ID 
Date 
Author 
Type 
Category 
Subject 
352

Thu Jun 22 15:37:20 2017 
Zach  Electronics  Modeling  Beginning modeling 
20170622
 Created the geometry of the ESD by creating blocks and joining them with Unions. I then created a block to serve as the domain and added air to that region
 This plot is a combination of a Surface plot of the potential and a Streamline plot of the electric field
 I created another model of the ESD with more accurate measurements to the real thing and added the silica disc to the model

353

Fri Jun 23 12:02:12 2017 
Zach  Electronics  Modeling  Plots 
20170623
 I created plots of the E field and potential from my rough model of the ESD. This model has 1mm electrode arm widths and spacings, the length of each arm is 16 mm, and the resulting total size is 38mm x 20 mm x 0.1 mm. One comb has ten arms while the other has nine to match the actual ESD currently in use in the lab.
 I set the ten arm comb to a potential of 100 V and the other to ground. I then used physics controlled mesh with an extremely fine element size to computer the simulations. With mesh sizes larger than extra fine, there was clearly nonphysical error in the electric field and potential graphs that appeared as inexplicable field lines, spikes, and coarseness in the plots.
 To create readable plots of the potential I created a Cut Plane in the center of the ESD perpendicular to both the arms and the plane of the device. The plots are attached with a milimeter length scale. I created a filled contour plot of the potential that is very clean, I tried a couple of different options for the electric field because it is harder to represent well. I created a contour plot for the norm of the electric field as well as superimposing a streamline plot of the field lines over that. Everything behaves generally as expected though I do suspect the spikes in electric field at the edges of each electrode are due to the fact that they are sharp corners and not smooth edges.

Attachment 1: Potential.png


Attachment 2: E_w_Lines.png


Attachment 3: Mesh.png


354

Sat Jun 24 12:59:27 2017 
Gabriele  General  Measurements  S1600541 S1600542 post annealing 
20170624
 12:47pm in chamber
 S1600541 in CR1
 S1600542 in CR3
 12:50pm roughing pump on
 12:59pm turbo pump on
 Excitations

Quiet time before excitation: 1182524202
Excitation broadband: 1182524237
Quiet time after excitation: 1182524262

Quiet time before excitation: 1182535092
Excitation broadband: 1182535127
Quiet time after excitation: 1182535152

Quiet time before excitation: 1182545982
Excitation broadband: 1182546017
Quiet time after excitation: 1182546042

Quiet time before excitation: 1182556872
Excitation broadband: 1182556907
Quiet time after excitation: 1182556932

Quiet time before excitation: 1182567762
Excitation broadband: 1182567797
Quiet time after excitation: 1182567822

Quiet time before excitation: 1182578652
Excitation broadband: 1182578687
Quiet time after excitation: 1182578712

Quiet time before excitation: 1182589542
Excitation broadband: 1182589577
Quiet time after excitation: 1182589602

Quiet time before excitation: 1182600432
Excitation broadband: 1182600467
Quiet time after excitation: 1182600492
20170628
 3:36pm, valve closed, vented, pumps stopped

355

Tue Jun 27 09:20:16 2017 
Alena  General  Annealing  Annealing run (546551) on 3" wafers  Crime 06/27/2017 
Started annealing run https://dcc.ligo.org/T1700293
Will be ready by June 28th afternoon 
356

Tue Jun 27 14:17:47 2017 
Zach  Electronics  Modeling  Further plots and improving models 
20170627
 I built a new model of the ESD to determine whether or not the spikes in the electric field at the corners was affecting the results enough that it had to be accounted for in further models. To create the model, I created a 2D profile of the arm used in my original model and filleted the corners at a radius of .05 mm, since the electrode model is .1 mm thick, this made completely rounded edges. In creating this model I caught an earlier mistake in the original one, I only set one half of the surface of the electrodes to have a potential or to ground, the "bottom" was left with no charge. I fixed this mistake and then compared the two models at a potential of 1000 V. For speed of computation I ran both models with a finer mesh size and then calculated the electric field at approximately the middle of the ESD, 1mm above the fourth electrode arm. For the rounded electrodes the field had a value of 84024 V/m and for the rectangular electrodes the field had a value of 80728 V/m, which is less than a 4% difference in field magnitude. Furthermore, the field shapes appear nearly indistinguishable; I am confident from this test that I can proceed modelling the arms of the ESD as rectangles.

