ETM02A (from BSC10) Removed from SUS to Cake Tin

Cheryl, Chris S. and I went down to Y End TMS lab to get the optic into a cake tin in prep for shipment to KAGRA (eventually). The process went smoothly with no magnet disturbance. We took pix of the optic (which was relatively clean) and the SUS cage. The exposed height adapter plate surface contained what Cheryl called a "forest of fibers": see photo below. Lots of particulate on other horizontal surfaces.

The cake tin is now in the OSB Optics Lab. We removed the SUS cage and the dutch oven from the TMS lab.

Re-calibration of the VCO actuation coefficient

[Kyohei W. and Kiwamu I.]

 There was a concern that the actuation coefficient of the VCO --- which actuates the PSL laser frequency via the refcav for the IMC locking --- were calibrated wrong and hence we might have kept plotting more-or-less inaccurate noise budget. Indeed the coefficient was underestimated by approximately 34% according to a measurement we did today. Giacomo helped us out by confirming that the coefficient had been indeed miscalibrated [1]. Of course this brings our past noise budget of IMC_F slightly higher, but certainly this is not a major issue.
 
 The measured VCO coefficient is 268302 Hz/V (see the attached figure made by Kyohei). Please use this number hereafter.

 A good news is that our measured value agrees with that of Livingston, which is about 246 kHz [2], within 9%. Our measurement was done by applying various DC offset at the input of the VCO box (2-pin lemo) and by looking at the frequency of one of the two outputs with a frequency counter. The input of the VCO box is designed to be a differential input and hence the x-axis of the plot is Vpos-Vneg.

[1] LHO alog #5534 Comments on "IMC noise"
[2] LLO alog #4645 "low range VCO installed"
 

plots of dust counts

Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot requested from 5 PM Feb. 20 to 5 PM Feb 21. Also attached are plots of the modes to show when they were running/acquiring data.

Data was taken from h1nds0.
1440.0 minutes of trend displayed

ALS SHG Temperature controller

The ALS SHG oven is assembled without the crystal and the temperature controlled.  

I added washers between the 5 axis stage and the aluminum base for the ALS SHG, now with the vertical adjustment screws all the way in the crystal is just at four inches.  I think if Bram adds 3 mm to the aluminum base plate for the rest of the units they should have the crystal at 4 inches when the screws are in the center of the adjustment, without any extra washers.  

The temperature controller is working.  The TEC is mounted for this unit in a way that seems upside down when you look at it, the larger face is on top, this requires crossing the wires that drive the TEC.  I did that because the data sheet says that the less wide face of the TEC should be the cool face.  

One last warning about assembling it, I thought I was using a very small amount of thermal paste, but I wish I had used even less.  The thermal paste in the hole for the thermistor was not a problem, but when I lightly tightened the bolt that holds the copper holder in place, the small amount of paste I had on the TEC came oozing out.  I was glad that I did this without the crystal installed.  

The TwinCAT library is called TECController.  Daniel Set up the corner 5 chassis for the third interferometer in end X (really the MSR for now) and there is a PLC called TEST on it.  We configured this system manager to control the TEC, and it is in the SVN at C:SlowControlsTwinCATTargetH1ECATX1H1ECATX1.tsm revision 684

So far none of the variables are in EPICS, but I had a look at the step response using a trend in the TwinCAT visualization.  1 Volt sent towards the TEC raises the temperature by about 18.3 C, and the time constant is roughly 50 seconds.  

The library has a servo, the filter has a pole at zero, a zero at 0.02Hz, and you can adjust the UGF with the user interface.  It seems to work for ugf settings up to 9 Hz, you can push the UGF up to 15 Hz if it is already locked and you aren't changing the temperature, but I don't think that's necessary.  

I will try to post some step responses once we have the channels in EPICS.  

Sheila

Here are some pictures of the SHG temperature controller, with the TEC mounted with the wider side up.  The fig file has some step responses recorded using strip tool, zoomed in on one that is a 1 degree step with the UGF at 5Hz.  The overshoot is around 20% when the ugf is at 5 Hz, and as you can see once things have partially settleded the in loop sensor see fluctuations of less than 0.05 C peak.  
  
