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  Coating Ring-down Measurement Lab elog, Page 10 of 18  Not logged in ELOG logo
ID Date Author Type Category Subject
  431   Thu Sep 21 12:49:44 2017 GabrieleGeneralMeasurementsS1600569 S1600570 S1600571 S1600572

2017-09-21

  • 12:30pm, in chamber
    • S1600569 in CR1
    • S1600570 in CR2
    • S1600571 in CR3
    • S1600572 in CR4
  • 12:35am roughing pump on
  • 12:49am turbo pump on
  • Excitations
    • Quiet time before excitation: 1190073038
      Excitation broadband: 1190073073
      Quiet time after excitation: 1190073098

    • Quiet time before excitation: 1190080329
      Excitation broadband: 1190080364
      Quiet time after excitation: 1190080389

    • Quiet time before excitation: 1190087619
      Excitation broadband: 1190087654
      Quiet time after excitation: 1190087679

    • Quiet time before excitation: 1190094909
      Excitation broadband: 1190094944
      Quiet time after excitation: 1190094969

    • Quiet time before excitation: 1190102199
      Excitation broadband: 1190102235
      Quiet time after excitation: 1190102260

    • Quiet time before excitation: 1190109490
      Excitation broadband: 1190109525
      Quiet time after excitation: 1190109550

  • More excitations
    • Quiet time before excitation: 1190128992
      Excitation broadband: 1190129027
      Quiet time after excitation: 1190129052
    • Quiet time before excitation: 1190136282
      Excitation broadband: 1190136317
      Quiet time after excitation: 1190136342
    • Quiet time before excitation: 1190143572
      Excitation broadband: 1190143607
      Quiet time after excitation: 1190143632
    • Quiet time before excitation: 1190150862
      Excitation broadband: 1190150897
      Quiet time after excitation: 1190150922
    • Quiet time before excitation: 1190158152
      Excitation broadband: 1190158187
      Quiet time after excitation: 1190158212
    • Quiet time before excitation: 1190165442
      Excitation broadband: 1190165477
      Quiet time after excitation: 1190165502

 

 

  430   Thu Sep 14 15:59:10 2017 GabrieleFacility All wrapped up for Saturday plumbing work



 

  429   Wed Sep 13 10:17:22 2017 GabrieleGeneralMeasurementsS1600563 S1600564

2017-09-13

  • 10:00am in chamber
    • S1600563 in CR1
    • S1600564 in CR2
  • 10:12am roughing pump on
  • 10:20am turbo pump on
  • Excitations
    • Quiet time before excitation: 1189372632
      Excitation broadband: 1189372668
      Quiet time after excitation: 1189372693

    • Quiet time before excitation: 1189379923
      Excitation broadband: 1189379958
      Quiet time after excitation: 1189379983

    • Quiet time before excitation: 1189387213
      Excitation broadband: 1189387248
      Quiet time after excitation: 1189387273

    • Quiet time before excitation: 1189394503
      Excitation broadband: 1189394538
      Quiet time after excitation: 1189394563

    • Quiet time before excitation: 1189401793
      Excitation broadband: 1189401828
      Quiet time after excitation: 1189401853

    • Quiet time before excitation: 1189409083
      Excitation broadband: 1189409118
      Quiet time after excitation: 1189409143

  428   Tue Sep 12 09:58:45 2017 GabrieleGeneralMeasurementsS1600565 S1600566 S1600567 S1600568

2017-09-12

  • 9:45am, in chamber
    • S1600565 in CR1
    • S1600566 in CR2
    • S1600567 in CR3
    • S1600568 in CR4
  • 9:47am roughing pump on
  • 9:58am turbo pump on
  • Excitations:
    • Quiet time before excitation: 1189284835
      Excitation broadband: 1189284870
      Quiet time after excitation: 1189284895

    • Quiet time before excitation: 1189292125
      Excitation broadband: 1189292160
      Quiet time after excitation: 1189292185

    • Quiet time before excitation: 1189299415
      Excitation broadband: 1189299450
      Quiet time after excitation: 1189299475

    • Quiet time before excitation: 1189306705
      Excitation broadband: 1189306740
      Quiet time after excitation: 1189306765

    • Quiet time before excitation: 1189313995
      Excitation broadband: 1189314030
      Quiet time after excitation: 1189314055

    • Quiet time before excitation: 1189321285
      Excitation broadband: 1189321320
      Quiet time after excitation: 1189321345

2017-09-13

  • 9:50am valve closed, pumps stopped, venting
  427   Mon Sep 11 11:01:02 2017 GabrieleGeneralMeasurementsS1600561 S1600562 S1600563 S1600564

2017-09-11

  • 10:50am in chamber
    • S1600561 in CR1
    • S1600562 in CR2
    • S1600563 in CR3
    • S1600564 in CR4
  • 10:51am roughing pump on
  • 11:01am turbo pump on
  • Excitations
    • Quiet time before excitation: 1189209951
      Excitation broadband: 1189209986
      Quiet time after excitation: 1189210011

    • Quiet time before excitation: 1189217241
      Excitation broadband: 1189217276
      Quiet time after excitation: 1189217301

    • Quiet time before excitation: 1189224531
      Excitation broadband: 1189224566
      Quiet time after excitation: 1189224591

    • Quiet time before excitation: 1189231821
      Excitation broadband: 1189231856
      Quiet time after excitation: 1189231881

    • Quiet time before excitation: 1189239111
      Excitation broadband: 1189239146
      Quiet time after excitation: 1189239171

    • Quiet time before excitation: 1189246401
      Excitation broadband: 1189246436
      Quiet time after excitation: 1189246461

2017-09-12

  • 9:30am valve closed, pumps stopped, venting
  426   Tue Sep 5 11:11:39 2017 GabrieleGeneralMeasurementsS1600551 S1600552 LMA_substrate

2017-09-05

  • 11:00am in chamber
    • S1600551 in CR1
    • S1600552 in CR2
    • LMA substrate (CO2 polished) in CR3
  • 11:05am roughing pump on
  • 11:15am turbo pump on
  • Excitations:
    • Quiet time before excitation: 1188691872
      Excitation broadband: 1188691907
      Quiet time after excitation: 1188691932

    • Quiet time before excitation: 1188699162
      Excitation broadband: 1188699197
      Quiet time after excitation: 1188699222

    • Quiet time before excitation: 1188706452
      Excitation broadband: 1188706487
      Quiet time after excitation: 1188706512

    • Quiet time before excitation: 1188713742
      Excitation broadband: 1188713777
      Quiet time after excitation: 1188713802

    • Quiet time before excitation: 1188721032
      Excitation broadband: 1188721067
      Quiet time after excitation: 1188721092