Attachment 1: E_field_corner.png


Attachment 2: E_field_round.png


357

Wed Jun 28 15:50:15 2017 
Gabriele  General  Measurements  S1600541 
20170628
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

358

Thu Jun 29 13:15:01 2017 
Alastair, Gabriele  General  General  Laser polishing 
We laser polished S1600546, 547, 548, 549, 550 and 551 
359

Thu Jun 29 16:40:41 2017 
Zach  Electronics  Modeling  Accurate model and force profile 
20170629
 I created a much more accurate model of the current ESD setup from the technical drawings. My resulting ESD has dimensions of 21.3x24.3x.1mm with 1 mm spacings and 17.5 mm long electrode arms. The sample has a diameter of 75 mm and thickness of 1mm, the ESD is 1mm below the sample in the current model. I still have to compare the technical drawings to confirm that is the actual distance in the current lab setup.
 I was able to calculate the force profile on the disk from the ESD. COMSOL struggled to resolve the data with a small mesh size over the whole domain, so I created a region of extremely fine mesh around the ESD and the disk and then made the rest of the mesh size normal sized. Over the domain near the ESD my mesh size ranges from 2.5*10^{3} to .25 mm and over the rest of the domain it's automatically setup at the normal size.
 The force on a single dipole is given as , since fused silica is isotropic it's polarization is proportional to E so . The electric suscepitibility of fused silica is 1.09, I plotted the profile of the force perpendicular to the plane of the disk and exported data files of the full vector quantity of the force for use with Matlab.

360

Fri Jun 30 11:02:18 2017 
Zach  Electronics  Modeling  Matching Forces 
20170630
 I adjusted the plot parameters slightly so that it only showed the actual force profile on the sample in the direction perpendicular to the sample surface. Additionally I compared the two methods of computing the force, as and as . The profile of the force in both instances appear equal, but they differ in magnitude by exactly a factor of 2, I plotted the force computed with the explicit polarization doubled and the force magnitudes matched exactly. I'm still not entirely sure where this factor of two could be coming from.

361

Fri Jun 30 16:27:56 2017 
Zach  Electronics  Modeling  Double Checking Model 
20170630
 In order to confirm the accuracy of my model I checked some easily computable quantities between what real values and what COMSOL produced. My expected electric field magnitude between the electrodes is 10^{6} V/m and COMSOL reads out 1.015*10^{6 }which is less than a 2% error. When I went to compute the electric field gradient however, I discovered that I had been calculating my derivatives wrong, I was calculating full derivatives when I needed partial derivatives. Due to some subtleties of the numerics involving curl calculations are the order of the variables, in order to calculate a partial I belive that I have to map the results of the electric field to Lagrange elements.

362

Wed Jul 5 10:01:29 2017 
Gabriele  General  Measurements  S1600547 S1600548 S1600549 S1600550 
20170705
 NOTE: at 9:40am switched off turbo pump in CR0 to avoid vibrations
 NOTE: boxes are labeled as S1600546/547/548/549 but must be relabeled as S1600547/548/549/550
 9:53am, in chamber
 S1600547 in CR1
 S1600548 in CR2
 S1600549 in CR3
 S1600550 in CR4
 9:54am roughing pump on
 10:02am turbo pump on
 Excitations:

Quiet time before excitation: 1183323620
Excitation broadband: 1183323655
Quiet time after excitation: 1183323680

Quiet time before excitation: 1183330910
Excitation broadband: 1183330945
Quiet time after excitation: 1183330970

Quiet time before excitation: 1183338200
Excitation broadband: 1183338235
Quiet time after excitation: 1183338260

Quiet time before excitation: 1183345490
Excitation broadband: 1183345525
Quiet time after excitation: 1183345550

