the M2 stage of MC2 (which somehow we ended up with for some reason when exciting the angular motions) in pitch and yaw at 3 Hz. As a result the coupling between pitch and yaw were improved and separation ratio became approximately a factor of 50 at least which used to be 1 at worst. Here is the resultant matrix elements.

H1:IMC-WFS_A_I_MTRX_1_1 = 0.478812
H1:IMC-WFS_A_I_MTRX_1_2 = -1.33069
H1:IMC-WFS_A_I_MTRX_1_3 = -0.478812
H1:IMC-WFS_A_I_MTRX_1_4 = 1.33069
H1:IMC-WFS_A_I_MTRX_2_1 = 1.33069
H1:IMC-WFS_A_I_MTRX_2_2 = 0.478812
H1:IMC-WFS_A_I_MTRX_2_3 = -1.33069
H1:IMC-WFS_A_I_MTRX_2_4 = -0.478812
H1:IMC-WFS_B_I_MTRX_1_1 = 0.394297
H1:IMC-WFS_B_I_MTRX_1_2 = -1.35813
H1:IMC-WFS_B_I_MTRX_1_3 = -0.394297
H1:IMC-WFS_B_I_MTRX_1_4 = 1.35813
H1:IMC-WFS_B_I_MTRX_2_1 = 1.35813
H1:IMC-WFS_B_I_MTRX_2_2 = 0.394297
H1:IMC-WFS_B_I_MTRX_2_3 = -1.35813
H1:IMC-WFS_B_I_MTRX_2_4 = -0.394297
 

Measurement of the sensing matrix

The measurement of the sensing matrix went very smooth. We excited the M1 stage of the IMC suspensions. We considered two DOFs in pitch (yaw), namely common (differential) MC1-MC3 and MC2. This is the DOF basis that the Livingston people came up with in the IMC WFS commissioning. The excitation was injected to DOF_1(2)_Y(P)_EXC with an amplitude of 10-12 counts at about 3 Hz. To be sure that we are exciting the pure pitch or yaw we looked at the witness channels for the bottom stage and confirmed that we were exciting the right angular motion. Since we didn't have an auto-script to measure the sensing matrix we used diaggui to measure the transfer coefficient from the excitation to the WFSs. After measuring the 2x2 sensing matrix we inverted it and put it to the control input matrix IMC-INMATRIX_P(Y). In diaggui the frequency resolution was set to 0.01 Hz. Here is the resultant input matrix.

H1:IMC-INMATRIX_P_1_1 = 0.64725
H1:IMC-INMATRIX_P_1_2 = -0.35275
H1:IMC-INMATRIX_P_2_1 = -0.159639
H1:IMC-INMATRIX_P_2_2 = 0.840361

H1:IMC-INMATRIX_Y_1_1 = -0.163134
H1:IMC-INMATRIX_Y_1_2 = -0.836866
H1:IMC-INMATRIX_Y_2_1 = 0.529564
H1:IMC-INMATRIX_Y_2_2 = 0.470436

Closing the loops:

The trial of closing the loops were relatively easier compared with what we did to reach this point. We simply started from a small gain of 1e-4 and we fiddled with the sign. Since this was the first time for us to close the loops we enabled only fundamental control filers, namely FM6 (0.06, 0.1) and FM7(0:1) of IMC-DOF_1(2)_P(Y) and disabled the rest of the fancy filters. We aimed an UGF of  a few 10 mHz or so. The gains were adjusted by looking at the time scale of the control against a disturbance. The gains we ended with were :

H1:IMC-DOF_1_P_GAIN = -1e-05
H1:IMC-DOF_2_P_GAIN = -1e-05
H1:IMC-DOF_1_Y_GAIN = -1e-05
H1:IMC-DOF_2_Y_GAIN = -1e-05
 

What are missing ?:

• Beam pointing servo, which is a part of IMC ASC model and called DOF3, needs to be engaged.
• Spot position measurement to make sure that the beams are not in a crazy position on each IMC mirror
• Further loop optimization
• Automation of the WFS servo enable/diable
• A script to measure the sensing matrix

Valved-in YBM Turbo and sporadically sprayed helium (audible flow) around chambers and misc. ports of Vertex volume currently under vacuum looking for any "easy" big leaks -> detector baseline 4 x 10-9 torr*l/sec -> Note, this exercise does not constitute a "leak test" -> Will do formal leak hunting as opportunities present themselves over the next few days? weeks?  