2017-09-11

  • 10:37am, pumps topped, valve closed, venting
  425   Fri Aug 25 19:29:07 2017 GabrieleGeneralMeasurementsExcitations with new ESD

New set of excitations after raising the ESD:

  • Quiet time before excitation: 1187676942
    Excitation broadband: 1187676974
    Quiet time after excitation: 1187676996
  • Quiet time before excitation: 1187684226
    Excitation broadband: 1187684258
    Quiet time after excitation: 1187684280
  • Quiet time before excitation: 1187691510
    Excitation broadband: 1187691542
    Quiet time after excitation: 1187691564
  • Quiet time before excitation: 1187698794
    Excitation broadband: 1187698826
    Quiet time after excitation: 1187698848

Q values are now reasonable

Quote:

The results show very low Q values, so we suspected some issues. Yesterday we openend the chamber and moved the ESD up, as high as possible. New excitation followed:

  • Quiet time before excitation: 1187676942
    Excitation broadband: 1187676974
    Quiet time after excitation: 1187676996

  • Quiet time before excitation: 1187684226
    Excitation broadband: 1187684258
    Quiet time after excitation: 1187684280

  • Quiet time before excitation: 1187691510
    Excitation broadband: 1187691542
    Quiet time after excitation: 1187691564

  • Quiet time before excitation: 1187698794
    Excitation broadband: 1187698826
    Quiet time after excitation: 1187698848
     

     

Quote:

2017-08-23

  • Excitations
    • Quiet time before excitation: 1187577794
      Excitation broadband: 1187577826
      Quiet time after excitation: 1187577848

    • Quiet time before excitation: 1187585078
      Excitation broadband: 1187585111
      Quiet time after excitation: 1187585133

    • Quiet time before excitation: 1187592363
      Excitation broadband: 1187592395
      Quiet time after excitation: 1187592417

    • Quiet time before excitation: 1187599647
      Excitation broadband: 1187599679
      Quiet time after excitation: 1187599701

    • Quiet time before excitation: 1187606931
      Excitation broadband: 1187606964
      Quiet time after excitation: 1187606986

    • Quiet time before excitation: 1187614217
      Excitation broadband: 1187614249
      Quiet time after excitation: 1187614271

 

 

  424   Fri Aug 25 07:25:32 2017 GabrieleGeneralMeasurementsExcitations with new ESD

The results show very low Q values, so we suspected some issues. Yesterday we openend the chamber and moved the ESD up, as high as possible. New excitation followed:

  • Quiet time before excitation: 1187676942
    Excitation broadband: 1187676974
    Quiet time after excitation: 1187676996

  • Quiet time before excitation: 1187684226
    Excitation broadband: 1187684258
    Quiet time after excitation: 1187684280

  • Quiet time before excitation: 1187691510
    Excitation broadband: 1187691542
    Quiet time after excitation: 1187691564

  • Quiet time before excitation: 1187698794
    Excitation broadband: 1187698826
    Quiet time after excitation: 1187698848
     

     

Quote:

2017-08-23

  • Excitations
    • Quiet time before excitation: 1187577794
      Excitation broadband: 1187577826
      Quiet time after excitation: 1187577848

    • Quiet time before excitation: 1187585078
      Excitation broadband: 1187585111
      Quiet time after excitation: 1187585133

    • Quiet time before excitation: 1187592363
      Excitation broadband: 1187592395
      Quiet time after excitation: 1187592417

    • Quiet time before excitation: 1187599647
      Excitation broadband: 1187599679
      Quiet time after excitation: 1187599701

    • Quiet time before excitation: 1187606931
      Excitation broadband: 1187606964
      Quiet time after excitation: 1187606986

    • Quiet time before excitation: 1187614217
      Excitation broadband: 1187614249
      Quiet time after excitation: 1187614271

 

  423   Thu Aug 24 14:15:45 2017 GabrieleGeneralMeasurementsS1600525 S1600530 S1600532 S1600533

2017-08-24

  • 2:13pm in chamber
    • S1600525 in CR1
    • S1600530 in CR2
    • S1600532 in CR3
    • S1600533 in CR4
  • 2:15pm roughing pump on
  • 2:23pm turbo pump on
  • Excitation
    • Quiet time before excitation: 1187662248
      Excitation broadband: 1187662284
      Quiet time after excitation: 1187662308

    • Quiet time before excitation: 1187664138
      Excitation broadband: 1187664173
      Quiet time after excitation: 1187664198

    • Quiet time before excitation: 1187666028
      Excitation broadband: 1187666063
      Quiet time after excitation: 1187666088

    • Quiet time before excitation: 1187667918
      Excitation broadband: 1187667953
      Quiet time after excitation: 1187667978

    • Quiet time before excitation: 1187669809
      Excitation broadband: 1187669844
      Quiet time after excitation: 1187669869

    • Quiet time before excitation: 1187671699
      Excitation broadband: 1187671734
      Quiet time after excitation: 1187671759

    • Quiet time before excitation: 1187673589
      Excitation broadband: 1187673624
      Quiet time after excitation: 1187673649

    • Quiet time before excitation: 1187675479
      Excitation broadband: 1187675514
      Quiet time after excitation: 1187675539

  422   Thu Aug 24 07:40:33 2017 GabrieleGeneralMeasurementsExcitations with new ESD

2017-08-23

  • Excitations
    • Quiet time before excitation: 1187577794
      Excitation broadband: 1187577826
      Quiet time after excitation: 1187577848

    • Quiet time before excitation: 1187585078
      Excitation broadband: 1187585111
      Quiet time after excitation: 1187585133

    • Quiet time before excitation: 1187592363
      Excitation broadband: 1187592395
      Quiet time after excitation: 1187592417

    • Quiet time before excitation: 1187599647
      Excitation broadband: 1187599679
      Quiet time after excitation: 1187599701

    • Quiet time before excitation: 1187606931
      Excitation broadband: 1187606964
      Quiet time after excitation: 1187606986

    • Quiet time before excitation: 1187614217
      Excitation broadband: 1187614249
      Quiet time after excitation: 1187614271

  421   Wed Aug 23 14:11:13 2017 Zach, GabrieleElectronicsMeasurementsInstalling ESD Prototype

2017-08-23

  • Installed ESD Prototype design by taping it to the older design, we then lowered the mount until it was as close as we could reasonably get it. The new PCB lines up when the top of the new PCB is lined up with the last electrode on the old one. The new PCB was slightly too narrow, the mounting holes are very close to the edge of the PCB, this can easily be corrected in later models.
  • Installed sample S1600541 into the single sample apparatus
  • Roughing pump on at 12:32
  • Turbo pump on at 2:28pm

Link to image1.JPG Link to image2.JPG

Attachment 1: image1.JPG
image1.JPG
Attachment 2: image2.JPG
image2.JPG
  420   Fri Aug 18 15:10:23 2017 Zach, GabrieleElectronicsModelingESD prototype

2017-08-18

  • We created a prototype of PCB for the ESD design. Unfortunately the orientation of the two combs was flipped, so it will require some creative mounting to get right. The final design had a 6 mm offset between the two combs, .5 mm traces and 1 mm gaps between them The vertical traces are 12 mm long and there is a 3.75 mm gap between the end of the vertical traces and the opposite horizontal one. The ESD will arrive on Tuesday to be installed Wednesday and we will see how the new design works out.