Quiet time before excitation: 1183352780
Excitation broadband: 1183352815
Quiet time after excitation: 1183352840

Quiet time before excitation: 1183360070
Excitation broadband: 1183360105
Quiet time after excitation: 1183360130

Quiet time before excitation: 1183367360
Excitation broadband: 1183367395
Quiet time after excitation: 1183367420

Quiet time before excitation: 1183374650
Excitation broadband: 1183374685
Quiet time after excitation: 1183374710
20170706
 3:45pm, valve closed, vented, pumps stopped

363

Wed Jul 5 12:01:51 2017 
Zach  Electronics  Modeling  Force plotsCorrect plots, force issue 
20170705
 I sorted out my mathematical lapse in logic and computed the correct force profiles in the perpendicular direction in both disks. The issue is that now the force profiles don't match up. The fact that there is a measured force distribution for the E^2 case outside the disk is only an artifact of the numerics because it is being calculated only from the electric field data which is defined outside the sample. It can be easily removed for final plots once the force distributions are matched by either redefining the cut plane or putting a data filter specifically on the E^2 plot. The jumps in the E^2 plot suggest that the meshing is still too large, I will try to fix this first, hopefully it will help resolve the difference.

364

Wed Jul 5 16:40:51 2017 
Zach  Electronics  Modeling  Force disparityimprovement 
20170705
 In order to improve my data I shrunk the region of the finer meshing slightly and made the mesh even smaller and then recalculated the force profiles. This time I tried sampling regions inside the disc rather than immediately at the surface. The attached graphs were sampled at the center of the disc. These two techniques vastly improved the data, now the profiles appear the same, but the magnitudes differ by a factor of 2 again. Previously this was due to an error in my calculation of the force, now I do not believe this to be the case. I will leave my work here for the purposes of my first report, it is an interesting result. I also restricted my data set to the finely meshed box which resolved the earlier data display issue.

365

Thu Jul 6 12:08:35 2017 
Zach  Electronics  Modeling  Checking physical parameters 
20170706
 I compared the electric field and the polarization to make sure that those calculations made sense. Since due to the linear dielectric, I plotted the electric field and the polarization divided by the proportionality constant and they match exactly.
 This confirms both the constant value and the polarization distribution but gets me no closer to resolving the factor of two

366

Thu Jul 6 12:48:54 2017 
Zach  Electronics  Modeling  Resolving the factor of two 
20170706
I resolved the factor of two from Griffiths' discussion of dipoles in nonuniform electric fields. The force on a dipole in a nonuniform field is where is the difference in the field between the plus end and the minus end. Component wise, where d is a unit vector. This holds for y and z, the whole thing can also be written as . Since p=qd, we can write .
Jackson derives it differently by deriving the electrostatic energy of a dielectric from the energy of a collection of charges in free space. He then derives the change in energy of a dielectric placed in a fixed source electric field to derive that the energy density w is given by . This explicity explains the factor of two and is an interesting alternative explanation. 
367

Wed Jul 12 15:08:59 2017 
Zach  Electronics  Modeling  Model of actuator and sample 
20170712
 I am attaching the first fully functioning model of the actuator and sample. I cleared both meshes and solutions to make the file a reasonable size, but they can quickly be built/solved again.

Attachment 1: Force_Model.mph

368

Fri Jul 14 16:43:24 2017 
Zach  Electronics  Modeling  Force profile matlab script 
20170714
 I have completed a rough, but functioning script that calculates the modal force profiles. The force values are still coming out incorrect (on the order of 10^14) but the script can take in my model as a .m file and return an array with a force value per mode. I am attaching both the .m file and the matlab script
 I have done very little work with the numerical integration itself, based on the 2D numerical integration code I received I just appended a z component and left it at that so when I return from Livingston I will fix that component

Attachment 1: forces.m

par.a = 75e3/2; % radius [m]
par.h = 1.004e3; % thickness [m]
par.E = 73.2e9; % Young's modulus [Pa]
par.nu = 0.155; % Poisson's ratio
par.rho = 2202; % density [kg/m^3]
%Calculate fundamental modes of the disk
[freqs, modes, shapes, x, y] = disk_frequencies(par, 10000, 1, 'shapes', 0.5e3);
%Now we extract the force profile from the COMSOL model
... 41 more lines ...

