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  Coating Ring-down Measurement Lab elog, Page 1 of 18  Not logged in ELOG logo
ID Date Author Type Categorydown Subject Text Attachments
  128   Tue Sep 27 08:53:46 2016 GabrieleGeneralVacuumEtched disk installedInstalled the etched disk: using manually
the centering ring allowed me to get the
beam on the QPD. A couple of taps to the
  
  133   Mon Oct 17 10:50:50 2016 GabrieleGeneralVacuumNo sign of problems in the electrostatic driveI opened the chamber and took the etched
disk out. Inspection of the electrostatic
drive does not show any sign of burn or damage.
  
  142   Fri Oct 21 14:03:17 2016 GabrieleGeneralVacuumRoughing pump movedI moved the roughing pump out of the clean
room, adding an extension hose.

 
 compare_pump.pngimprovement_pump.png 
  165   Mon Nov 7 11:27:16 2016 GabrieleGeneralVacuumTurbo pump excites some resonance at 58 HzI looked into a couple of turbo pump switch
on periods, and in both cases when the pump
speed hits 58 Hz, a resonance is excited.
  
  186   Mon Nov 14 11:28:33 2016 GabrieleGeneralVacuumViton padsI added three 1"x1" viton pads
below the base plate, and realigned the entire
optical system to the horizontal reference
 2016-11-14_10.41.47.jpg2016-11-14_10.41.57.jpgviton.png 
  195   Thu Nov 17 12:06:39 2016 GabrieleGeneralVacuumSwitching on the IGM moves the diskHere's a trend of the QPD signals when
the IGM was turned on:

 igm_on.png 
  264   Thu Jan 19 07:32:33 2017 AlenaGeneralVacuumNew chamber first pimp downThe new chamber was build. The first attempt
to pump down was unsuccessful because of
dislocated lid. After the lit was placed
 unnamed.jpg 
  265   Thu Jan 19 12:49:17 2017 GabrieleFacilityVacuumSkyhook installedThe SkyHook has been put in place and bolted
down to the floor.

 IMG_4241.JPGIMG_4241.JPGIMG_4241.JPGIMG_4241.JPG 
  267   Thu Jan 19 14:27:02 2017 AlenaGeneralVacuumFirst vacuum test new chamberTurbo pump controller (new chamber) was
configured. Need to reduce the frequency
or setup a standby mode. First pump down:
 20170119.png 
  285   Tue Jan 31 16:50:55 2017 Gabriele, AlenaGeneralVacuumFirst pump-down with setupThis afternoon we started the pump-down
with all the system installed into the chamber.
Unfortunately the IGM vacuum gauge isn't
  
  498   Tue Mar 27 16:37:22 2018 GabrieleGeneralVacuumTurbo pump for test chamber CR0 set pointI changed the set point of the test chamber
turbo pump to 666 Hz. This was done
by setting the "standby rotation speed"
  
  517   Thu Apr 12 10:33:06 2018 GabrieleGeneralVacuumRead-out of vacuum gaugesI failed to interface in a reliable way
the datalogger with Linux. So i hooked up
the four analog outputs of the vacuum gauge
 gauges.pngpressures.png 
  703   Tue May 28 15:48:42 2019 AlenaGeneralVacuumLow pressure gauge exchangeAfter venting the vacum chamber (CR14)
a few times, checking for leaks and trying
to tune settings to the gauges controller,
  