 

Attachment 1: Crime_ESD_Zach_prototype.pdf
Crime_ESD_Zach_prototype.pdf
  419   Fri Aug 18 14:15:47 2017 ZachElectronicsModelingSame Voltage ESD Sweep

2017-08-18

  • I ran a sweep of the central position in the two ESD setup with both set at the same voltage. There were two designs that maximized excitation by different metrics, the design with a 3 mm shift from the original design maximized excitation overall, but the 20 kHz mode was worse by a bout a factor of 5. The design with a -2 mm shift maximized the high frequency modes, particularly the modes most affected by the shift.
  • MATLAB crashed shortly after the sweep so I will have to recreate the RMS plots of the dynamic modes later.

 

Attachment 1: two_positive_ratio_sweep.pdf
two_positive_ratio_sweep.pdf
Attachment 2: -2mm_two_positive.jpg
-2mm_two_positive.jpg
  418   Fri Aug 18 14:05:36 2017 GabrieleGeneralComputersWorkstation is now up

Reinstalled Debian 8, all packages and CDS software.

Everything seems to be working fine now.

Quote:

While I was working, the network connection went down. I tried to reboot the workstation, but I won't boot anymore.

  • First issue: firmware of network card disappeared. I managed to download it on a USB stick and install it back
  • Second issue: mismatch of NVIDIA graphic card drivers and kernel. Can't start X

Working on it...

 

  417   Fri Aug 18 10:50:53 2017 ZachElectronicsModelingESD's with positive voltage

2017-08-18

  • With both electrodes driven at a positive voltage, the results are still an improvement over the original design, but by smaller factors, particularly in 3 of the higher frequency modes at around 2 and 3 kHz. With another parametric sweep I may be able to find a better design. The opposite voltage was useful because it could couple force in opposite directions to adjacent anti-nodes with opposing signs. An adjusted configuration could probably be found to interact with anti nodes with the same signs. An alternative option would be to leave the radial position of the more central ESD constant but rotate it relative to the sample by some amount, though this would also require an additional parametric sweep as well as a much larger ESD. 

  416   Thu Aug 17 23:34:51 2017 ZachElectronicsModelingOptimized ESD Drawing

2017-08-17

  • I made a drawing of the Optimal ESD design. The bottom combs (right hand in the rotated image) are set to ground and the 5 arm comb is set to a positive voltage and the 2 arm comb is set to a negative voltage. 

Attachment 1: OptimizedESD.pdf
OptimizedESD.pdf
  415   Thu Aug 17 14:19:04 2017 ZachElectronicsModelingTwo ESD Optimization

2017-08-17

  • I ran a sweep of the position of the middle ESD to determine the optimal arrangement. From the original geometry I offset the central ESD between -2 mm and 11 mm. From the plots below I conclude that the optimal geometry is the one that is shifted 2 mm to the right of the original design. 
  • The first plot is the sweep data as a ratio to the data of the current geometry for all modes. The second plot is the root mean square of the eight high frequency modes that change the most over the course of the sweep, those are modes 9, 11, 13, 14, and 17-20. The frequencies of those modes in order are 9.5kHz, 11 kHz, 14 kHz, 16 kHz, 19 kHz, 20 kHz, 21 kHz, and 23 kHz. There is a very apparent peak at 2 mm which is the driving force behind my conclusion that it is the optimal design. The next two plots are the 2mm shifted design and the original design as ratios to the original geometry. The 2mm shifted geometry is much more consistent than the original design, there is a very noticeable minimum in the original design (improvement by a factor of 2) for the 23 kHz mode that is resolved in the shifted design to a factor of 9.
  • The final plot are ratios of the two designs relative to each other. I found this plot useful to convince myself that the 2 mm shifted design was better than the original, particularly in the region above 1.5 kHz.

Attachment 1: Two.jpg
Two.jpg
Attachment 2: Two.jpg
Two.jpg
Attachment 3: RMS.jpg
RMS.jpg
Attachment 4: 2mm_shifted.jpg
2mm_shifted.jpg
Attachment 5: Sweep_Ratio.jpg
Sweep_Ratio.jpg
Attachment 6: Dynamic_Modes.jpg
Dynamic_Modes.jpg
Attachment 7: Sweep_Ratio.jpg
Sweep_Ratio.jpg
Attachment 8: Comparing.jpg
Comparing.jpg
Attachment 9: 0mm_shifted.jpg
0mm_shifted.jpg
Attachment 10: Comparing.jpg
Comparing.jpg
Attachment 11: 0mm_shifted.jpg
0mm_shifted.jpg
Attachment 13: 2.Dynamic_Modes.jpg
2.Dynamic_Modes.jpg
  414   Wed Aug 16 16:05:09 2017 ZachElectronicsModelingTwo ESD First test

2017-08-16

  • I created a model with two ESD's, essentially a combination of my previous two attempts with one ESD on the edge and one closer to the center of the disk. This test was quite successful compared to previous trials, the improvement seems to be on an average of a factor of 10. No modes are weakened by this design. I am going to run a sweep adjusting the central ESD and see what placement is best.
  • Attached is an overlay of the force profile and all of the modes. Note that this image is very large, and is useful as a digital reference or very large print only.

  413   Wed Aug 16 14:35:05 2017 GabrieleGeneralComputersWorkstation is down

While I was working, the network connection went down. I tried to reboot the workstation, but I won't boot anymore.

  • First issue: firmware of network card disappeared. I managed to download it on a USB stick and install it back
  • Second issue: mismatch of NVIDIA graphic card drivers and kernel. Can't start X

Working on it...

  412   Wed Aug 16 11:36:13 2017 ZachElectronicsModelingMiddle ESD

2017-08-16

  • I created a model with a drive offset in the middle. It improved one of the modes by a factor of 14 or so, but overall, it diminished the vast majority of the modes by as much as a factor of 100. 

Attachment 2: overlay23.jpg
overlay23.jpg
  411   Wed Aug 16 10:04:24 2017 ZachElectronicsModelingESD along edge

2017-08-16

  • I placed created a very narrow ESD placed along the edge of the sample. The thought behind this is that it will not cross over into any other modes that will cancel out the force. However, it does not appear to couple force into enough of the area of the disk to cause a worthwhile improvement, as can be seen in the plot, more modes lost amplitude than gained and some were worse by as much as a factor of 1000.