Attachment 2: faster.m

function out = model
%
% faster.m
%
% Model exported on Jul 14 2017, 14:47 by COMSOL 5.2.1.262.
import com.comsol.model.*
import com.comsol.model.util.*
model = ModelUtil.create('Model');
... 403 more lines ...

369

Tue Jul 18 09:13:08 2017 
Gabriele  General  Measurements  Shear and bulk losses in tantala 
S1600525 has been coated in Fort Collins with 480nm of pure tantala. I used the emasured loss angles (after deposition, before annealing) to estimate the shear and bulk loss angles.
Model
First, my COMSOL simulation shows that even if I don’t include the drumlike modes, I still have a significant scatter of shear/bulk energy ratio. The top panel shows indeed the ratio shear/bulk for all the modes I can measure, and the variation is quite large. So, contrary to my expectation, there is some room for fitting here. The bottom panel just shows the usual dilution factors.
Then I tried to fit the total losses in my sample (the substrate is negligible) using four different models:
1) one single loss angle for both bulk and shear, constant in frequency
2) one single loss angle for both bulk and shear, linear in frequency
3) separate bulk and shear loss angles, constant
4) separate bulk and shear loss angels, linear in frequency
Instead of using Gregg harry's technique (taking pairs of losses together), I simply fit the whole datasets with the assumptions above. I derived the 95% confidence intervals for all parameters. I also weighed each data point with the experimental uncertainty. I’m not sure yet how to compare the performance of the various models and decide which is the best one, since clearly the more parameters I plug into the model, the better the fit gets.
If I use two different loss angles, but constant, I get numbers similar to what Gregg presented at the last Amaldi conference ( G1701225), but inverted in bulk and shear. I cross checked that I didn’t do any mistake. Instead, if I allow linear dependency on frequency of bulk and shear, I get a trend similar to the one in Gregg's slides.
My plan is to have this sample annealed today or tomorrow and measure it again before the end of the week.
Results
One loss angle  constant
One loss angle  linear in frequency
Bulk and shear  constant
Bulk and shear  linear in frequency

370

Wed Jul 19 21:19:14 2017 
Gabriele  General  Measurements  Shear and bulk losses in tantala 
To quantify which of the fit below is the most significant, I did a Bayesian analysis (thanks Rory for the help!).
In brief, I compute the Bayes factors for each of the models considered below. As always in any Bayesian analysis, I had to assume some prior distribution for the fit parameters. I used uniform distributions, between 0 and 20e4 for the loss angles, and between 100e6 and 100e6 for the slope. I checked that the intervals I choose for the priors have only a small influence on the results.
The model that has the highest probability is the one that considers different bulk and shear frequency depent loss angles. The others have the following relative probabilities
One loss angle constant: 1/13e+13
One loss angle linear in frequency: 1/5.5
Bulk/shear angles constant: 1/48784
Bulk/shear angles linear in frequency: 1/1
So the constant loss angle models are excluded with large significance. The single frequency dependent loss angle is less probable that the bulk/shear frequency dependent model, but only by a factor of 5.5. According to the literature, this is considered a substantial evidence in favor of frequency dependent bulk/shear loss angles.
Quote: 
Results
One loss angle  constant
One loss angle  linear in frequency
Bulk and shear  constant
Bulk and shear  linear in frequency


371

Thu Jul 20 11:37:01 2017 
Zach  Electronics  Modeling  Matlab Script 
20170720
 I believe my MATLAB script successfully calculates the force distribution into each of the modes specified by the parameters. My previous error was caused by my neglecting the proportionality factor of . Now the force order of magnitude is on the order of 10^{3}. I am currently unclear how to think about the units of the mode shapes from the disk_frequencies script, but I will pick it apart more carefully and try to figure that out. Then it will be a matter of converting units so that it matches with the N/m^3 from the COMSOL script and then comparing with real lab results. It seems to me that the error in force distribution should be inversely proportional to the number of modes calculated, in which case it would be useful to determine an appropriate number of modes to calculate.

