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

Bram, Alberto, Elli.  We set the green laser doubler crystal temperature to maximise the green laser power output.  The laser diode current was 1.725A and the 1064 laser crystal was 42.05 degrees C.  We varied the doubler crystal temperature and measured the power output.  Attached is a plot of these measurements.  The green laser power was maximised when the doubler crystal temperature was set to 34.37 degrees C.

When the doubler crystal temp was 34.37 degrees C:

(with 1.725A input current, 42.05 degrees C crystal temp)

-The laser power output was measured at 41.9mW

-GR_PWR_MON read 8400 counts

-REFL_PWR_MON read 15500 counts, and we measured 1.22mW, 4.8V, and a gain setting of 20dB at this PD.

The work done on ITMY in the last few days has been duplicated to ETMY. It was very straight forward. The exact same blend filters are being used on both units and provide similar isolation. See attached plot where:

- Red curve is ITMY, BSC-ISI control off  
- Blue curve is ETMY, BSC-ISI control off
- Green curve is ITMY, BSC-ISI control on
- Brown curve is ETMY, BSC-ISI control on   


The data can be found in the DTT file seismic/BSC-ISI/H2/ETMY/Data/Spectra/Isolated/ETMY

Contol off: UTC time 23:52:36, 15 averages, df=50mHz
Contol on:  UTC time 23:45:51, 15 averages, df=50mHz



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

For our records, I am posting the details of what was done to implement this on ETMY:


1) Damping Loops

Our Damping loops were DC coupled. A DC offset was visible when turning the loops on. I added:
- two zeros at DC
- two poles at 25 mhZ: pair(0.025,65)

To do that:
- I modified the cutoff filters in Step_5_Damping_Loops_ST2_LHO_ISI_BSC6.m
- Run Step_6_Damping_Loops_ST1_LHO_ISI_BSC6.m
- Run Step_7_C2D_Damping_Filters_LHO_ISI_BSC6.m
- Updated the foton file


2) Output Filters

Installed the new output filters, which includes the low pass at high frequency to limit the "glitches" when the control is turned ON.

For that:
- Run aLIGO_BSC_ISI_Output_Filters.m
- Run aLIGO_BSC_ISI_Filters_Digitalization.m
- Updated the foton file


3) Blend Filters

- Created the following folders:
/ligo/svncommon/SeiSVN/seismic/BSC-ISI/H2/ETMY/Scripts/Complementary_Filters
/ligo/svncommon/SeiSVN/seismic/BSC-ISI/H2/ETMY/Filters/Complementary

- In Complementary_Filters, copied the ITMY complementary filters file:

Complementary_Filters_Stage12_750mHz_2012_07_25.m
Complementary_Filters_Stage12_250mHz_2012_07_25.m
Complementary_Filters_Stage1_100mHz_2012_07_25.m

Run these three files that create the complementary filters, store them in .mat files saved in Filters/complementary.


4) Control_Scripts

Step_8_Blend_Filters_LHO_ISI_BSC6.m:
- Modified Step_8 to load the good complementary filters
- line 41 and 42 modified the blend_frequency value and index (commented the changes in the m file)


Step_9_C2D_Blend_Filters_LHO_ISI_BSC6.m:
- added teh continuous/digital filters comparison
- modified it to generate the filters necessary to make the blend switching work (T240 and NXT)

Run Step 8 and Step 9 for each of the three blend filters
Updated the foton file

Committed the changes to the svn

 

Jeff K. , Thomas V.

Below are the calibration parameters for the H2 ITMY Optical Lever:
        Slope          Y-intercept
Pitch [ 580.41229822  -11.51774017]
Yaw  [ 689.70532274  -13.3345144 ]


And here are the calibration parameters for the H2 ETMY Optical Lever:
         Slope           Y-intercept 
Pitch [ 1666.80728788   -33.14694715]
Yaw  [ 1727.67131855     23.41350328]

Both sets of calibrations were attained via the same process of moving the QPD along a translation stage and measuring the output signal.  All four sets of slopes are in units of radian*meters.