Attachment 2: overlay15.jpg
overlay15.jpg
  410   Wed Aug 16 09:05:23 2017 GabrieleGeneralMeasurementsS1600539 S1600547 S1600548 S1600550

2017-08-16

  • 8:55am in chamber
    • S1600539 in CR1
    • S1600547 in CR2
    • S1600548 in CR3
    • S1600550 in CR4
  • 8:57am roughing pump on
  • 9:06am turbo pump on
  • 10:10am pressure stuck at 1.8e-3, although the turbo pump was running
    • stopped pumps, opened the chamber, closed again
  • 12:15am roughing pump on
  • 12:22am turbo pump on

The vacuum issue was only a problem with the CG gauge reading 1.8e-3 as minimu, and the IGM didn't switch on because of the overpressure control. Alena fixed the configuration.

  • Excitations:
    • Quiet time before excitation: 1187132177
      Excitation broadband: 1187132212
      Quiet time after excitation: 1187132237

    • Quiet time before excitation: 1187134067
      Excitation broadband: 1187134102
      Quiet time after excitation: 1187134127

    • Quiet time before excitation: 1187135957
      Excitation broadband: 1187135992
      Quiet time after excitation: 1187136017

    • Quiet time before excitation: 1187137847
      Excitation broadband: 1187137882
      Quiet time after excitation: 1187137907

    • Quiet time before excitation: 1187139737
      Excitation broadband: 1187139772
      Quiet time after excitation: 1187139797

    • Quiet time before excitation: 1187141627
      Excitation broadband: 1187141662
      Quiet time after excitation: 1187141687

    • Quiet time before excitation: 1187143517
      Excitation broadband: 1187143553
      Quiet time after excitation: 1187143578

    • Quiet time before excitation: 1187145408
      Excitation broadband: 1187145443
      Quiet time after excitation: 1187145468

  409   Tue Aug 15 16:43:58 2017 ZachElectronicsModelingUnchanged Mode Insight

2017-08-15

  • It appears to me that the major factor limiting the improvement of the modes that either remain equal or diminish is that the original design was already quite good at exciting those modes. As can be seen in the attached plots, the original design is about as well centered over the 5 modes as a rectangle on the x axis can be. As a result, maintaing a constant potential on the ESD it would be difficult to improve the coupled force without specifically tailoring the force profile to a certain mode.
  • In order from left to right, the frequencies of the given modes are 14.2 kHz, 16.2 kHz, 16.3 kHz, 23.8 kHz, and 27.4 kHz.

Attachment 1: Double.pdf
Double.pdf
Attachment 2: Thin.pdf
Thin.pdf
Attachment 3: Original.pdf
Original.pdf
  408   Tue Aug 15 10:24:44 2017 GabrieleGeneralMeasurementsS1600535, S1600536, S1600537, S1600538

2017-08-15

  • 10:16am in chamber
    • S1600535 in CR1
    • S1600536 in CR2
    • S1600537 in CR3
    • S1600538 in CR4
  • 10:17am roughing pump on
  • 10:25am turbo pump on
  • Excitations
    • Quiet time before excitation: 1186867153
      Excitation broadband: 1186867188
      Quiet time after excitation: 1186867213

    • Quiet time before excitation: 1186869043
      Excitation broadband: 1186869078
      Quiet time after excitation: 1186869104

    • Quiet time before excitation: 1186870934
      Excitation broadband: 1186870969
      Quiet time after excitation: 1186870994

    • Quiet time before excitation: 1186872824
      Excitation broadband: 1186872859
      Quiet time after excitation: 1186872885

    • Quiet time before excitation: 1186874715
      Excitation broadband: 1186874750
      Quiet time after excitation: 1186874775

    • Quiet time before excitation: 1186876605
      Excitation broadband: 1186876640
      Quiet time after excitation: 1186876665

    • Quiet time before excitation: 1186878495
      Excitation broadband: 1186878530
      Quiet time after excitation: 1186878555

    • Quiet time before excitation: 1186880385
      Excitation broadband: 1186880420
      Quiet time after excitation: 1186880446

2017-08-16

  • 8:50am, valve close, pumps stopped, venting
  407   Tue Aug 15 00:09:01 2017 ZachElectronicsModelingESD Improvements

2017-08-14

  • I did my best to increase the excitation in the higher order modes. By making the ESD narrower (a 6mm electrode overlap) the higher order excitation is improved drastically, by factors of between 10 and 30 for most modes.  I also created a double ESD (see image) that excited the modes by a factor of 3 or more better than the thinner drive. The plotted ratios are relative to the original geometry, but both of these geometries do better than previous geometries by factors of 2 or 3. 
  • After a lot of experimentation, I think that there are non-trivial numerical artifacts from the force projection method. I have noticed that in the modes that are almost entirely unchanged by modifications, both the mode and its doublet have equal regions of positive and negative antinodes directly above the ESD force profile. This can be more clearly seen in the attached mode plot, the rectangle represents the region of the ESD. As a result of this, when the mode shape and force profile are multiplied and integrated the resultant force is very small. I expect this does not appear in the lab because the modes could be rotated at a different angle relative to the ESD. I am not sure how to effectively resolve this, perhaps checking other rotations of the mode shapes could be productive though I am unsure how to effectively accomplish this. 

Attachment 1: double.pdf
double.pdf
Attachment 2: double.jpg
double.jpg
Attachment 3: offset10.jpg
offset10.jpg
Attachment 5: offset10.jpg
offset10.jpg
Attachment 6: double.jpg
double.jpg
Attachment 9: thin.png
thin.png
  406   Fri Aug 11 09:22:21 2017 GabrieleMechanicsConfigurationESD moved closer to disk in CR0

The plots below compare the SNR and peak amplitude of all excited modes, in the new and old configuration. The new confgiuration is worse than the old one. This is unexpected, since the distance between ESD and disk is smaller.

However, yesterday we found out that setting the ESD so close to the disk is very tricky, and we might have some touching.

Additionally, the measured Q values of all modes are signfiicantly lower (by factors of >3), so it seems there is some additional friction. The mode frequencies are still compatible with the expected values, so it's unlikely that the ESD is touching the disk. One possible explanation for the worse Q can be residual gas damping in the area between the ESD and the disk: basically the gas moelcules that are left in the enclosed region between disk and ESD can create a viscous damping, which gets larger when the distance gets smaller [PhysRevLett.103.140601arxiv:0907.5375]. I'll try to do some computations later today.