Attachment 1: forces.m

par.a = 75e3/2; % radius [m]
par.h = 1.004e3; % thickness [m]
par.E = 73.2e9; % Young's modulus [Pa]
par.nu = 0.155; % Poisson's ratio
par.rho = 2202; % density [kg/m^3]
%Calculate fundamental modes of the disk
[freqs, modes, shapes, x, y] = disk_frequencies(par, 10000, 1, 'shapes', 0.5e3);
%Now we extract the force profile from the COMSOL model
... 27 more lines ...

372

Fri Jul 21 08:42:09 2017 
Gabriele  General  Measurements  S1600525 
20170721
 8:30am, in chamber (CR4)
 8:32am, roughing pump on
 8:41am, turbo pump on
 Excitations

Quiet time before excitation: 1184697303
Excitation broadband: 1184697338
Quiet time after excitation: 1184697363

Quiet time before excitation: 1184698593
Excitation broadband: 1184698628
Quiet time after excitation: 1184698653

Quiet time before excitation: 1184699883
Excitation broadband: 1184699918
Quiet time after excitation: 1184699943

Quiet time before excitation: 1184701173
Excitation broadband: 1184701208
Quiet time after excitation: 1184701233

Quiet time before excitation: 1184702463
Excitation broadband: 1184702499
Quiet time after excitation: 1184702524

Quiet time before excitation: 1184703754
Excitation broadband: 1184703789
Quiet time after excitation: 1184703814

Quiet time before excitation: 1184705044
Excitation broadband: 1184705079
Quiet time after excitation: 1184705104

Quiet time before excitation: 1184706334
Excitation broadband: 1184706369
Quiet time after excitation: 1184706394
20170722
 12:13pm, valve closed, pumps off

373

Fri Jul 21 14:55:02 2017 
Gabriele  General  Measurements  Shear and bulk losses in annealed tantala 
I repeated the analysis for bulk and shear losses described in an early elog entry, with the same coating, but after annealing at 500C for 9 hours.
The COMSOL model is the same as before, so the dilution factors are the same, except that this time I could measure a few more modes at high frequency:
As in the previous analysis, I fitted four different models:
1) one single loss angle for both bulk and shear, constant in frequency
2) one single loss angle for both bulk and shear, linear in frequency
3) separate bulk and shear loss angles, constant
4) separate bulk and shear loss angles, linear in frequency
The data strongly favor the last model: two loss angles for shear and bulk, linearly dependent on frequency (Bayes factor 22.7 for the second best model, which is the frequency dependent single loss angle).
The results are below.
Single constant loss angle
Single loss angle, linearly dependent on frequency
Bulk and shear loss angles, constant
Bulk and shear loss angles, linearly dependent on frequency

Attachment 7: postannealing_linear_bulk_shear.png


374

Sat Jul 22 13:05:46 2017 
Gabriele  General  Measurements  S1600533 S1600535 S1600536 S1600547 
20170722
 12:55pm in chamber
 S1600533 in CR1
 S1600535 in CR2
 S1600536 in CR3
 S1600547 in CR4
 Added neutral densities
 12:57pm roughing pump on
 1:05pm turbo pump on
 Excitations

Quiet time before excitation: 1184803575
Excitation broadband: 1184803611
Quiet time after excitation: 1184803636

Quiet time before excitation: 1184804866
Excitation broadband: 1184804901
Quiet time after excitation: 1184804926

Quiet time before excitation: 1184806156
Excitation broadband: 1184806191
Quiet time after excitation: 1184806216

Quiet time before excitation: 1184807446
Excitation broadband: 1184807481
Quiet time after excitation: 1184807506

Quiet time before excitation: 1184808736
Excitation broadband: 1184808771
Quiet time after excitation: 1184808796

Quiet time before excitation: 1184810027
Excitation broadband: 1184810062
Quiet time after excitation: 1184810087