Optical lever QPD's analog signals from each segment/quadrant come into the ADC in numerical order (1, 2, 3, 4) where the segments are defined as

   +-------+
   | 1 | 3 |  ^
   |---+---|  | This way up
   | 4 | 2 |  |
   +---+---+

(staring at the face of QPD, as though you were an incident laser beam). The QUAD MASTER model absorbs these signals as channels

$(IFO):SUS-$(OPTIC)_L3_OPLEV_SEG1
$(IFO):SUS-$(OPTIC)_L3_OPLEV_SEG2
$(IFO):SUS-$(OPTIC)_L3_OPLEV_SEG3
$(IFO):SUS-$(OPTIC)_L3_OPLEV_SEG4


However, up until this model change, the top level ITMY model had been re-ordering these signals as

Analog Signal    ADC Channel      SEG#
1                1_0              SEG2
2                1_1              SEG1
3                1_2              SEG4
4                1_3              SEG3


I have now re-ordered them in a sane fashion, as the ETMY had already been ordered:

Analog Signal    ADC Channel      SEG#
1                1_0              SEG1
2                1_1              SEG2
3                1_2              SEG3
4                1_3              SEG4


The updated model,
${userapps}/release/sus/h2/models/h1susitmy.mdl
has been committed to the repo, and I've recompiled, reinstalled, restarted, and restored H2SUSITMY.

The Assembly Validation testing of HAM-ISI Unit #6 is complete. HAM-ISI Unit #6 - Assembly Validation report was posted under the DCC, and validated. We can now store this Unit in a container.

HAM-ISI Unit #7 will be the last HAM-ISI built at LHO. Assembly is approching completion. Assembly Validation testing will follow.

Reports regading the Assembly validation of previous units at LHO are available in the DCC:
HAM-ISI Unit #1 - Assembly Validation
HAM-ISI Unit #2 - Assembly Validation
HAM-ISI Unit #3 - Assembly Validation
HAM-ISI Unit #4 - Assembly Validation
HAM-ISI Unit #5 - Assembly Validation

This morning we adjusted the 0.4mm roll out of the MC2 lowest stage via rolling the optic in the sling.  We were able to take the roll error from 0.4mm on each side to 0.003mm error, well within the 0.25mm guideline.

We reset the M3 stage AOSEMs and are now back to running TFs of MC2.

For the record, I've done the following:

  ~ $ cd /opt/rtcds/userapps/release/sus/
sus $ svn up

The "common" folder was what I was specifically looking to make sure was up to date (and now the folder has all the new quad changes, as well as the CD_STATE_MACHINE updates), but the update also received a whole bunch of (other) site specific stuff.

 We received a text message from the alarm handler this morning regarding a signal associated with GV16 at the XMID station. After reviewing the signal in question we realized that this signal had fallen to zero on July 20 from a nominal 1ma  (scale of 1-10 mA)

This looks like the normal failure mode of the annulus ion pump power supply and will be investigated and hopefully repaired (depending on replacement parts) next week.

Signal is HVE-MX:GV16_II339

The tripleteststand had the One-stop cable and cards (between the computer and the I/O chassis) replaced yesterday in an effort to solve the mystery of the models freezing and the cards in the I/O chassis becoming invisible.  The x1sushxts27 model was started Wednesday 7/25 at 14:06 PDT and is still running this morning.  

The END X volume was vented yesterday so work may proceed at BSC9. During turbo pump startup we found that the QDP80 was rotating the wrong way. This was corrected and the turbo was spun up as a precaution.

I started pumping the LVEA vertex volume yesterday.  Roughing was paused overnight and will continue today. Pressure is currently 60  torr.

We looked into the PLL servo. First we checked the temperature feedback signals to the laser. They did seem ok, although the green had a 1mV offset (although not being written to it). We disconnected the green temp feedback.

The IR laser crystal temperature feedback was ok, but only after we managed to reset it to zero. Even the EPICS display was not showing all the digits (we got an intergrator gain of 1e-6). The EPICS screen displays voltage, which is good to know.