The step resposes settings were:
Set Temp   UGF
27         5Hz  (tuning servo on)
29         5Hz
26         5 Hz
28         10 Hz
27         10 Hz
28         7 Hz
27         3Hz
28         3Hz
27         5Hz
28         5Hz    

H1 PR3 Intalled in HAM2

Today, Travis and I (and some Arnaud) used both Genie lifts to move the PR3 from the chamberside work table to the HAM install arm.  With the arm mounted to the NE corner of the chamber, we could not get the PR3 exactly where we wanted it so we had to slide the sus around a bit to locate it in the cookie cutter (we recall hearing that this would be a small issue).  We then found that the safety pins in new HLTS brackets which mount the PR3 to the HAM install arm were very bound up when we tried to deinstall them.  After loosening lots of stuff, we finally got them free and were able to remove the arm from the suspension - we're having the locating pins bored out to a larger clearance since they don't need to be so tight.  We added dog clamps, removed the cookie cutter and will continue with the PRM install tomorrow.

Days Activities

In the morning, the Apollo crew installed "The Arm" on HAM2's East side

9:20  Hugh started work at BSC2 (HEPI Bellows & dial indicator ) & BSC1 (cable strain relief & moving dial indicators); this work went off and on through out the day.

10:15 Rodruck looking for hardware at MY

2:00 Filiberto/Steven modifying EY ISC racks per work permit

Apollo crew

We installed the ham install arm and attached the elevator. Moved a stairway from ham 7 area where it was tested and approved by Jodi and Cheryl for use at ham 2-3. Began assembly of the work platform around bsc 2, several different configurations to choose from (and of course a galled bolt here and there). Will continue the work platform saga tomorrow. ICC at bsc 10 going quite well, brushing complete down to floor and started removing floor to begin brushing below.

Power Spectra for I1-MC2

   I took power spectra for the India HSTS suspension I1-MC2 yesterday. The data files are posted below and have been written to the SVN repository. I will wait for Stuart A. and Jeff K. to review before removing this suspension from the test system.   

WBSC1 at Feed-Thrus Cables Strain Relieved

Strain relieved all the cables coming to the Chamber.  That is, zip tied all cables to the feedthru protection.  I did not unplug any cables and only molested them as required.  SUS & SEI would be wise to check no harm was inflicted.

PR3 Phase 2b passed

Attached are plots of PR3 comparing power spectra from L1 PR3 (June 2012), H1 PR3 (Feb 14th 2013 before Betsy changed the brackets), H1 PR3 (Feb 19th 2013 after changing the brackets), and H1 PR3 (Feb 20th 2013 after recentering M2 UL OSEM and moving one of the top EQ stops).

To sum up, some investigation has been done to understand why some peaks from Feb 13th PR3 power spectra has been shifted in frequency  (see the ~3.2 Hz peak on the red curve for M2 Pitch page 18 on allhltss_2013-02-20_Phase2b_PR3_ALL_Spectra_Doff ). After making few changes as described above, the new power spectra taken yesterday (Feb 20th) look consistent.

PR3 is now ready to get installed in the chamber.

 

BSC10 ICC

Chamber cleaning started on Tuesday, 19 Feb. 
BSC10 has very robust color and staining from the original bake for strain relief. Please see attached PDF for pix.
Note the deep brown/black background color of the chamber, the yellow and orange trails and splotches and other colorful artifacts visible on the chamber’s interior surface. (Upper photos) Some concern has been expressed with regard to the quality of the brushed sections. I inspected progress this morning (21 Feb) and am satisfied that the ICC process is working as intended. Although the results are not as “pretty” or “shiny” as we would like, there is ample evidence that the surface layer is being removed (Lower photos).  Notice the change in surface color to a silver/whitish background and the absence of orange and yellow trails. 

Apollo crew

Yesterdays report! We moved some BSC plates to mid x and a BSC cartdridge container back to the corner station for Hugh. The top section and collar of the BSC 10 chamber was brushed. We installed the stiffener backing ring and o-ring protectors on HAM 2 with the install arm to follow today. 

plots of dust counts

Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot requested from 5 PM Feb. 19 to 5 PM Feb 20. Also attached are plots of the modes to show when they were running/acquiring data.