Quiet time before excitation: 1184811317
Excitation broadband: 1184811352
Quiet time after excitation: 1184811377

Quiet time before excitation: 1184812607
Excitation broadband: 1184812642
Quiet time after excitation: 1184812667

More excitations

Quiet time before excitation: 1184878758
Excitation broadband: 1184878794
Quiet time after excitation: 1184878819

Quiet time before excitation: 1184880049
Excitation broadband: 1184880084
Quiet time after excitation: 1184880109

Quiet time before excitation: 1184881339
Excitation broadband: 1184881374
Quiet time after excitation: 1184881399

Quiet time before excitation: 1184882629
Excitation broadband: 1184882664
Quiet time after excitation: 1184882689

Quiet time before excitation: 1184883919
Excitation broadband: 1184883954
Quiet time after excitation: 1184883979

Quiet time before excitation: 1184885210
Excitation broadband: 1184885245
Quiet time after excitation: 1184885270

Quiet time before excitation: 1184886500
Excitation broadband: 1184886536
Quiet time after excitation: 1184886561

Quiet time before excitation: 1184887791
Excitation broadband: 1184887826
Quiet time after excitation: 1184887851
20170724
 3:28pm valve closed, venting

375

Mon Jul 24 09:13:45 2017 
Zach  Electronics  Modeling  Parametric Sweep 
20170724
 I wrote a MATLAB script that is capable of sweeping parameters, the code is attached. The next step is to create nested loops so that I can sweep multiple parameters in a single run. I also should add a function in the script to eliminate the modes that cannot be measured by the experimental setup.
 My first sweep was for the gap between electrodes and swept from 1 to 2 mm. In the plot the gap grows from steps 1 to 6 and the only obvious effect in the plot is a decrease in force from the highest mode. Intuitively it makes sense that a wider gap would decrease the force because the electric field is diminished by spreading out the electrodes.
 I would like to add a parameter for the overlap of the electrodes, but this would require substantial redesigning of the COMSOL model due to the multilevel dependency on parameters.

Attachment 2: forcesweep.m

fpro = zeros(6, 27);
no = 1;
for count = 1:.2:2
gap = strcat(num2str(count), ' [mm]')
model = fst2(gap);
forces;
fpro(no, :)= product(:);
no = no + 1;
end

376

Mon Jul 24 16:06:11 2017 
Gabriele  General  Measurements  S1600530 S1600532 S1600537 S1600539 
20170724
 3:55pm installed in chamber
 S1600530 in CR1
 S1600532 in CR2
 S1600537 in CR3
 S1600539 in CR4
 3:58pm roughing pump on
 4:06pm turbo pump on
 Excitations:

Quiet time before excitation: 1184986754
Excitation broadband: 1184986789
Quiet time after excitation: 1184986814

Quiet time before excitation: 1184988044
Excitation broadband: 1184988079
Quiet time after excitation: 1184988104

Quiet time before excitation: 1184989334
Excitation broadband: 1184989369
Quiet time after excitation: 1184989394

Quiet time before excitation: 1184990625
Excitation broadband: 1184990660
Quiet time after excitation: 1184990685

Quiet time before excitation: 1184991915
Excitation broadband: 1184991950
Quiet time after excitation: 1184991975

Quiet time before excitation: 1184993205
Excitation broadband: 1184993240
Quiet time after excitation: 1184993265

Quiet time before excitation: 1184994495
Excitation broadband: 1184994530
Quiet time after excitation: 1184994555

Quiet time before excitation: 1184995785
Excitation broadband: 1184995820
Quiet time after excitation: 1184995845
20170725
 11:00am valve closed, pumps stopped, venting

377

Tue Jul 25 11:22:37 2017 
Gabriele  General  Measurements  S1600548 S1600550 S1600538 
20170725
 11:12am in chamber (non standard order is not a typo!!)
 S1600548 in CR1
 S1600550 in CR2
 S1600538 in CR3
 11:13am roughing pump on
 11:22am turbo pump on
 Excitations:

