It appears that the RFM loop on the managed hub (VMIC 5595) is in the opposite way to which we imagined, from the higher numbered port down to the lower numbered port. Because we put the loop together "backwards" it turned out that for the IOP watchdog on the SUS ETMY frontend to communicate with the SEI BSC6 front end less than a foot away phyiscally, it had to run through 8km of fiber because we extended the loop to the LVEA on Tuesday this week. To run through 8km of fiber optics cable takes about 40uS. The IOP runs at 64KHz, with a processing loop taking about 15uS. So not surprisingly the SEI BSC6 IPC receiver was giving 65538 error per second.

The EY ISC was also going through 8km of fiber to communicate with SUS ETMY. This system runs at 16KHz and has 60uS loop time. 40uS could have been just sufficient, and indeed I did see a non-zero communication error rate, at about 1 error per minute.

I reconfigured the RFM loop at EY to the following

[ISC EY] -> [SUS ETMY] -> [SEI BSC6] -> [LVEA SUS ITMY] -> back to ISC EY

Now the EY IOP watchdog error rate is zero. I'll trend the ISC EY -> SUS ETMY to check it is now truely zero, but I watched it for several minutes last night and it was zero.

I am running some TFs on MC2.  This is noted for other tester staff.  Everyone else should continue work as normal in the LVEA.

Vincent left the ISIs on with their new isolation loops tonigiht.  Their performace is noticably better than a few days ago at 1Hz, and the lock is quite stable.  The attached plot shows 3 spectra: green is with the BSC8 ISI tripped, blue with both ISIs running their isolation loops, and red with some more SUS damping (the SUS settings suffered a setback after recent changes to the models).

Dave B., Jeff G.

The Simulink models for H2 SUS ITMY and ETMY were modified today to add the RFM capabilities between the Corner and End-Y stations.  Both models 'h2susitmy.mdl" and "h2susetmy.mdl" been compiled and installed on the frontends 'h2susb478' and 'h2susb6', respectively.  The top level of each custom model needed the inputs re-connected to the common "QUAD_MASTER" library part.  There were six additional inputs added to the "QUAD_MASTER.adl" inputs and three outputs, which were terminated from the top level.  The changes to the top level were also intended to facilitate the use of the newly-installed IPC card on 'h2susb6'. 

Changes saved and committed to the SVN under:
'~/userapps/sus/h2/models/'  as  "h2susitmy.mdl" & "h2susetmy.mdl"

Alberto, Keita and I finalised the WFS beam paths. The beam sizes are ~3-4mm in diameter on each of the WFS, with a picomotor mirror mount as the last optic/mirror before the WFS.

The beams are 'mostly' centered on the WFS. I haven't measured any power levels.

We placed a R=100mm (focal length ~200mm) lens infront of the RF LSC diode. This inturn seems to work properly, and there are no gain fluctuations in the CM PDH transfer function (as was the case with the previous attempt, although it tunred out that we could not work out the focal length of the other lens).

The CM PDH lock is ~12 kHz with -14dB of gain at the input. We may want to shift this gain down the path somehow.

The RF LSC diode gives ~29 mV DC.

It is a long way from being robust, and it is quite slow, but the cavity dither alignment worked this evening.  The commands are:

YAW
./tdsdither 1.9 30 4 0 300 H2:SUS-ITMY_M0_TEST_Y_EXC H2:ISC-ALS_EY_REFL_PWR_MON_OUT H2:SUS-ITMY_M0_OFFSET_Y 10 5
./tdsdither 2.3 50 5 0 300 H2:SUS-ETMY_M0_TEST_Y_EXC H2:ISC-ALS_EY_REFL_PWR_MON_OUT H2:SUS-ETMY_M0_OFFSET_Y 10 5

PIT
./tdsdither 1.9 30 4 90 300 H2:SUS-ITMY_M0_TEST_P_EXC H2:ISC-ALS_EY_REFL_PWR_MON_OUT H2:SUS-ITMY_M0_OFFSET_P 10 5
./tdsdither 2.3 50 5 30 300 H2:SUS-ETMY_M0_TEST_P_EXC H2:ISC-ALS_EY_REFL_PWR_MON_OUT H2:SUS-ETMY_M0_OFFSET_P -10 5
 

The new tdsdither is a perl script replacement for the malfunctioning ezcademod which currently lives in userapps/trunk/isc/common/scripts.  The attached image shows the power increase as the ITM and ETM alignment are dithered.

After a lot of work from Dave and the Jeffs, we got the SUSs running again.  Keita and Bram also finished revamping the ALS WFS telescopes, so there is now beam on ETMY and some power in the cavity.  It should be ready for Hartman work in the morning.

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

Completed the Horizontal Actuator attachment and release of all the Actuators today.  Jason (IAS) checked and we are in spec.  I still want to do to a final Vertical Elevation & Level check of the Table.

• X-axis position/ISI rotation
  • East scale: 0.25 mm South
  • West Scale: 0.1 mm South
  • x-axis position: ~ -0.18 mm (South)
  • ISI rotation: ~75 µrad CW
• Y-axis position
  • Distance measured: 2009 ± 2 mm
  • y-axis position: ~ -0.3 mm (East)

Broadband photodetector S1200235 has been removed from MY, and is now in the LSB for testing of the ALS fiber distribution chassis. 

