Similar to what I've done for the X1SUSQUAD's model yesterday, H2SUSITMY's model had to have some channels re-arranged given the new M0 / R0 OSEM arrangement shown in T1100327-v3 and D1001725-v7. This update is now complete for H2SUSITMY (only). 

In addition, I've brought the QUAD_MASTER.mdl library part up to the standard we'd finished with the triples at LLO a few weeks ago, in that the M0, L1 and L2 stages now use the SIXOSEM_F_STAGE_MASTER.adl, FOUROSEM_STAGE_MASTER.adl and FOUROSEM_STAGE_MASTER (respectively), and all stages use the sus-subsystem-wide-usable WATCHDOG.c instead of the quad-specific QUAD.c. Because their control schemes are unique to the QUAD, R0 and L3 do not have their own stage master, but are left as part of the overall QUAD_MASTER.mdl library part. Finally, the BIO interaction has been brought up to the "RCG2p3 Strategy" referenced in T1100507.

J. O'Dell, J. Garcia

Continuing with the diagonalization of the FMY M1 OSEMs, mechanical adjustments to the FMY top mass (M1) were made to further decouple the "F1" and "SD" OSEMs from the Yaw DoF.  The same sine wave excitation at 1.4Hz was injected to the "H2:SUS-FMY_M1_TEST_Y_EXC" channel with a 100ct amplitude. The expected contributions to the "Yaw" transfer function should be the "F2" and "F3" OSEMs with desired isolation of the other OSEMs ("F1", "RT","LF", "SD") at ~30dB or less.

Initial measurements indicated the "F1" OSEM to be ~10dB isolated from Yaw, with the other OSEMs at ~30dB isolation. Our reasoning was the "F2" and "F3" OSEMs were not in line with the center-of-mass of M1, causing a slight Pitch that would manifest itself in the "F1" OSEM response.  To lower the COM of M1, a 300g mass was added to the top of M1.  The OSEMs were then realigned to center the flags and the first pdf is the same measurement with this configuration.  The "F1" response is roughly ~20dB lower than "F2" and "F3" and the "SD" response about ~17dB lower.

"fmy_osem_diag_yaw_add_mass_300g_f1align_111005.pdf"

This promising result encouraged us to add more mass to lower the COM further.  A 100g mass was then added to M1. At this time, it was noticed the flag of the M2 LL OSEM was twisted and possibly rubbing against the OSEM photodiode sensor and/or LED source.  The M2 LL OSEM housing was removed, and the subsequent measurement is displayed on the second pdf.  The "F1" isolation is now at ~25dB and the "SD" OSEM now at ~29dB.  

pdf #2 - "fmy_osem_diag_yaw_add_topmass_400g_f1alignm2llosemoff_111005.pdf"

The flag for the M2 LR OSEM was noticed to be twisted as well, and it's OSEM housing was removed.  The current configuration of the FMY is the M2 LL and LR OSEM housings are removed, there is now 400g added mass to the M1, and the M1 LF and RT flags are out of range of their respective OSEM beam paths due to the added mass.

Attached are plots of dust counts > .5 microns.

Second cleaning took place this morning. Garbing and staging cleanrooms were moved into place around the chamber cleanroom. Garb and contamination control supplies were stocked. Particle counts were taken and since they looked good (at both the 72" height and floor level) and purge air was on, the north door was removed. The door blank on the west side of the chamber was also removed.

Comments do not show up as results of search queries for them (I've tested by searching for entry ID #, author name, and keyword search).

With help from Travis, I redid the provisional violin mode measurements on the monolithic stage from 9/24: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=1460 . I used (see attached photo of setup):

* The optical lever laser, with a steering mirror mounted on a Brunson stand to one side of the structure.

* A small audio speaker placed on UHV foil on the cross bar of the structure and pointed toward the fibre.

* A quad photodiode on an second Brunson stand on the other side of the structure, nearest the fibre to be tested.

* A Stanford signal analyzer for excitation and read back.

* A digital oscilloscope in XY for checking the DC spot position as reported by the QPD.

Procedure was:

(i) Adjust the steering mirror location and angle until the shadow of the fibre to be measured is clearly visible in the beam spot on a gloved finger just behind the fibre. 

(ii) Adjust the position of the QPD until the spot is centred per the oscilloscope. 

(iii) Tweak the position of the QPD until the swaying of the mass is clearly visible (sometimes the optimum position is slightly off-centre either horizontally or vertically).

(iv) Set the signal analyser source to 10 V. (The previous measurements used a powered speaker, but the Stanford can drive an unpowered speaker at a fair volume.)

(v) Do a swept-sine measurement from approximately 500 to 530 Hz, with 800 lines of resolution (this takes about a minute).

The peaks were low-Q and had about a 1 Hz bandwidth (see photos of analyser screen). The frequencies were approximately

Left front: 504.5
Left back: 507.5
Right front: 506
Right back: 511

(Here "back" is the AR side, and "left" and "right" are as seen standing at the back.)

Since we've moved forward with the suggested clean up of the TOP stage of a QUAD's cable routing (see T1100327-v3, D080273-v2), this change needed to be accounted for in the test stand's simulink model, given that the order of the analog inputs have changed as a part of the clean up. I've edited, compiled, and installed the simulink model
/opt/rtcds/tst/x1/cds_user_apps/trunk/sus/x1/models/x1susquad.mdl,
to reflect the new input order as defined on D080273-v2:

ADC Channel     Signal
0               M0 F1
1               M0 F2
2               M0 F3
3               M0 SD

4               M0 LF
5               M0 RT
6               R0 LF
7               R0 RT

8               R0 F1
9               R0 F2
10              R0 F3
11              R0 SD

The damping loops for the M1 stage of the FMY on the BSC8-ISI were closed today with the gains tuned. Now that the BIO medms are in place, the 'H2:SUS-FMY_M1_CTRL' value was set to "0xaaa" to enable the test coils. The 'H2:SUS-FMY_M2_CTRL' channel was set to "0xfff" for the M2 stage.

The new damping gains for each DoF are:
H2:SUS-FMY_M1_DAMP_L_GAIN = -1.0
H2:SUS-FMY_M1_DAMP_T_GAIN = -10.0
H2:SUS-FMY_M1_DAMP_V_GAIN = -1.0
H2:SUS-FMY_M1_DAMP_R_GAIN = -0.3
H2:SUS-FMY_M1_DAMP_P_GAIN = -0.05
H2:SUS-FMY_M1_DAMP_Y_GAIN = -0.1

The "burtgooey" gui was used to save a burt snapshot from the request file:
'/opt/rtcds/lho/h2/target/h2susfmy/h2susfmyepics/autoBurt.req'

A burt snapshot of the new configuration is located in:
'/opt/rtcds/lho/h2/userapps/release/sus/h2/burtfiles/fmy_dampfilter_111004.snap'