Quiet time before excitation: 1185056320
Excitation broadband: 1185056355
Quiet time after excitation: 1185056380

Quiet time before excitation: 1185057610
Excitation broadband: 1185057645
Quiet time after excitation: 1185057670

Quiet time before excitation: 1185058900
Excitation broadband: 1185058935
Quiet time after excitation: 1185058960

Quiet time before excitation: 1185060190
Excitation broadband: 1185060226
Quiet time after excitation: 1185060251

Quiet time before excitation: 1185061481
Excitation broadband: 1185061516
Quiet time after excitation: 1185061541

Quiet time before excitation: 1185062771
Excitation broadband: 1185062806
Quiet time after excitation: 1185062831

Quiet time before excitation: 1185064061
Excitation broadband: 1185064096
Quiet time after excitation: 1185064121

Quiet time before excitation: 1185065351
Excitation broadband: 1185065386
Quiet time after excitation: 1185065411
20170726
 4:05pm valve closed, pumps stopped, venting

378

Tue Jul 25 13:38:30 2017 
Zach  Electronics  Modeling  Parametric Sweep of ESD gap 
20170725
 I completed a short sweep of the gap between the drive and the sample, between .5 and 1 mm in .1 mm increments. It appears that a 1 mm distance is the ideal distance by approximately a factor of two. I will next sweep larger distances and see how the force profile behaves at greater distances.

379

Wed Jul 26 09:27:40 2017 
Zach  Electronics  Modeling  Sweeping the space between ESD and sample 
20170726
 I ran a sweep of the gap between the ESD and the sample, first from .5 mm to 1 mm. That sweep suggested that there is a significant jump in force across almost all of the modes at 1 mm. To confirm this I double checked the geometry and it appears that COMSOL is building everything as expected when changing the spacing parameter. Then I ran a finer sweep in .02 mm increments for the spacing between .9 and 1.1 mm. Once again it appears there is a large jump as the gap approaches 1 mm, but the behavior does not seem to be symmetric about that point, the force appears to diminish linearly as the gap increases beyond 1 mm. I will run a sweep of the ESD arm spacing along with the vertical gap to confirm that the jump occurs when the gap between the ESD and the sample is equivalent to the spacings between the ESD arms.

Attachment 1: Gap_near_one.jpg


380

Wed Jul 26 16:22:22 2017 
Gabriele  General  Measurements  S1600528 S1600531 
20170726
 4:14pm in chamber
 S1600528 in CR1
 S1600531 in CR2
 4:16pm roughing pump on
 4:23pm turbo pump on
 Excitations

Quiet time before excitation: 1185160841
Excitation broadband: 1185160876
Quiet time after excitation: 1185160901

Quiet time before excitation: 1185168131
Excitation broadband: 1185168167
Quiet time after excitation: 1185168192

Quiet time before excitation: 1185175422
Excitation broadband: 1185175457
Quiet time after excitation: 1185175482

Quiet time before excitation: 1185182712
Excitation broadband: 1185182747
Quiet time after excitation: 1185182772

Quiet time before excitation: 1185190002
Excitation broadband: 1185190038
Quiet time after excitation: 1185190063

Quiet time before excitation: 1185197293
Excitation broadband: 1185197329
Quiet time after excitation: 1185197354
20170727
 4:30pm, valve closed, pumps stopped, vented

381

Wed Jul 26 21:22:50 2017 
Zach  Electronics  Modeling  Parametric Sweep Results 
20170726
 I resolved the major bugs in the parametric sweep scripts and ran low resolution sweeps of the gap between the ESD and sample (Gap Sweep) and the spacing between the ESD arms (ESD Arm Gap Sweep).
 The arm gap sweep largely behaved in a reasonable way with a maximum excitation at a 1.25 mm gap. However modes 14, 19, and 25 did not follow the general trends and had sharp drops and increases compared to the other modes.
 The sample gap sweep had less intuitive behavior, all of the modes followed the same general double peak trend that drops to zero when the gap is 1.5 mm. I cannot explain exactly why it is behaving that way, I will run a higher resolution sweep and examine the geometry in greater detail.