J. Kissel, F. Matichard, P.Fristchel

After putting together information from all over the everywhere, I've produced (dare I call it) a NoiseBudget for the H2 OAT Y Arm cavity. Attached are the results. 
[[Editorial Note: I've uploaded -v2 of the plots. Now the calibration for the cavity length signal is just 1e-9 [m/nm], as Matt suggests in his comments below. Also removed the free-running laser frequency noise from SARM L budget since it's not applicable when the PLL is on, and corrected the ylabel typo on the Pitch estimate, so it now reads [rad/rtHz] as expected.]]

All data was measured starting at 2012-07-17 04:50UTC (7 averages, BW 0.005, 50% overlap), which we believe is the second stretch of cavity lock shown in LHO aLOG 3463.

Captions (labeled by page number):

(1) The Money Plot, showing the my predicted cavity length against the directly measured cavity length, in [m/rtHz]
(2) A similar model of the cavity pitch, but still a prediction without a measurement that directly confirms it

[[The remaining plots are merely for support of the first two:]]
(3 - 5) For ITMY, individual NoiseBudget breakdown of test mass motion degree of freedom used in the model (L, V, and P)
(6 - 8) For ETMY, individual NoiseBudget breakdown of test mass motion degree of freedom used in the model (L, V, and P)
(9) A comparison between the BSC-ISI's input spectra for Y (projected to L in the model), and RX (projected to P in the model)
(10 - 11) For ITMY and ETMY respectively, the contribution of every degree of freedom input to pitch of the test mass
(12 - 13) Directly measured spectra of BSC8- and BSC6-ISI's ST2 GS-13s,
(14 - 15) Model transer function between all DOFs at the SUS point and the test mass.


Calibration Details:

ISI ST2 GS13s
     - Channels: H2:ISI-$(OPTIC)_ST2_DAMP_$(DOF)_IN1_DQ
     - Input filter calibration: ON (creates an ideal 1 Hz geophone, that asymptotes to 1 [(nm/s) / ct] at high frequency)
     - DTT: (Based on LHO aLOG 3458)
         units: [m]
         gain: 1.59e-10 [m/ct] (1e-9 [m/nm] * 1/(2pi) [rad / (rad/s)])
         poles: 0,0,0
         zeros: 0.7 0.7
         (I gathered/plotted/calibrated the data in DTT for sanity check, then exported the data, uncalibrated, to Matlab)
     - Matlab:
         Used production calibration file:
         $(SeiSVN)/seismic/BSC-ISI/Common/Calibration_BSC_ISI/aLIGO/aLIGO_BSC_ISI_Calibration.mat
         code snippet:
              isiCalibration = load(bscCalibFile);
              gs13Model_nm = abs(squeeze(freqresp(isiCalibration.GS13_Model,2*pi*freq)));
              rawData = load(bscDataFile);
              rawFreq = rawData(:,1);
              for  iChan = 2:size(rawData,2)
                  interpData(iChan,:) = interp1(rawFreq,rawData(:,iChan),freq);
              end 

              for iDOF = 1:6
                  % X Y RZ Z RX RY
                  bscData(1).ST2.CART(iDOF,:) = interpData(iDOF+1,:) ./ abs(gs13Model_nm' * 1e9);
                  bscData(2).ST2.CART(iDOF,:) = interpData(iDOF+7,:) ./ abs(gs13Model_nm' * 1e9);
              end 

Cavity Length Signal 
     - Channel: H2:SUS-ETMY_M0_LOCK_L_IN1_DQ (which is the control signal from the VCO FMON [[I think]], but passed directly to the M0 TOP stage of the QUAD)
     - DTT: (Based on LHO aLOG 3482)
         units: [m]
         gain: 1e-9 [m/nm]
         poles: (none)
         zeros: (none)
     - Matlab: (Based on above)
         code snippet:
              % H2:SUS-ETMY_M0_LOCK_L_IN1_DAQ is already calibrated into [nm], so we just
              % need to multiply by 1e-9 [m/nm]
              cavityData = interpData(14,:) .* 1e-9; % [m] 


Data collection details:

The original data collection .xml can be found here:
$(SusSVN)/sus/trunk/Common/Data/2012-07-17_H2OAT_ASDs.xml

which has been exported to 
$(SusSVN)/sus/trunk/Common/Data/2012-07-17_H2OAT_ASDs.txt


Model script: $(SusSVN)/sus/trunk/QUAD/Common/MatlabTools/plotsinglearmmotion.m

The safe-state burt backup file for H2SUSETMY was updated yesterday after some newly-installed Simulink parts were added to the "h2susitmy" user model.  The damping filters were turned off and DC alignment offsets zeroed for the snapshot.  The snapshot file is under SVN control locally in:
'/opt/rtcds/userapps/release/sus/h2/burtfiles/etmy/h2susetmy_safe.snap'.

The DC alignment offsets on the ETMY M0 stage used to align the beam were initially:
H2:SUS-ETMY_M0_PIT_OFFSET = -2820
H2:SUS-ETMY_M0_YAW_OFFSET = 1215

These values were set to zero for the safe snapshot file.  This file is used by the start-up process when rebooting the user model "h2susetmy".  The intention is to have the system in a state that is not actuating on the suspension when rebooted.

Nothing seems to work (MEDM screen all white), and from Dave's alog entry it sounds as if RFM work was not the direct cause of this.

Why no alog?

I measured the TMS ISC table angular and lateral stability when the end station VEA was quiet last night.

I found the table displacement to be around 5-10 um rms laterally and 1-3 urad rms in angle over 100s. The motion thus appears to be within the requirements: 100 um and 1 urad, respectively.