  170   Wed Nov 9 15:32:11 2016 GabrieleGeneralNoise huntingNoise below 2 kHz is not due to the roughing pump, but to the clean air filtersThe two spectra below show basically no
difference (blue roughing pump on, red, roughing
pump off)
 Screenshot-1.pngScreenshot.png 
  176   Thu Nov 10 17:04:05 2016 GabrieleGeneralNoise huntingTemporary second QPDThis morning I installed temporarily a
second QPD to monitor the input beam. The
goal was to understand where the vibrations
 2016-11-10_10.56.06.jpgspectra.pngcoherence_x.png 
  181   Sun Nov 13 10:11:19 2016 GabrieleGeneralNoise huntingNoise due to airThe plot below compares the QPD signal
spectra in different configurations (roughing
pump on/off, air on/off).
 air_noise.pngair_zoom.png 
  209   Wed Nov 23 08:55:41 2016 GabrieleGeneralNoise hunting"Advanced" vibration isolationIn normal conditions the RMS of the QPD
signals is dominated by the 58 Hz line generated
by the roughing pump. Also, when the modes
 2016-11-22_15.22.13.jpgvibration_isolation.png 
  216   Tue Nov 29 17:02:06 2016 GabrieleFacilityNoise huntingSuspending the roughing pumpI suspended the roughing pump with four
springs. The reduction of the 58 Hz peak
is similar to what I got when the pump was
 2016-11-29_11.08.17.jpg2016-11-29_11.12.35.jpg2016-11-29_11.08.21.jpg 
  287   Wed Feb 1 15:23:42 2017 GabrieleOpticsNoise huntingWandering line is due to the laserThe wandering line I mentioned in my previous
elog, which is spoiling most of the sensitivity,
turns out to be power noise of the laser. 
 laser_noise_rin.pngUntitled.avi 
  326   Thu Mar 2 11:27:47 2017 GabrieleGeneralNoise huntingTurbo pump of CR0 pollutes CR1The turbo pump of the CR0 chamber runs
at 833 Hz. It causes vibrations that pollute
the measurements in the CR1-4 chamber. In
 Screenshot.png 
  351   Thu Jun 22 13:16:37 2017 ZachElectronicsModelingBeginning with COMSOL2017-06-21


4:30 pm-
Installed COMSOL, began modeling current
ESD by creating parameters and the first
  
  352   Thu Jun 22 15:37:20 2017 ZachElectronicsModelingBeginning modeling2017-06-22


Created
the geometry of the ESD by creating blocks
and joining them with Unions. I then created
 E_Plot.png 
  353   Fri Jun 23 12:02:12 2017 ZachElectronicsModelingPlots2017-06-23


I created
plots of the E field and potential from my
rough model of the ESD. This model has 1mm
 Potential.pngE_w_Lines.pngMesh.png 
  356   Tue Jun 27 14:17:47 2017 ZachElectronicsModelingFurther plots and improving models2017-06-27


I built
a new model of the ESD to determine whether
or not the spikes in the electric field at
 E_field_corner.pngE_field_round.png 
  359   Thu Jun 29 16:40:41 2017 ZachElectronicsModelingAccurate model and force profile2017-06-29


I created
a much more accurate model of the current
ESD setup from the technical drawings. My
 Force.pnggeometry.pngMesh.png 
  360   Fri Jun 30 11:02:18 2017 ZachElectronicsModelingMatching Forces2017-06-30


I adjusted
the plot parameters slightly so that it only
showed the actual force profile on the sample
 ForceE.pngForceP.png 
  361   Fri Jun 30 16:27:56 2017 ZachElectronicsModelingDouble Checking Model2017-06-30


In order
to confirm the accuracy of my model I checked
some easily computable quantities between
  
  363   Wed Jul 5 12:01:51 2017 ZachElectronicsModelingForce plots-Correct plots, force issue2017-07-05


I sorted
out my mathematical lapse in logic and computed
the correct force profiles in the perpendicular
 Force_E2.pngForce_PE.png 
  364   Wed Jul 5 16:40:51 2017 ZachElectronicsModelingForce disparity-improvement2017-07-05


In order
to improve my data I shrunk the region of
the finer meshing slightly and made the mesh
 1ForceE2.png1ForcePE.png 
  365   Thu Jul 6 12:08:35 2017 ZachElectronicsModelingChecking physical parameters2017-07-06


I compared
the electric field and the polarization to
make sure that those calculations made sense.
 E_from_P.pngE_from_E.png 
  366   Thu Jul 6 12:48:54 2017 ZachElectronicsModelingResolving the factor of two2017-07-06

I resolved the factor
of two from Griffiths' discussion of
dipoles in non-uniform electric fields. The
  
  367   Wed Jul 12 15:08:59 2017 ZachElectronicsModelingModel of actuator and sample2017-07-12


I am attaching
the first fully functioning model of the
actuator and sample. I cleared both meshes
 Force_Model.mph 
  368   Fri Jul 14 16:43:24 2017 ZachElectronicsModelingForce profile matlab script2017-07-14


I have completed
a rough, but functioning script that calculates
the modal force profiles. The force values
 forces.mfaster.m 
  371   Thu Jul 20 11:37:01 2017 ZachElectronicsModelingMatlab Script2017-07-20