 

Quote:

We first measured the distance of the ESD from the disk in the test chamber (CR0). We had to remove the retaining ring to have reliable measurements

  • distance between top of the ESD and mounting plate: 12.30 mm
  • distance between top of the disk and mounting plate: 10.53 mm
  • ESD thickness: 0.55 mm

So initially the distance between disk and ESD is 1.22 mm

We re-aligned the optical setup to a horizontal reference, and moved down the ESD as much as we could. It's not completely clear if the ESD is touching the disk. We'll see after pump down. The new distance from the top of the ESD to the mounting plate is about 11.80 mm, so we should have moved the ESD 0.5mm closer to the disk.

Pump down started at ~1:30pm

Excitations

  • Old configuration, 1.2mm distance ESD-disk:
    • GPS before exc. 1186417492 
    • GPS after exc. 1186417546
  • New configuration, 0.7mm distance ESD-disk
    • GPS before exc. 
    • GPS after exc.

 

  405   Thu Aug 10 13:36:08 2017 Gabriele, ZachMechanicsConfigurationESD moved closer to disk in CR0

We first measured the distance of the ESD from the disk in the test chamber (CR0). We had to remove the retaining ring to have reliable measurements

  • distance between top of the ESD and mounting plate: 12.30 mm
  • distance between top of the disk and mounting plate: 10.53 mm
  • ESD thickness: 0.55 mm

So initially the distance between disk and ESD is 1.22 mm

We re-aligned the optical setup to a horizontal reference, and moved down the ESD as much as we could. It's not completely clear if the ESD is touching the disk. We'll see after pump down. The new distance from the top of the ESD to the mounting plate is about 11.80 mm, so we should have moved the ESD 0.5mm closer to the disk.

Pump down started at ~1:30pm

Excitations

  • Old configuration, 1.2mm distance ESD-disk:
    • GPS before exc. 1186417492 
    • GPS after exc. 1186417546
  • New configuration, 0.7mm distance ESD-disk
    • GPS before exc. 
    • GPS after exc.
  404   Thu Aug 10 11:36:34 2017 GabrieleGeneralMeasurementsS1600541

2017-08-10

  • 11:25am, pumps stopped
Quote:

2017-06-28

We plan to leave S1600541 in vacuum for a long period, and measure the Q's periodically.

  • 3:48pm, S1600541 installed in CR0
  • 3:50pm, roughing pump on
  • 4:35pm turbo pump on

 

  403   Thu Aug 10 11:32:09 2017 GabrieleGeneralMeasurementsMode peak amplitudes with reference ESD

The uncoated, annealed and CO2 polished substrate S1600541 is installed in chamber CR0. This morning I performed a quick excitation: 1.6kV peak, broadband noise (500Hz - 32768 Hz), duration 20s. I measured the peak amplitude right after the excitation. The first plot below shows the SNR for all the detected 19 modes, as a function of frequency. The second plot shows the peak amplitude in physical units (radians/rHz of disk surface tilt) for all modes. The calibration of the surface motion should be reasonably good, better than a factor 2 of uncertaint. The attached TXT file contains the numerical data.

Attachment 3: peaks.txt
   1.1299461e+03   4.1911883e-06   3.7890494e+03
   2.5911635e+03   3.7687909e-06   2.9654534e+03
   4.5081875e+03   7.0826275e-07   3.4932225e+03
   6.8666454e+03   1.8347384e-06   3.7284735e+03
   6.8998265e+03   7.2550890e-08   1.4606621e+02
   9.6542682e+03   9.2541866e-07   4.2092492e+03
   1.0397923e+04   1.3057807e-07   7.8362131e+02
   1.2860601e+04   1.9470780e-07   1.4041656e+03
   1.4422018e+04   1.0362112e-07   6.3149271e+02
   1.6384301e+04   3.2555068e-08   2.0573770e+02
... 10 more lines ...
  402   Thu Aug 10 10:47:54 2017 ZachElectronicsModelingGeometry Ratios

2017-08-10

  • The attached plots compare the new and old geometries with .5 mm and 1 mm sample gaps. They are the same plot on linear and logarithmic axes respectively

 

 

Attachment 1: Optimization_plot_lin.pdf
Optimization_plot_lin.pdf
Attachment 2: Optimization_plot_log.pdf
Optimization_plot_log.pdf
  401   Wed Aug 9 17:07:57 2017 ZacharyElectronicsModelingOptimization Summary

2017-08-09

  • From the data I have gathered from a variety of MATLAB sweeps, I think that the optimal geometry I can produce has the parameters in the attached image. Neither the original or optimized drawing is to scale. The gap between the arms of the electrodes should be 1.25 mm, the arm width 0.55 mm, the arm length 16 mm, and the offset of the arms 3.5 mm.

  • It is also optimal to place the ESD as close to the sample disk as can reasonably be achieved, at around 0.5 mm away. Since the force on the disk scales exponentially with the distance from the ESD, decreasing that gap is the most substantial way to impact the excitation. Decreasing the gap from 1 mm to .5 mm increases the excitation of the modes by approximately a factor of 8.

  • From my simulations, the shift in geometry alone still has a useful impact on the excitation. Modes 1 and 3 are the only two modes that are less excited by the new geometry, mode 1 is 10% weaker  and mode 5 is 5% weaker. Modes 5 and 6 are nearly unaffected by the shift, mode 5 is 2% stronger and mode 6 is 5% stronger.  Modes 7, 18 and 19 are outliers, 7 is excited by a factor of 7, 18 by a factor of 4 and 19 by a factor of 17. The rest of the modes are improved by between a factor of 1.5 and 3. For mode numbers, shapes, and frequencies a plot is included.

Attachment 1: resonantmodes.pdf
resonantmodes.pdf
  400   Wed Aug 9 15:57:28 2017 ZachElectronicsModelingTriangular Geometry

2017-08-09

  • I compared the triangular geometry to the original geometry and the excitation was only improved in 7 of the of 20 modes. In four of those modes the improvement factors ranged from almost 2 to over 3 while the other modes where only improved by about 25%. The other 13 modes were diminished drastically, 9 of them where less than half as excited. Given more time it may have been interesting to try and optimize the geometry of a triangular drive, but that would easily take the better part of a week. 

  399   Wed Aug 9 12:10:47 2017 ZachElectronicsModelingPreliminary improvement from ESD optimization

2017-08-09

  • I created a plot of the ratio of the force in the optimized design to the force in the original design. The improvement factor is huge, some modes are excited by more than a factor of 100. I took the same ratio keeping the gap between the ESD and the sample constant and it decreased the excitation by almost a factor of 10. Keeping that gap constant, the geometric modifications to the ESD give an improvement factor ranging from almost 2 to almost 4 for most of the modes. Modes 10 and 25 are outliers but in the original geometry they are barely excited at all, so this could easily be a numerical artifact where those modes were excited at a minimum in the original geometry.