Modification to external piping recently completed by Apollo -> Entire annulus volume (including gate annulus) had been vented to facilitate this mod -> Gate annulus volume is temporarily combined with rest of annulus volume being pumped by aux. cart -> 1.5" all-metal isolation angle valve to be closed after a few days to re-isolate gate annulus volume (i.e. restore nominal configuration).

The concrete floor at the spool was covered with CPStat after the PEM fence was removed. The CPB jigs were moved to the far side of the beam tube by Apollo and then the tech cleaners removed Sharpie and other egregious "stuff" from them.The ISI storage container top was removed from the VEA and taken to X-Mid. The E-module and spiral staircase were moved down to the end and then the E Module was moved into the VEA. 

A small piece of vinyl was torn up by the big pallet jack used for the ISI. Since the tear is in the Test Stand area, John is contacting the vendor to get a repair taken care of before the ISI is in place.

Morning Alarms:
- CDS all are CPU Max and IOP watchdogs - no action necessary 
- Dust alarms are all due to working people - no action necessary

Morning work:
- forklift work near test stands in LVEA

Currently:
- Filiberto in LVEA fixing cables on the CM servo board.

(Sheila, Alexa)

Reboot EY Ethercat System

Active control was left off to avoid perturbating the investigation of a large unexplained offset whitnessed on MC1.

I turned the active control back on this morning, on both HAM2 and HAM3 ISI to help locking the IMC, and assess performance. Active control is the same as it was for the IMC test:

• Damping loops
• Ryan DeRosa's Blend Filters
• ISOlation loops Level 2 (UGF ~25Hz)

Recent performance spectra can be found here.

On Monday, Andres and I removed the ETMx all-metal lower structure from the staging building test stand and boxed it in prep for a move to Ex for it's monolithic re-build.

[Chris W., Kiwamu I.]

The IMC WFS loop were successfully closed.

We left the the IMC locked with the WFS loops ON to see how they work overnight. Some details will be posted later.

(Jax, Alexa, Stefan, Sheila, Daniel)

Arm locking achieved! 

As of 18:00 local time, we're getting lock to 00 at a level of 10000 cts on H1: ALS-Y_REFL_B_LF_OUT, out of a maximum of about 22000 cts. This is about a 50% drop. 

We've touched up the pitch and yaw to improve locking characteristics. The current positions in pitch/yaw are 

ETM: (-142.7, 197.0)

ITM: (247.5, -271.5)

The current gain on CMB-B input 1 is -18 dB. 

Added H1ECATC1_PLC2.ini, H1ECATY1_PLC1.ini, H1ECATY1_PLC2.ini, H1ECATY1_PLC3.ini to master file, removed H1EDCU_ECATC1.ini.  Also edited H1EDCU_DUST.ini to include H1 diode room dust monitor channels.  Restarted data concentrator, but data concentrator could not parse the H1ECATC1_PLC2.ini file.  Error message "failed to locate first section in ...H1ECATC1_PLC2.ini"  

Edited the new H1ECAT* files, found "units=" missing actual units. Corrected, but the data concentrator still failed with the same error.  Changed slope from 1 to 1.0, removed ^M from the end of the lines, no change, data concentrator still failed.

Finally commented out the H1ECAT*.ini files to restart the data concentrator, as 20 minutes had passed.

Examined the H1ECATC1_PLC2.ini file with "od -c", found 2 unprintable characters at the beginning of the file (octal 377, 376) at the beginning of the file, and each "normal" character has a trailing 000 (byte of value 0) after...

0000000 377 376   [  000   d  000   e  000   f  000   a  000   u  000   l  000

Compare with a working .ini file:

0000000   [   d   e   f   a   u   l   t   ]  

The script that generated the H1ECAT*.ini files needs some repair.