Data was taken from h1nds0.
1440.0 minutes of trend displayed

PR3 - 2 rounds of noise hunting

The spectra taken since the M2 stage AOSEM bracket swap last Friday (15th) show slightly anomolous peaks (not glaringly wrong, but not great).  This morning we attempted to remedy the mis-centering of the M1 UL AOSEM which we thought might be brushing the magnet.  After deeming it ok, Arnaud's spectra revealed it still to be bad.  This time I went in and played with both the UL and LL attempting to center the AOEM with it buried over the magnet blocking all of the light.  This old standby technique was not very helpful though because as you draw the AOSEM back out to 50% open light, the AOSEM walks all over in the bracket nulling the alignment.  The stackup of brackets at this stage are not very nice (putting it nicely).

The picture below shows how all 4 AOSEM brackets are crooked relative to the structure and the suspended mass with the "modified" brackets.  We needed to make new brackets here.  Too late.  (Although I have Tyler making a fresh set for SR3, now that I am aware of the problem.)

I also found that one of the 4 top mass EQ stops was brushing the top mass.  This could have been the culprit the whole time, but nevertheless, the M2 stage brackets don't look right.

PRM unplugged and ready for transport to HAM2

Yesterday, Travis did this.  PR3 is the first one we need, however but it's good to get this work done.

Ops review

- 8:15 meeting Richard mention alarm ITMY OSEM3 was on

- 10:00 Filiberto shut down ITMY electronics - turned on at 12:00, followed by oscillation on OSEM5 and OSEM6, solved by Pele and Mark

- 11:30 Patrick activated DUST monitor 9

Yesterday, I powered down the ITMY coil drivers. I disconnected and reconnected field cables at the SAT units inside SUS H1-R6. This was done to help finish dressing cabling inside the rack. When units were reconnected and powered up, we saw a high frequency oscillation as described by Pablo. We were able to remove the oscillation by power cycling the AA units.

Inspection in HAM2:

Jodi and I inspected HAM2 withness plates and surfaces, and found a lot of articulate.  Wafers also have visible finger prints, that I put there installing them - good reason to use our nifty wafer tweezers.  Particulate found on all wafers.  Examples include but are not limited to white fibers, black flecks, white flecks, metal flecks, bright red stuff, and a bit of First Contact.

- Jodi, Cheryl

Observations of witness plates and other in-chamber surfaces goes as follows:

Every surface we looked at had particulate, including table top, optic structures, etc.  Optics, both small fixed 2" and the larger 4" IM2 and IM4, show particulate.

Witness Plates:

- Worst contamination: 
One 4" witness plate on the HAM2 table top:
Exposed during IO installation, pump down and vent.  
Significant particulate, and my gloved hand print.

- Competing for the next worst contamination:
Two 4" witness plates in the beam tube, North and South of HAM2:
Exposed during pump down and vent.  
Large particulate easily seen from about 1.5m away.

Two 4" witness plates in the bottom of HAM2:
Exposed during pump down and vent.  
Large particulate easily seen from about 1.5m away.

- The winners, showing the least contamination:
4" witness plates in the beam tube, West side of HAM2 on ISI level-0, positioned North, Center, and South:
Exposed during pump down and vent.  
Small particulate easily seen by eye.

- The three 1 optics had some particulate but were very hard to evaluate in-chamber, so hard to say how much contamination is on their surfaces until we can pick them up.  There was a piece of First Contact, about 1mm square, on one of the 3 optics - it was missed by at least two sets of eyes before pump down.  The up-side is that this does show that FC stayed put on an optic during pump down and venting.

Current State of Witness Plates in HAM2:
We did not have containers to remove wafers or 1" optics, so new wafers were installed along side the old wafers, (in every position, the new wafer is installed in the counter-clockwise direction from the old wafer).  Two new wafers replaced the old table top wafer, and the old wafer was moved across the table, to prevent it from contaminating the new wafers.

B&K Hammer Measurement

Arnaud P. Betsy W. 

