Douglas Daniel, Joe DeRenzis, Thomas Vo

We finished assembling two D1101714, High Quality Wedged 6in Viewport assemblies (double optic). This is the first few articles of this particular assembly and pictures are attached, proof testing and leak testing to be done tomorrow (awaiting test parts from C&B).  One of these assemblies is meant to be installed on HAM1 for the main PSL laser beam, we hope to be ready to connect the light tube this week.

Modifications to the QUAD L1 (UIM) and L2 (PUM) stage CoilOutF filter banks were made via Foton to reflect the latest State Machine Diagrams updated last week.

The changes were saved to the filter text files, and filter coefficients were loaded via the "*_GDS_TP" medm.

The Foton filter text files were committed locally to the "cds_user_apps" Repository checked out under:
'/opt/rtcds/userapps/release/sus/h2/filterfiles/H2SUS*TMY.txt'

Found controller inoperative -> Replaced.  Unit failed in July-will likely need aux. pump cart assistance to get going again.

Note: GV16 alarm resulted as signal is now off-scale "high".  Beam Tube gate valve annulus pressures are monitored by alarm handler

After noticing difficulties with untripping the QUAD watchdogs, I realized that a more sophisticated process is required to restore the QUAD status after a watchdog trip now that there are gigantic P and Y offsets on the TOP stage. Bare with me, it's complicated and convoluted because we didn't imagine this scenario while installing the infrastructure, but it's now on the "to-do" list to get it changed / more straight forward in the future.

For now, the process is as follows:

(1) Turn off the master switch.
(2) Untrip any relevant watchdogs.
(3) Change the gain in the P2P and Y2Y DriveAlign matrix filter banks to 0.00 (you can do this from the screen, or since you (currently) need a terminal open for the next step anyways, you can caput / ezcawrite it too). For example, if you're doing ITMY, that's 

]$ caput H2:SUS-ITMY_M0_DRIVEALIGN_P2P_GAIN 0
]$ caput H2:SUS-ITMY_M0_DRIVEALIGN_Y2Y_GAIN 0

(4) Change the ramp time in the P2P and Y2Y DriveAlign matrix filter banks to 10 sec. (The link to the "full" screen is currently broken, so you'll have to do a "caput" or "ezcawrite" or whichever). For example, if you're doing ITMY, that's 

]$ caput H2:SUS-ITMY_M0_DRIVEALIGN_P2P_TRAMP 10
]$ caput H2:SUS-ITMY_M0_DRIVEALIGN_Y2Y_TRAMP 10

(5) Turn ON the P and Y offsets to the desired value (if they're not on already); turn ON the damping loops (if they're not on already)
(6) Turn ON the MASTER SWITCH
(7) Change the gain of the P2P and Y2Y DriveAlign matrix filter banks back to one. Now that there's a ramp time in the signal chain, it'll slowly ramp up the offsets (and the P and Y damping loops), so the watchdogs won't trip.


--------------------------

The items on the "to do list" in order of difficultly/level of hackiness (from easiest / hackiest to most difficult / do-the-right-thingiest)
(1) Fix the DriveAlign Matrix sub-screen such that
    (a) The "FULL" button works, and it opens the full filter bank (may just require an userapps svn up...)
    (b)  Add the TRAMP epics read/write to every element of the the upper level DriveAlign screen-
(2) Update the auto-damping script to include the above sophistication
(3) Offload what offsets you can to ISI and/or HEPI
(4) Make a model change such that the P and Y alignment offsets can be ramped (e.g. make the DCDRIVECAL gain a full filter bank, or add a ramp to the MASTER SWITCH, or something)
(5) Ask CDS to make the cdsEpicsIn block generate a TRAMP channel as well as a value channel on compile.

Garcia has volunteered to take on items (1) and (2) for now.

The following table reports the frequency of all resonances as measured from TF and PSDs.

HAUX have no explicit fine adjustment to exactly match any of the resonances. However, Yaw is affected by the horizontal distance of the blade tips, can vary a bit during alignment is not usually checked agaist any reference. According to the model, 1 mm of difference in that distance translate in about 0.03 Hz of differece in Yaw resonance. If we have time, we can try playing with the blades to bring the yaw resonances closer...

Friday we re-installed ECD on all suspensions, adjusted the DC pitch of IM4 (that changes when you install ECDs) and run an OSEM calibration (using the same optical lever used for pitch balancing). We plan to do the same with the remaining suspensions Today, and have them ready for more (and possibly final) TF and PSDs tonight.