I believe
my MATLAB script successfully calculates
the force distribution into each of the modes
 forces.m 
  375   Mon Jul 24 09:13:45 2017 ZachElectronicsModelingParametric Sweep2017-07-24


I wrote
a MATLAB script that is capable of sweeping
parameters, the code is attached. The next
 gap_plot.jpgforcesweep.m 
  378   Tue Jul 25 13:38:30 2017 ZachElectronicsModelingParametric Sweep of ESD gap2017-07-25


I completed
a short sweep of the gap between the drive
and the sample, between .5 and 1 mm in .1
 modeplotESDgap.jpg 
  379   Wed Jul 26 09:27:40 2017 ZachElectronicsModelingSweeping the space between ESD and sample2017-07-26


I ran a
sweep of the gap between the ESD and the
sample, first from .5 mm to 1 mm. That sweep
 Gap_near_one.jpggap_sweep.jpgGap_near_one.jpg 
  381   Wed Jul 26 21:22:50 2017 ZachElectronicsModelingParametric Sweep Results2017-07-26


I resolved
the major bugs in the parametric sweep scripts
and ran low resolution sweeps of the gap
 ESD.armgap.jpgESD.sample.gap.jpg 
  382   Thu Jul 27 13:37:31 2017 ZachElectronicsModelingCorrected sample gap sweep2017-07-27


I resolved
a couple more data processing bugs and calculated
a sweep of the ESD-Sample gap from a distance
 Fine_sample_gap.jpgFine_sample_gap.jpgfine_arm_gap.jpgfine_arm_gap.jpg 
  383   Thu Jul 27 16:56:03 2017 ZachElectronicsModelingOffset Sweep2017-07-27


I ran a
low resolution sweep of the offset in the
arms of the ESD, the space between the end
 Offset.jpgOffset.jpg 
  386   Tue Aug 1 16:10:42 2017 ZachElectronicsModelingImproved Gap Sweep2017-08-01


I completed
an improved sweep of the gap between the
ESD arms. I resolved some code issues, since
 Better.jpgmode_14.jpgmode_19.jpgmode_25.jpg 
  388   Wed Aug 2 13:47:47 2017 ZachElectronicsModelingArm width Sweep2017-08-02


I ran a
sweep of the width of the ESD arms. There
appears to be a linear relationship across
 Arm_width_fine.jpgmode_25.jpg 
  389   Wed Aug 2 15:40:00 2017 ZachElectronicsModelingParameter diagramI am posting a diagram of the geometric
parameters that I swept. The only one not
included is the vertical space between the
 ESD_w_param.png 
  394   Mon Aug 7 13:19:48 2017 ZachElectronicsModelingNormalized data2017-08-07


I included
the modal mass factors in the code and renormalized
my data. The normalization has a noticeable
 Arm_gap.pdfArm_width.pdfOffset.pdfSample_Gap.pdf 
  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
 ESD.pdfRotated.pdfresonantmodes.pdf 
  399   Wed Aug 9 12:10:47 2017 ZachElectronicsModelingPreliminary improvement from ESD optimization2017-08-09


I created
a plot of the ratio of the force in the optimized
design to the force in the original design.
 Ratio.jpgRatio.jpgo_gap.jpgOriginal.jpgOptimized.jpg 
  400   Wed Aug 9 15:57:28 2017 ZachElectronicsModelingTriangular Geometry2017-08-09


I compared
the triangular geometry to the original geometry
and the excitation was only improved
 tratio.jpg 
  401   Wed Aug 9 17:07:57 2017 ZacharyElectronicsModelingOptimization Summary2017-08-09



p.p1 {margin: 0.0px 0.0px
0.0px 0.0px; font: 11.0px 'Helvetica Neue';
 6x 
  402   Thu Aug 10 10:47:54 2017 ZachElectronicsModelingGeometry Ratios2017-08-10


The attached
plots compare the new and old geometries
with .5 mm and 1 mm sample gaps. They are
 Optimization_plot_lin.pdfOptimization_plot_log.pdf 
  407   Tue Aug 15 00:09:01 2017 ZachElectronicsModelingESD Improvements2017-08-14


I did my
best to increase the excitation in the higher
order modes. By making the ESD narrower (a
 10x 
ELOG V3.1.3-