Attachment 1: Ratio.jpg
Ratio.jpg
  398   Tue Aug 8 16:20:24 2017 ZachElectronicsModelingRotated ESD

2017-08-08

  • I rotated the ESD and calculated it's modal projections by rotating the data array that MATLAB extracts from COMSOL. I confirmed that this was properly done by plotting the profile and then computed and plotted both the rotated and normal projections.
  • The rotated ESD actually increases the force in some of the modes but decreases the forces in others. It markedly improved the force in 7 of the modes: 3, 6, 12, 18, 19, 22, and 26 while being quite weaker in about 4 of the modes: 9, 13, 14, and 15. This suggests that it may actually be useful to rotate the ESD as it excites some of the higher order modes a noticeable amount more. I am including plots of both modal profiles as well as a chart with mode numbers, shapes, and frequencies.

 

Attachment 1: ESD.pdf
ESD.pdf
Attachment 2: Rotated.pdf
Rotated.pdf
Attachment 3: resonantmodes.pdf
resonantmodes.pdf
  397   Tue Aug 8 11:21:19 2017 GabrieleGeneralMeasurementsS1600557 S1600558 S1600559 S1600560

2017-08-08

  • 11:10am in chamber
    • S1600557 in CR1
    • S1600558 in CR2
    • S1600559 in CR3
    • S1600560 in CR4
  • 11:13am roughing pump on
  • 11:21am turbo pump on
  • Excitation:
    • Quiet time before excitation: 1186262071
      Excitation broadband: 1186262106
      Quiet time after excitation: 1186262131

    • Quiet time before excitation: 1186269362
      Excitation broadband: 1186269397
      Quiet time after excitation: 1186269422

    • Quiet time before excitation: 1186276652
      Excitation broadband: 1186276687
      Quiet time after excitation: 1186276712

    • Quiet time before excitation: 1186283942
      Excitation broadband: 1186283977
      Quiet time after excitation: 1186284002

    • Quiet time before excitation: 1186291232
      Excitation broadband: 1186291267
      Quiet time after excitation: 1186291292

    • Quiet time before excitation: 1186298522
      Excitation broadband: 1186298557
      Quiet time after excitation: 1186298582

2017-08-15

  • 10:04am, pumps off, valve closed, venting

 

  396   Tue Aug 8 10:18:30 2017 GabrieleGeneralMeasurementsEffect of assist beam on tantala coatings - after post deposition annealing

Introduction

The same set of samples described in the previous entry have been annealed at 500C for 9 hours. Then the loss angles have been measured again.

Results

The plot below shows the measured loss angle for all modes and all samples. After annealing all loss angles are significantly decreased, and they also show an increasing trend with frequency. As before, the blue points are the measurement points (averages of 8 ring-downs each) and the error bars are computed from the statistical error of the measurments. The red line shows the average of the loss angles for frequencies below 15 kHz, weigthed with the data points uncertainties. The red shaded area shows the 95% confidence interval of the mean.

If we plot the frequency-averaged loss angle as a function of the serial number, we see that there isn't much of a spread in the values:

We can again plot the loss angle as a function of the process variables. There are three main parameters that are changed in the deposition: the assist beam voltage, the assist beam current and the content of oxygen in the assist beam. The plots below show the losses as a function of those parameters. The x axis changes in each of the four panels, and for each plot, the color code is linked to one of the process variables:

This time I can't see much of a trend anywhere in those plots.

Linear fit

Since the loss angles show a clear increasing trend with frequency, instead of computing the mean value, I fit each dataset with a linear dependency on the frequency. To improve the fit I restricted the computations only to frequencies below 12 kHz. The results are shown below

The following plot shows the fitted loss angle at 1 kHz, as a function of the serial number. There is more spread in the results than when using the simple average:

 

And again, the dependency of the loss angle at 1 kHz on the process parameters:

The lowest loss angle is obtaine on sample S1600525, which was deposited without oxygen, low current and low voltage. But it's also the one sample that was deposited in a precedent separate run, and annealed twice at 500C.

 

  395   Tue Aug 8 09:58:34 2017 GabrieleGeneralMeasurementsEffect of assist beam on tantala coatings - no post deposition annealing

ntroduction

A set of substrates have been coated by the Colorado State University Fort Collins group, with ~500 nm tantala and various ion assist beam parameters. Here's a table summarizing the depositions parameter, by Le Yang

 

substrate

main ion source voltage / V

main ion source current / mA

main ion source Ar flow / sccm

target oxygen flow / sccm

assist ion source voltage / V

assist ion source current / mA

assist ion source gas/sccm

thickness / nm

abs

/ ppm

notes

Ar

O2

s1600525 1250 600 18 49 100 100 12.5 0 480    

s1600535

1250

600

18

49

100

100

12.5

0

541

7.2

 

s1600536

1250

600

18

49

100

100

3.5

9

532

20.2

 

s1600537

1250

600

18

49

100

100

6.5

6

534

 

damaged

by

holder

s1600538

1250

600

18

49

100

100

6.5

6

524

 

scratch

s1600547

1250

600

18

49

100

100

6.5

6

528

15.4

 

s1600532

1250

600

18

49

200

100

12.5

0

518

17.8

 

s1600539

1250

600

18

49

200

100

3.5

9

541

17.7

 

s1600533

1250

600

18

49

200

100

6.5

6

539

11.6

 

s1600530

1250

600

18

49

100

200

12.5

0

537

10.3

 

s1600550

1250

600

18

49

100

200

3.5

9

519

19.9

 

s1600548

1250

600

18

49

100

200

6.5

6

532

17.2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Coating losses before annealing

The plot below shows the measured loss angle for all modes of all samples, before annealing. The error bars for the datapoints are from the 95% confidence intervals computed from 8 measurements each. The red line is the average value over frequencies, and the shaded red area gives the 95% confidence interval of the mean value. The loss angle seems reasonably indipendent of frequency.