They were changed from the settings determined on the staging building test stand (first number) to:

H1:SUS-MC1_M1_OSEMINF_T1_OFFSET (-12980) -12987  GAIN (1.156) 1.155

H1:SUS-MC1_M1_OSEMINF_T2_OFFSET (-14639) -14642  GAIN (1.025) 1.024

H1:SUS-MC1_M1_OSEMINF_T3_OFFSET (-13929) -13821  GAIN (1.077) 1.085

H1:SUS-MC1_M1_OSEMINF_LF_OFFSET (-13879) -13761  GAIN (1.081) 1.090

H1:SUS-MC1_M1_OSEMINF_RT_OFFSET (-12265) -12104  GAIN (1.223) 1.240

H1:SUS-MC1_M1_OSEMINF_SD_OFFSET (-12570) -12666  GAIN (1.193) 1.184

I will run TFs next with the Top BOSEMs and then plug in the lower AOSEMs to set their offsets/gains.

Attached are plots of dust counts > .5 microns in particles per cubic foot.

I and Daniel measured the WFS sensing matrix by a very slow (0.1Hz) excitation. This is because POS signal is much smaller (it's naturally smaller for a given mirror angle, and WFS placement is unfortunately such that both WFSA and WFSB are more sensitive to ANG).

Originally before the beam path change, I think Bram and Arberto measured the sensing matrix by giving a large offset to either ANG or POS. I also briefly tried this, but in order to have anything for POS, the offset needed to be so huge that the beam almost comes inside one segment, so I decided that this is not a good method.

Anyway, at 0.1Hz I was able to have a very good coherence for both PIT and YAW, POS and ANG. (Data file is /ligo/home/controls/keita.kawabe/OAT_2012/WFS_sens_20120831.xml)

Sensing matrix for PIT was OK:

WFSA = -0.313*POS -5.056*ANG

WFSB = +0.620*POS - 3.930*ANG

Sensing matrix for YAW was hopeless:

WFSA = +0.139*POS + 2.754*ANG

WFSB=+0.091*POS + 3.751*ANG

Thing is, for YAW, the sign of POS signal for WFSA and WFSB are the same, and in order to subtract large ANG signal we also need to subtract a large portion of POS, making the POS signal even smaller.

We think that the problem is that the beam parameters on the table is different from what was assumed when designing the Gouy telescope. We might try something on Tuesday.

In the mean time, I inverted the sensing matrix and put them in the input matrix:

PIT = [-0.9004, 1.1580; -0.1420, -0.0717]

YAW = [14.5307,  -11.2063; -0.3703, 0.5656]

We turned PIT on and it seems to be doing fine. Didn't bother to do YAW.

(Keita K., Daniel S.)

We changed the reflection path towards the wavefront sensors on the ALS table. Previously, they were picked up through the rejected return beam out of the Faraday isolator. Unfortunately, this Faraday isolator uses a wedged calcite as a polarizer which generates numerous ghost beams which were impossible to separate. Instead, we placed a 10% beamsplitter just before the first PZT mirror to pick-up a fraction of the return beam. We then duplicated the lens in the return path and steered the beam towards the wavefront sensor setup. The beam size on the two wavefront sensors was still too large, so we moved them as close to the last steering mirror as we could. Hopefully, this will yield a more reproducible sensing matrix. 

Using the picomotors interferes with cavity locking and seems to introduce glitches which are clearly visible in the cavity power (see circled regions in the attachment).

[Alex, Cheryl, Deepak, Giacomo]

Yesterday morning we couldn't work to the suspensions due to drilling going on in the LVEA. We used the morning to debug the binary IO: now it is working properly and both the LP status and the Coil Output can be enabled and disabled from the front-end as expected.

In the afternoon we carried a large HxTS barrel from the staging building, changed the disposition of HAUX and cover all of them with the barrel, to ease the effect of air turbulence when taking transfer functions and PSDs. The suspensions were left covered and undamped (and no ECD)for the night. Note that we found the position of many of the OSEMs to be offset by couple hundreds um (or more), while they were initially set to be centered better (sometimes much better) than 100 um. Later investigation (this afternoon) suggested that this was due to a combination of:

- the table not being completely leveled (or flat), so that when you move the suspensions around the position of the optics slightly changes

- the frames being unevenly clamped (we only used 3 clamps yesterday as we didn't know where to find others...)

- the OSEM being not very well tightened, so some of them may have moved during handling of the cables and the suspensions to fit them under the barrel.

We also found that leaving the uninstalled ECD close to the base (instead of putting them further away) did not noticeably affect the position of the optic, as initially suspected (however, installing the ECD does change the pitch, as observed before).

Today we adjusted the pitch of all suspensions to 0+-0.5 mrad (assuming the table levelled to this precision, that we were unable to check) using an optical lever (actually IM4 should be adjusted to +4.1 mrad, but since all the suspensions will need to be balanced again once we put he ECD in, we didn't bother).

We centered the OSEMs (intial centering was well within +- 50 um, but after moving them around it degraded to a little better than +-80), cleaned the setup a bit, clamped the suspensions with 4 clamps each and left them under the barrel.