Did B&K hammer measurements on Friday feb 8th on the BeamSplitter that will be installed in BSC2. 
Config: BSC-ISI Unlocked, QUAD Unlocked, Baffles ON, Vibration Absorbers ON, Damping ON.

Attached, pictures describing the position of hammer impacts, and accelerometer + corresponding pulse files.

Raw data has been exported from the B&K Pulse files, in accordance with the procedure outlined in the SUS Operations Manual (see How to do B&K Hammer Testing).

Exported ASCII data files have been committed to the SUS svn at the following location, ligo/svncommon/SusSVN/sus/trunk/BSFM/H1/BS/BandK$, these files include the following (n.b. files have been renamed to comply with convention detailed in the Op's Manual) :-

SimpleHammerDisplay3-BS-Bottom-SUSunlocked-ISIunlocked-VAfitted-Yimpact.pls
SimpleHammerDisplay3-BS-Bottom-SUSunlocked-ISIunlocked-VAfitted-Yimpact.txt
SimpleHammerDisplay3-BS-BottomLeft-SUSunlocked-ISIunlocked-VAfitted-Ximpact.pls
SimpleHammerDisplay3-BS-BottomLeft-SUSunlocked-ISIunlocked-VAfitted-Ximpact.txt
SimpleHammerDisplay3-BS-BottomRight-SUSunlocked-ISIunlocked-VAfitted-Ximpact.pls
SimpleHammerDisplay3-BS-BottomRight-SUSunlocked-ISIunlocked-VAfitted-Ximpact.txt
SimpleHammerDisplay3-BS-TopLeft-SUSunlocked-ISIunlocked-VAfitted-Ximpact.pls
SimpleHammerDisplay3-BS-TopLeft-SUSunlocked-ISIunlocked-VAfitted-Ximpact.txt
SimpleHammerDisplay3-BS-TopLeft-SUSunlocked-ISIunlocked-VAfitted-Yimpact.pls
SimpleHammerDisplay3-BS-TopLeft-SUSunlocked-ISIunlocked-VAfitted-Yimpact.txt
SimpleHammerDisplay3-BS-TopMiddle-SUSunlocked-ISIunlocked-VAfitted-Ximpact.pls
SimpleHammerDisplay3-BS-TopMiddle-SUSunlocked-ISIunlocked-VAfitted-Ximpact.txt
SimpleHammerDisplay3-BS-TopMiddle-SUSunlocked-ISIunlocked-VAfitted-Yimpact.pls
SimpleHammerDisplay3-BS-TopMiddle-SUSunlocked-ISIunlocked-VAfitted-Yimpact.txt
SimpleHammerDisplay3-BS-TopRight-SUSunlocked-ISIunlocked-VAfitted-Ximpact.pls
SimpleHammerDisplay3-BS-TopRight-SUSunlocked-ISIunlocked-VAfitted-Ximpact.txt
SimpleHammerDisplay3-BS-TopRight-SUSunlocked-ISIunlocked-VAfitted-Yimpact.pls
SimpleHammerDisplay3-BS-TopRight-SUSunlocked-ISIunlocked-VAfitted-Yimpact.txt

The above B&K data has been processed using v12 of the "BandK_plot.m" Matlab script, available in the /ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools$ directory.

The merged plot attached below shows:-
pg1 - Y response of the structure to Y hammer impact excitations at various locations, from 1Hz to 400Hz.
pg2 - X response of the structure to X hammer impact excitations at various locations, from 1Hz to 400Hz.
pg3 - X response of the structure to X hammer impact excitations at various locations, ZOOMED IN from 50Hz to 400Hz.

n.b. hammer impact locations are viewable in the attachment to the original aLOG entry above see "Hammer_Impacts.pdf".   

IMC pole measurement

[Rodica, Kiwamu, Dick, Michael R., Keita, Paul]

Last night and today we finally managed to get what looked like a good measurement of the IMC pole response. Here is a brief description of the measurement setup:

Swept sine signal applied directly from the SRS785 to the AOM driver box inside the PSL. Frequency range was 1kHz to 100kHz, signal amplitude was 400mV pkpk. 1000 intergration cycles, and 101.56ms integration time. Measurement was a transfer function from the DCPD on the PSL installed recently (PDA55) to the DCPD on the IOT2L table (DET100A). ~200mW injected to modecleaner.