The following pot then shows the averaged loss angle as a function of the serial number, for reference

There are three main parameters that are changed in the deposition: the assist beam voltage, the assist beam current and the content of oxygen in the assist beam. The plots below show the losses as a function of those parameters. The x axis changes in each of the four panels, and for each plot, the color code is linked to one of the process variables:

Conclusions

Quoting Le Yang and Carmen Menoni

  1. under certain conditions as oxygen flow increase and Ar flow decrease, the loss angle becomes worse
  2. with existence of oxygen ions the loss is mitigated by increase of beam voltage
  3. relatively small particle size of oxygen compared with argon the caused the less effective interaction between assist ions and coating adatoms on the surface
  4. with increase of ion dose, the mechanical loss drops
  394   Mon Aug 7 13:19:48 2017 ZachElectronicsModelingNormalized data

2017-08-07

  • I included the modal mass factors in the code and renormalized my data. The normalization has a noticeable impact, but does not change the general trends of the data
  • In fact the impact is not even significant enough to warrant a change in the ideal parameters I picked for the rectangular ESD in my interim report

Attachment 1: Arm_gap.pdf
Arm_gap.pdf
Attachment 2: Arm_width.pdf
Arm_width.pdf
Attachment 3: Offset.pdf
Offset.pdf
Attachment 4: Sample_Gap.pdf
Sample_Gap.pdf
  393   Mon Aug 7 10:44:53 2017 GabrieleGeneralMeasurementsS1600525 S1600530 S1600532 S1600533

2017-08-07

  • 10:36am in chamber
    • S1600525 in CR1
    • S1600530 in CR2
    • S1600532 in CR3
    • S1600533 in CR4
  • 10:38am roughing pump on
  • 10:46am turbo pump on
  • Excitations
    • Quiet time before excitation: 1186171948
      Excitation broadband: 1186171983
      Quiet time after excitation: 1186172008

    • Quiet time before excitation: 1186173838
      Excitation broadband: 1186173873
      Quiet time after excitation: 1186173899

    • Quiet time before excitation: 1186175729
      Excitation broadband: 1186175764
      Quiet time after excitation: 1186175789

    • Quiet time before excitation: 1186177619
      Excitation broadband: 1186177654
      Quiet time after excitation: 1186177679

    • Quiet time before excitation: 1186179510
      Excitation broadband: 1186179545
      Quiet time after excitation: 1186179570

    • Quiet time before excitation: 1186181400
      Excitation broadband: 1186181435
      Quiet time after excitation: 1186181460

    • Quiet time before excitation: 1186183290
      Excitation broadband: 1186183325
      Quiet time after excitation: 1186183350

    • Quiet time before excitation: 1186185180
      Excitation broadband: 1186185215
      Quiet time after excitation: 1186185240

2017-08-08

  • 10:58am, valve closed, pumps stopped, venting
  392   Sat Aug 5 13:46:08 2017 GabrieleGeneralMeasurementsS1600539 S1600547 S1600548 S1600550

2017-08-05

  • 1:37pm in chamber
    • S1600539 in CR1
    • S1600547 in CR2
    • S1600548 in CR3
    • S1600550 in CR4
  • 1:39pm roughing pump on
  • 1:47pm turbo pump on
  • Excitations
    • Quiet time before excitation: 1186015242
      Excitation broadband: 1186015278
      Quiet time after excitation: 1186015303

    • Quiet time before excitation: 1186017133
      Excitation broadband: 1186017168
      Quiet time after excitation: 1186017193

    • Quiet time before excitation: 1186019023
      Excitation broadband: 1186019058
      Quiet time after excitation: 1186019083

    • Quiet time before excitation: 1186020913
      Excitation broadband: 1186020948
      Quiet time after excitation: 1186020973

    • Quiet time before excitation: 1186022803
      Excitation broadband: 1186022838
      Quiet time after excitation: 1186022863

    • Quiet time before excitation: 1186024694
      Excitation broadband: 1186024729
      Quiet time after excitation: 1186024754

    • Quiet time before excitation: 1186026584
      Excitation broadband: 1186026619
      Quiet time after excitation: 1186026644

    • Quiet time before excitation: 1186028474
      Excitation broadband: 1186028509
      Quiet time after excitation: 1186028534

2017-08-07

  • 10:23am, valve closed, pumps off, venting
  391   Fri Aug 4 14:15:16 2017 Gabriele, RosalieGeneralMeasurementsS1600535, S1600536, S1600537, S1600538

2017-08-04

  • 2:04pm in chamber
    • S1600535 in CR1
    • S1600536 in CR2
    • S1600537 in CR3
    • S1600538 in CR4
  • 2:06pm roughing pump on
  • 2:15pm turbo pump on
  • Excitations:
    • Quiet time before excitation: 1185930952
      Excitation broadband: 1185930987
      Quiet time after excitation: 1185931013

    • Quiet time before excitation: 1185932843
      Excitation broadband: 1185932878
      Quiet time after excitation: 1185932903

    • Quiet time before excitation: 1185934733
      Excitation broadband: 1185934768
      Quiet time after excitation: 1185934793

    • Quiet time before excitation: 1185936623
      Excitation broadband: 1185936658
      Quiet time after excitation: 1185936683

    • Quiet time before excitation: 1185938513
      Excitation broadband: 1185938548
      Quiet time after excitation: 1185938573

    • Quiet time before excitation: 1185940403
      Excitation broadband: 1185940438
      Quiet time after excitation: 1185940463

    • Quiet time before excitation: 1185942293
      Excitation broadband: 1185942328
      Quiet time after excitation: 1185942353

    • Quiet time before excitation: 1185944183
      Excitation broadband: 1185944218
      Quiet time after excitation: 1185944243

 

2017-08-05

  • 1:23pm valve closed, pumps stopped, venting

 

  390   Thu Aug 3 11:55:18 2017 Gabriele, RosalieGeneralMeasurementsS1600520 S1600521 S1600523 S1600524

2017-08-03

  • 11:43am in chamber
    • S1600520 in CR1
    • S1600521 in CR2
    • S1600523 in CR3
    • S1600524 in CR4
  • 11:46am roughing pump on
  • 11:55am turbo pump on
  • Excitations:
    • Quiet time before excitation: 1185835692
      Excitation broadband: 1185835727
      Quiet time after excitation: 1185835752

    • Quiet time before excitation: 1185837582
      Excitation broadband: 1185837617
      Quiet time after excitation: 1185837642

    • Quiet time before excitation: 1185839472
      Excitation broadband: 1185839507
      Quiet time after excitation: 1185839532

    • Quiet time before excitation: 1185841362
      Excitation broadband: 1185841397
      Quiet time after excitation: 1185841422

    • Quiet time before excitation: 1185843252
      Excitation broadband: 1185843287
      Quiet time after excitation: 1185843312

    • Quiet time before excitation: 1185845143
      Excitation broadband: 1185845178
      Quiet time after excitation: 1185845203

    • Quiet time before excitation: 1185847033
      Excitation broadband: 1185847068
      Quiet time after excitation: 1185847093

    • Quiet time before excitation: 1185848923
      Excitation broadband: 1185848958
      Quiet time after excitation: 1185848983

2017-08-04

  • 2:00pm valve closed, pumps off, venting
  389   Wed Aug 2 15:40:00 2017 ZachElectronicsModelingParameter diagram

I am posting a diagram of the geometric parameters that I swept. The only one not included is the vertical space between the ESD and sample that sweeps perpendicularly out of the image

 

  388   Wed Aug 2 13:47:47 2017 ZachElectronicsModelingArm width Sweep

2017-08-02

  • I ran a sweep of the width of the ESD arms. There appears to be a linear relationship across the modes except for mode 25. Mode 25 exhibits a very similar behavior as in the arm gap sweep. I realized that the abrupt change in direction (also noticeable in mode 14) is likely caused by the fact that the force profile is calculated as absolute value, there might be an exponential relationship that gets converted into that shape by the absolute value function. 