I took TF of Y, P and L (attached), applying small actuation offsets to make the OSEM work around the central position. The transfer functions show no sign of problems, although the peaks are not exactly all in the same place (as already observed at LLO and expected, as the HAUX design does not include any mechanism to fine tune the resonances' position).

At about 22:05 I left the suspensions quiet and with damping off for the night, so tomorrow we can retrieve data for PSDs.

Thomas V

I measured the output voltage out of the RH drivers for both ITMY and ETMY for different values of input currents (ranging from 0 to 1 amp).  Attached is a spreadsheet of my measurements. Analysis soon to come, along with calibration parameters.

Eric A. - feedthrough protection install on HAM chambers
Thomas V. at End-Y
Keita at End-Y
man-lift work in LVEA.  completed by 10:30am
Bubba running crane in LVEA ~2:00pm
QUAD L2-stage coil output filter modifications in the morning hours before noon.

Updates to the QUAD L2 coiloutf filter modules were installed today on both ITMy and ETMy.  The previous filter files were modified via foton and saved to the usual directory.  The files were committed to the "cds_user_apps" SVN locally under:

'/opt/rtcds/userapps/release/sus/h2/filterfiles/H2SUS*TMY.txt'.

The following is the excerpt from the "H2SUSITMY.txt" file where the L2_COILOUTF_* filters are coded.  The changes were to the FMs 5,6, & 7 for all four coils on ITMY and ETMY.  The filter coefficients for both user models were loaded via the GDS medm for each suspension.  The attached pdf is a transfer function of the filter modules with the original and updated pole/zero pairs.

OLD:  
# DESIGN   ITMY_L2_COILOUTF_LL 5 zpk([13],[129.973],1,"n")
# DESIGN   ITMY_L2_COILOUTF_LL 6 zpk([1],[99.9877],1,"n")
# DESIGN   ITMY_L2_COILOUTF_LL 7 zpk([0.5;249.809],[5;19.9999],1,"n")


NEW:
# DESIGN   ETMY_L2_COILOUTF_LL 5 zpk([12],[110],1,"n")
# DESIGN   ETMY_L2_COILOUTF_LL 6 zpk([1.35],[80.5],1,"n")
# DESIGN   ETMY_L2_COILOUTF_LL 7 zpk([0.5;250],[6;20],1,"n")


-------------------------------------------------------------------------------------------------------
################################################################################
### ITMY_L2_COILOUTF_LL                                                      ###
################################################################################
# DESIGN   ITMY_L2_COILOUTF_LL 0 zpk([129.973],[13],1,"n")
# DESIGN   ITMY_L2_COILOUTF_LL 1 zpk([99.9877],[1],1,"n")
# DESIGN   ITMY_L2_COILOUTF_LL 2 zpk([5;19.9999],[0.5;249.809],1,"n")
# DESIGN   ITMY_L2_COILOUTF_LL 5 zpk([12],[110],1,"n")
# DESIGN   ITMY_L2_COILOUTF_LL 6 zpk([1.35],[80.5],1,"n")
# DESIGN   ITMY_L2_COILOUTF_LL 7 zpk([0.5;250],[6;20],1,"n")
###                                                                          ###
ITMY_L2_COILOUTF_LL 0 21 1      0      0 SimAcqOffL2        0.1022381444281  -0.9950269485578308   0.0000000000000000  -0.9513581602053965   0.0000000000000000
ITMY_L2_COILOUTF_LL 1 21 1      0      0 SimAcqOnL2    0.01018979855460631  -0.9996165783185160   0.0000000000000000  -0.9623720057438665   0.0000000000000000
ITMY_L2_COILOUTF_LL 2 21 1      0      0 SimLPL2         1.198428225279573  -1.9083200482101859   0.9083375891754886  -1.9904437581736589   0.9904583948159983
ITMY_L2_COILOUTF_LL 5 21 1      0      0 AntiAcqOffL2      8.999262730598492  -0.9586809127066087   0.0000000000000000  -0.9954086141798147   0.0000000000000000
ITMY_L2_COILOUTF_LL 6 21 1      0      0 AntiAcqOnL2      58.74299131244113  -0.9695955355155262   0.0000000000000000  -0.9994824154540793   0.0000000000000000
ITMY_L2_COILOUTF_LL 7 21 1      0      0 AntiLPL2        1.000393883340034  -1.9900610320883918   0.9900785927850526  -1.9082531975983987   0.9082707513809170

Throughout the day, the CDS group performed multiple updates (cf Dave & Vern ALOG for details). When the computers were handed back to the users, I encountered some difficulties to restore HEPI BSC6. First, I was surprised by the large offsets on the position sensors (>10K counts ~ 15mils). Then, I realized that the pump was turned off.  But after turning the pump back on, the HEPI did not come back to its nominal position. Some tests are currently being performed to understand what’s wrong with the HEPI at the end station.