The PDA55 on the PSL table didn't give us an observable signal from the amplitude modulation previously when we tried on Wednesday. Rodica checked the Thorlabs recommendation for best linear performance, which states that the maximum intensity should be less than 10mW/cm^2. Even with a very low beam power we may have been exceeding this value due to the very small beam size. The PD was therefore moved to have a larger incident beam size.

We were struggling to get a decent signal on the SRS785 until Kiwamu suggested reducing the light power reaching the PDs to less than 1V. Once we brought the power down to less than 600mV, we were able to see a decent signals on the SRS785 and began taking TFs. 

The first attached transfer function is directly from the PSL PD to the IOT2L PD. In the event that the response of both PDs is linear, this should just give the cavity response. However, we noticed that the phase dropped below -90deg on the TF, indicating the presence of another pole - likely that of one of the PDs. We therefore took a TF from the PSL PD to the IOT2L PD, with the IOT2L PD repositioned in the IMC REFL path and the cavity misaligned (as Giacomo did previously). This TF is the second attached plot, and shows the pole of the IOT2L PD. Finally, we then divided the first transfer function by the second to eliminate the different PD response, leaving us just with the cavity response. This transfer function, along with a fit, is shown in the third attached plot.

For now, I just fitted the phase of the pole measurement, which gave the result 8812.36 Hz for the cavity pole. I'll try a complex data fitting routine soon and post the result.

IMC noise

Attached is a plot of the calibrated IMC control signals for the following relevant control loop settings:

- Common Mode Board: common gain = 20 db, compensation and 1st common boost on, fast gain = -2 db.

- MC2_M3_LOCK_L filters: gain -1000, FM5 (150:4) and FM8 (CLP100) enabled, limt to 400k.

- MC2_M2_LOCK_L filters: gain = 0.03, FM1 (0.01:0.1), FM2 (0.03:1), FM3 (Stab8:2), FM4 (300:1) and FM10 (ELF80) enabled, limit to 300k.

 

The signals have been calibrated following L1 example. Details on the calibration follow (both for clarity and to check that I correctly interpreted what they has been done at L1).

---- IMC_F ----

- The fast path control signal is directly acquired from the Common Mode Board and becomes the input to the H1IMC-F filter bank (H1:IMC_F_INMON)

- the filter bank contains the following (enabled) filters:

   - "cts2V" that converts ADC counts in volts (0.000610016 V/ct)

   - "InvGenFilt" that compensates for the withening filter at the output of the Common Mode Board (double pole at 10 Hz, double zero at 100 Hz, DC gain = 0.5)

   - "VCO" that accounts for the VCO DC gain (365714 Hz/V, obtained from the test report of unit D0900605-S1200558 and multiplied by 2 to account for the AOM double pass) and filter (pole at 1.6 Hz, zero at 40 Hz)

   - "FtoL" (I added this at H1) that converts the frequency variations dF into equivalent modecleaner round-trip variations dL using dL = dF * L * lambda / c, where L is the length of the IMC (16.47 m nominal), lambda = 1064e-9 m, c=3*10^8 m/s.

 

---- IMC_X ----

- the output of the MC2_[M3/M2]_LOCK_L filters are input in the IMC-X_[M2/M3] filters bank, respectively

- the MC3 filter bank contains the following enabled filters:

   - "dc_cal" that converts the length actuation into mass displacement at DC

   - "sus_d" that accounts for the TF from force on M3 to displacement of M3 (rescaled for 0 dB DC gain because of the existence of "dc_cal"). Note that this TF has been calculated for L1 in the case of velocity damping; although we are still using velocity damping here at H1, it need to be verified that we are using the same setting that L1 was using when the TF was calculated.

   - "white", a whitening filter (two 0.2 Hz poles and two 1000 Hz zeros) used to get rid of digitization noise. It need to be tken into account when analyzing data.

- the MC2 filter bank contains similar filters, except that "sus_d" is replaced by the combination of "sus_d1" an "sus_d2", that account for the TF from force on M2 to displacement of M3.

- the outputs of both filter banks are summed to estimate the actual M3 motion.