We had to adjust the temprature on the laser to find the beatnote, it was set back to 42.1 deg C. The knob on the front panel is very 'coarse', so the beatnote was within 10 MHz from the nominal 39.7 MHz. We engaged the temperature servo and we saw the beatnote move towards the 39.7 MHz. The Phase-Frequency Discriminator has a flat gain when the beatnote is far away from the LO frequency (39.7 MHz). Although not a problem, with low gain you do wait for it:) You can speed it up by engaging the CMB-A servo, which feedback to the PZT. Matter of fact, the temp signal is a plain copy of the PZT signal, which goes through the Beckhoff system and has it sown little servo.

We looked on an oscilloscope at the temperature feedback signal. There are a few ripples in the signal at ~1 micro second, ~5 microseconds and ~2 milli seconds. I think we should add an analog 10 Hz low pass filter at the output to remove these. The temperature feedback has a bandwidth of up ~0.5 Hz anyway.

Looking at the PZT feedback signal. It has ~1.5Vpp 'oscillations' with a ~10s period appearing and then fading away. This is of course the 'equivalent' noise the laser tries to follow. The PZT frequency to volts conversion is ~3 MHz/V, so that indicates that the laser frequency fluctuates by ~4.5 MHz!

Looking a the I-mon from the Phase-Freq Discriminator it is flat when locked (and around the 39.7 MHz). When further away the signal looks like 'pulse-widht-modulated' with an average voltage which correspond to how far away the beatnote is and is expected. I don't know how far the beatnote needs to drift, at which point the frequency discriminator takes over from the phase discriminator. All-in-all the I-mon doesn't seem to be bad or noisy.

We looked into the PLL which seemed to be ok (see other entry 3601). We didn't pay much attention to the RefCav yet, as we want to to make the cavity lock again. To make this happen we had to reset the ETMY HEPI, lucky Fabrice was here to help. The output on ISC BLEND_RZ was off. All is well.

We have fringes again, and the REFL_PWR_MON seems to be at its previous healthy ~11000 counts level. When engaging the cavity locking (CMB-B), it seemed to be ok until is starts the oscillation at 10-20 sec period. I turned the first boost filter off which didn't seem to help much. The VCO frequency drifts upto 39.78 MHz (from 39.603 MHz nominal). It almost looks like there is a sign wrong, it locks, fluctuates around 0 then creeps to the -10V limit. When you look at the VCO frequency it keep slowly climbing. At the same time the cavity power drops. Hmm, maybe still something in the PLL servo is not right.

We have two new indicator on the OAT screen, 'RefCav Trans (V)' and 'Beatnote at (Hz)'. The first one is nominal at 1.1 V (has a green box when above 0.8V, and a red box when <0.4V), and indicates if the RefCav is locked. The Beatnote shows the VCO frequency in Hz, nominal at 39.603 MHz.

I left the cavity unlocked, but the PLL engaged.

A good .snap time is Wed July 25 2012, 20:00h (and half hour from now).

The H2 dust monitor alarm went off. Not sure what button to press, so I pressed silince for one hour ...

I have taken the calibration data and analyzed it. The plot of the linear response curve is attached.

I used a polynomial fitting program in python to get these numbers.  This should give you the conversion from volts to micro-radians.

           Slope            Y-intercept
Pitch   [  1.01902201e+06   8.42886118e+00]
Yaw     [  9.83122943e+05  -1.19329010e+01]

HAM-ISI Unit #6 was balanced, and CPS readouts were within acceptable range, on 07/03 when we left it for long TF measurments. When checked this morning, CPS readouts featured an offset of approximately +/-3000 counts:

There is no drive/offset on MEDM channels.

Coil drivers were turned off. The CPS readouts remained unchanged.

CPS interface chassis were turned off, and then turned back on. The CPS readouts remained unchanged.

Dataviewer plots are attached. They show the drifting of the CPS readouts.

We experienced high temperatures over the last few days.