I'm concerned that trying to solve for higher order optical aberrations coupled with motion of the HWS beam is causing problems in the parameterization of the HWS data. I ammended the HWS code to limit the parameterization of the wavefront gradient measurement to only pitch/yaw, spherical and cylindrical power. Additionally, I lowered the threshold on the intensity of acceptable spots to centroid on the HWS, increasing the number from 24 to 45. The noise in the measured spherical power was significantly reduced as a result (mostly from the simplification of the parameterization).

A plot of the measured spherical power noise floor referenced to the ETM is attached. The scale may be off in absolute magnitude by up to 20% due to the lack of a measurement of the magnification of the optical system as installed; the plot assumes the nominal 20x magnification.

The HAM5 and HAM6 annulus ion pumps demonstrated their ability to maintain the annulus pressure (unassisted by aux. carts) for greater than 2 days with ion current values of 5 LEDs and 6 LEDs respectively.  This was done while the Vertex was under vacuum.  Additionally, no pressure communication was observed on the Vertex MTP CC gauge (@ 3 x 10-7 torr) when the HAM5-HAM6 annulus volume was vented.  

craning in LVEA in the morning
SEI crew near HAM3 for cabling and such
reboots of Simulink user models for FMY, ITMY, & ETMY
SURFs to the Mid-Y and End-Y stations
dome and door install on BSC9

A final tally of 7 ea. total conflat joints could not be made leak-tight in-situ and will need to be reflanged/repaired at some point following the vent.  A quick testing of the welds on the MC output spools will be done just prior to tomorrow's vent.

The dome and two doors were returned to BSC9 this afternoon in preparation for the flooring install that is due to start next Wednesday.

Updates were made to the FMY Simulink user model "h2susfmy" in incorporate the ISI to SUS transformation inputs to the BSFM_MASTER model. There were also three ISC control outputs to BSFM_MASTER that were removed.  The FMY model has been compiled, installed, and begun on 'h2susb78'.

The top level custom model is committed to the CDS SVN locally in:
'/opt/rtcds/lho/h2/userapps/release/sus/h2/models/'

The common library part "BSFM_MASTER" is saved locally in:
'/opt/rtcds/lho/h2/userapps/release/sus/common/models/'

MC2 went into HAM3 on 8/6/12.  View the photo collection in ResourceSpace.

Found that the daqd process had quit on h1nds1.  Last error message in the log file:

Invalid broadcast received; seq=17427618 tp_seq=17427618 gps=1028550222 tp_gps=1028550222 gps_n=62500000 tp_gps_n=125000000

Restarted daqd process.

Note that the daqd process failed in a similar manner on h2nds0 August 6, 2012

J. Kissel, T. Vo

Now that we've [cleaned up/corrected] our analysis of the optical lever calibration (see LHO aLOG 3758), I've installed the new numbers into the appropriate gain field in the optical lever path, H2:SUS-${OPTIC}_L3_OPLEV_${DOF}_GAIN.

The optical levers need centering before new spectra of the calibrated channels can be taken, though.

BUT, the calibration factor has been reduced by 
DOF        Before / After
ITMY P         22.359
ITMY Y         22.382
ETMY P         30.556
ETMY Y         30.544
because we fixed the controller counts to translation stage calibration (from 0.6 [mm/ct] to 6 [um/ct]), used more accurate lever arms (2*L, from 70 [m] and 6 [m] to 56.4 [m] and 6.6 [m]), and threw out some outlier data to get a better linear fit.

Reducing the expected RMS spot motion (on the ETMY, in Pitch, see LHO aLOG 3727 for full explanation of calculation) to 

| dx | = | dTheta_E * L * g / (1 - g^2) + dTheta_I * L / (1 - g^2) |
       = (50e-6/30.556) [rad] * 4e3 [m] * -0.8 [] / (1 - (-0.8 [])^2 ) + (5e-6/22.359) [rad] * 4e3 [m] / (1 - (-0.8 [])^2)
       = 0.012 [m]

or 1.2 [cm], which albeit still large from a performance stand point, is much more believable given what is visible on a camera.