  387   Wed Aug 2 11:45:27 2017 Gabriele, RosalieGeneralMeasurementsS1600553, S1600554, S1600555, S1600556

2017-08-02

  • 11:33am in chamber
    • S1600553 in CR1
    • S1600554 in CR2
    • S1600555 in CR3
    • S1600556 in CR4
  • 11:35am roughing pump on
  • 11:45am turbo pump on
  • Excitations:
    • Quiet time before excitation: 1185760223
      Excitation broadband: 1185760258
      Quiet time after excitation: 1185760283

    • Quiet time before excitation: 1185767513
      Excitation broadband: 1185767548
      Quiet time after excitation: 1185767573

    • Quiet time before excitation: 1185774804
      Excitation broadband: 1185774839
      Quiet time after excitation: 1185774864

    • Quiet time before excitation: 1185782094
      Excitation broadband: 1185782129
      Quiet time after excitation: 1185782154

    • Quiet time before excitation: 1185789384
      Excitation broadband: 1185789419
      Quiet time after excitation: 1185789444

    • Quiet time before excitation: 1185796675
      Excitation broadband: 1185796710
      Quiet time after excitation: 1185796735

2017-08-03

  • 11:00am valve closed, pumps stopped, venting
  386   Tue Aug 1 16:10:42 2017 ZachElectronicsModelingImproved Gap Sweep

2017-08-01

  • I completed an improved sweep of the gap between the ESD arms. I resolved some code issues, since it was passing the maximum value not the most extreme, smaller magnitude positive values were being included rather than the strongest force calculation.
  • There are still three modes that show unique behavior relative to the others: 14, 19, and 25. Mode 14 is the (2,2), mode 19 is the (2,3) and mode 25 is (3,2).
  • Plots of the mode shapes are included for reference. The black rectangle represents the region covered by the ESD.

  385   Tue Aug 1 10:19:39 2017 Gabriele, RosalieGeneralMeasurementsS1600519, S1600522

2017-08-01

  • 10:05am, in chamber
    • S1600519 in CR1
    • S1600522 in CR2
  • 10:11am, roughing pump on
  • 10:19am, turbo pump on
  • Excitations
    • Quiet time before excitation: 1185649996
      Excitation broadband: 1185650031
      Quiet time after excitation: 1185650056

    • Quiet time before excitation: 1185651286
      Excitation broadband: 1185651321
      Quiet time after excitation: 1185651346

    • Quiet time before excitation: 1185652576
      Excitation broadband: 1185652611
      Quiet time after excitation: 1185652636

    • Quiet time before excitation: 1185653866
      Excitation broadband: 1185653901
      Quiet time after excitation: 1185653926

    • Quiet time before excitation: 1185655156
      Excitation broadband: 1185655191
      Quiet time after excitation: 1185655216

    • Quiet time before excitation: 1185656446
      Excitation broadband: 1185656481
      Quiet time after excitation: 1185656506

    • Quiet time before excitation: 1185657737
      Excitation broadband: 1185657772
      Quiet time after excitation: 1185657797

    • Quiet time before excitation: 1185659027
      Excitation broadband: 1185659062
      Quiet time after excitation: 1185659087

2017-08-02

  • 11:25am valve closed, venting, pumps off
  384   Mon Jul 31 13:21:37 2017 Gabriele, RosalieGeneralMeasurementsS1600520 S1600521 S1600523 S1600524

2017-07-31

  • 1:20pm in chamber
    • S1600520 in CR1
    • S1600521 in CR2
    • S1600523 in CR3
    • S1600524 in CR4
  • 1:21pm roughinp pump on
  • 1:30pm turbo pump on
  • Excitations:
    • Quiet time before excitation: 1185582780
      Excitation broadband: 1185582815
      Quiet time after excitation: 1185582840

    • Quiet time before excitation: 1185584070
      Excitation broadband: 1185584105
      Quiet time after excitation: 1185584130

    • Quiet time before excitation: 1185585360
      Excitation broadband: 1185585395
      Quiet time after excitation: 1185585420

    • Quiet time before excitation: 1185586650
      Excitation broadband: 1185586685
      Quiet time after excitation: 1185586710

    • Quiet time before excitation: 1185587940
      Excitation broadband: 1185587975
      Quiet time after excitation: 1185588000

    • Quiet time before excitation: 1185589230
      Excitation broadband: 1185589265
      Quiet time after excitation: 1185589290

    • Quiet time before excitation: 1185590520
      Excitation broadband: 1185590555
      Quiet time after excitation: 1185590581

    • Quiet time before excitation: 1185591811
      Excitation broadband: 1185591846
      Quiet time after excitation: 1185591871

2017-08-01

  • 9:55am, valve closed, venting, pumps off
  383   Thu Jul 27 16:56:03 2017 ZachElectronicsModelingOffset Sweep

2017-07-27

  • I ran a low resolution sweep of the offset in the arms of the ESD, the space between the end of the arm and base of the opposite combs. The trends are much more subtle and are not coherent across as many of the modes. The lower frequency modes decrease slightly, while the force in the higher frequency modes increase more drastically. This is an interesting parameter, I will definitely run another sweep once I have written code that accounts for the mode pairs. Assuming the apparent trends are physically accurate, this could be a useful parameter because a greater offset gives a greater relative increase to the higher order modes while still leaving a substantial force on the lower order modes that are excited more easily anyway.

Attachment 1: Offset.jpg
Offset.jpg
  382   Thu Jul 27 13:37:31 2017 ZachElectronicsModelingCorrected sample gap sweep

2017-07-27

  • I resolved a couple more data processing bugs and calculated a sweep of the ESD-Sample gap from a distance of .5 mm to 1.5 mm. The resulting data behaves far more like I would expect from a force generated by an electric field, it seems to drop off like distance squared. This is a very strong correlation with a good intuitive explanation, and would suggest that it is prudent to place the ESD as close to the sample as possible.
  • I also computed a higher resolution sweep of the gap between the arms of the ESD. It did not resolve the strange behavior at all, so I will investigate coupling into the mode pairs as a possible source.

Attachment 1: Fine_sample_gap.jpg
Fine_sample_gap.jpg
Attachment 3: fine_arm_gap.jpg
fine_arm_gap.jpg
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