382

Thu Jul 27 13:37:31 2017 
Zach  Electronics  Modeling  Corrected sample gap sweep 
20170727
 I resolved a couple more data processing bugs and calculated a sweep of the ESDSample 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


Attachment 3: fine_arm_gap.jpg


383

Thu Jul 27 16:56:03 2017 
Zach  Electronics  Modeling  Offset Sweep 
20170727
 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


384

Mon Jul 31 13:21:37 2017 
Gabriele, Rosalie  General  Measurements  S1600520 S1600521 S1600523 S1600524 
20170731
 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
20170801
 9:55am, valve closed, venting, pumps off

385

Tue Aug 1 10:19:39 2017 
Gabriele, Rosalie  General  Measurements  S1600519, S1600522 
20170801
 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
20170802
 11:25am valve closed, venting, pumps off

386

Tue Aug 1 16:10:42 2017 
Zach  Electronics  Modeling  Improved Gap Sweep 
20170801
 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.

387

Wed Aug 2 11:45:27 2017 
Gabriele, Rosalie  General  Measurements  S1600553, S1600554, S1600555, S1600556 
20170802
 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
20170803
 11:00am valve closed, pumps stopped, venting

388

Wed Aug 2 13:47:47 2017 
Zach  Electronics  Modeling  Arm width Sweep 
20170802
 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.

389

Wed Aug 2 15:40:00 2017 
Zach  Electronics  Modeling  Parameter 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

390

Thu Aug 3 11:55:18 2017 
Gabriele, Rosalie  General  Measurements  S1600520 S1600521 S1600523 S1600524 
20170803
 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
20170804
 2:00pm valve closed, pumps off, venting

391

Fri Aug 4 14:15:16 2017 
Gabriele, Rosalie  General  Measurements  S1600535, S1600536, S1600537, S1600538 
20170804
 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
20170805
 1:23pm valve closed, pumps stopped, venting

392

Sat Aug 5 13:46:08 2017 
Gabriele  General  Measurements  S1600539 S1600547 S1600548 S1600550 
20170805
 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
20170807
 10:23am, valve closed, pumps off, venting

393

Mon Aug 7 10:44:53 2017 
Gabriele  General  Measurements  S1600525 S1600530 S1600532 S1600533 
20170807
 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
20170808
 10:58am, valve closed, pumps stopped, venting

394

Mon Aug 7 13:19:48 2017 
Zach  Electronics  Modeling  Normalized data 
20170807
 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


Attachment 2: Arm_width.pdf


Attachment 3: Offset.pdf


Attachment 4: Sample_Gap.pdf


395

Tue Aug 8 09:58:34 2017 
Gabriele  General  Measurements  Effect 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

O_{2}

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
 under certain conditions as oxygen flow increase and Ar flow decrease, the loss angle becomes worse
 with existence of oxygen ions the loss is mitigated by increase of beam voltage
 relatively small particle size of oxygen compared with argon the caused the less effective interaction between assist ions and coating adatoms on the surface
 with increase of ion dose, the mechanical loss drops

396

Tue Aug 8 10:18:30 2017 
Gabriele  General  Measurements  Effect 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 ringdowns 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 frequencyaveraged 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.

397

Tue Aug 8 11:21:19 2017 
Gabriele  General  Measurements  S1600557 S1600558 S1600559 S1600560 
20170808
 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
20170815
 10:04am, pumps off, valve closed, venting

398

Tue Aug 8 16:20:24 2017 
Zach  Electronics  Modeling  Rotated ESD 
20170808
 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


Attachment 2: Rotated.pdf


Attachment 3: resonantmodes.pdf


399

Wed Aug 9 12:10:47 2017 
Zach  Electronics  Modeling  Preliminary improvement from ESD optimization 
20170809
 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


400

Wed Aug 9 15:57:28 2017 
Zach  Electronics  Modeling  Triangular Geometry 
20170809
 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.

401

Wed Aug 9 17:07:57 2017 
Zachary  Electronics  Modeling  Optimization Summary 
20170809

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