I just turned on the ETMY ring heater to 630mA for each segment to measure the thermal lens with the Hartmann sensor beam.

The first attachment contains plots of all DoFs on MC3 SAGM1 taken last week with DAMPING OFF.  The second attachment plots data from last night with SAGM1 DAMPING ON.   

Today, Filiberto re-routed the external MC2 (and the 1 shared PR2 cable) from the chamberside test area to the chamber feed thru.  From there we spent a little time finding a cable swap and remedying.  ( I *think* the switch is related to the callout of "flooring" positions of the cabble connectors in the cable table brackets.)  We then set the 6 TOP BOSEMs to 50% OLV.  We can now run TFs to kick off SUS Phase 3a testing here.  Not entirely sure who will do this - possibly me when I get in midday.

PR2 glass install chamberside was stalled another day as we discovered contamination on the AR surface in many places (smudges as well as FirstContact overspray?).  We will need to spend some time drag wiping this tomorrow and and then re-attemp the install.

UFl and SEI should feel free to spend some morning time working on table payload if they want/need.  Any MC2 TFs in-progress will be posted or announced.

Can we get new MEDM screens for the TMSY (incl. the little DRIVE CAL screens!). Also, maybe we want to update the safe.snap file ...

Attached are plots of dust counts > .5 microns in particles per cubic foot. Also attached is a plot of the mode of the dust monitor in the clean room over HAM3 (H0:PEM-LVEA_DST15_MODE). This shows when the dust monitor was swapped (see earlier entry).

Attached is a spectrum from last night (7 August 2012), starting a ~23:30h.

There seems to be a narrow spike at 700mHz, while the 2.74 Hz peaks are still there. I guess we nudging downwards ...

After syncing up the userapps/release SVN files on h2build I rebuilt most of the H2 models during Tue maintanance and restarted most models.

A problem with the folding mirror sus models was resolved with a new BSFM_MASTER file. We will install new h2susfmy code tomorrow.

New Dolphin and RFM IPC between ISI and SUS was installed today by Vincent, replacing the EPICS comms link.

New slow channels for PEM (DUST monitor) and HWS were added to the H2 frame.

h2iscey model was changed for ISC -> ALS name change. Please see Bram's alog for details.

This is the transfer function between the phase-frequency discriminator and the FET IQ demodulator while the cavity is locked. The blue trace is "initial" conditions, i.e., with a well-aligned cavity and standard modulation sidebands. The green "sb shift" trace was taken with the RF modulation sideband frequency tuned 200 Hz higher than its initial value. The red "alignment shift" trace was taken with the ITM yaw misaligned. 

The FSR is 37.512 kHz, with a higher-order FSR peak at 75.018 kHz. Given this FSR, the cavity length is 3995.95 m.

The peaks due to the RF modulation sidebands are at 54.432 kHz and 58.098 kHz in the initial trace. These peaks shift 200 Hz in the green trace.

Additional structure is observed at 46.301 kHz, 55.325 kHz, 57.252 kHz, and 66.229 kHz. The peaks at 46.301 kHz and 66.229 kHz increase for the case of yaw misalignment and are thus likely to be (1,0) modes. 

The separations between these peaks are:

75.018 - 66.229 = 8.789 kHz

66.229 - 57.252 = 8.977 kHz

46.301 - 37.512 = 8.784 kHz

55.325 - 46.301 = 9.024 kHz

The mean modal spacing is 8.8935 kHz.

From this modal spacing, the g-factor is 0.540532, corresponding to approximate mirror radius of curvature of 2302.86 m. 

The FWHM of the FSR peak is approximately 94 Hz. Finesse is thus 37512/94 = 399.064. This would occur for a reflectivity of about 99.2%.

There's a follow-up of this in the works for characterizing cavity properties during ring heater use.