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ID Date Author Type Category Subjectup Text Attachments
  289   Wed Feb 1 16:58:10 2017 GabrieleGeneralCharacterizationExcitation testsThe excitation is working fine. However,
there is a large cross coupling in the excitation
between channels: so if I switch on only
  422   Thu Aug 24 07:40:33 2017 GabrieleGeneralMeasurementsExcitations with new ESD2017-08-23


time before excitation: 1187577794
Excitation broadband: 1187577826
  424   Fri Aug 25 07:25:32 2017 GabrieleGeneralMeasurementsExcitations with new ESDThe results show very low Q values, so
we suspected some issues. Yesterday we openend
the chamber and moved the ESD up, as high
  425   Fri Aug 25 19:29:07 2017 GabrieleGeneralMeasurementsExcitations with new ESDNew set of excitations after raising the

Quiet time before excitation:
  105   Thu Sep 1 02:13:33 2016 GabrieleOpticsCharacterizationExpected frequencies for the 75 mm disks with flatsHere are the nominal parameters of the
disk with flats

  213   Mon Nov 28 16:02:16 2016 GabrieleGeneralGeneralExpected frequencies for the MIT samples

  26   Wed Jun 29 16:44:17 2016 GabrieleGeneralConfigurationFirst disk eigenfrequencyThe following table shows the lowest eigenfrequency
(Hz) for different sizes of disks

  107   Mon Sep 12 16:00:06 2016 GabrieleGeneralDaily ProgressFirst fully automated measurements of ring downI finished the first version of the automation
software to measure the ring down of the
disk modes. I tested it with the new substrate
  49   Mon Jul 18 17:46:04 2016 GabrieleGeneralDaily ProgressFirst look at QPD signalsHere's the first spectrum of the QPD
X and Y signals, acquired with the digital
system. Roughing and turbo pumps are still
  93   Sat Aug 20 22:18:26 2016 GabrieleGeneralDaily ProgressFirst measured QsUsing the first ring down of the day (GPS 1155754513
+ 3600 seconds), I computed the amplitude
of each of the modes already identified,
  53   Tue Jul 19 17:21:48 2016 GabrieleGeneralDaily ProgressFirst modes excited!We can't generate any arbitary signal
with the real time model, since awg is not
working properly yet. For the moment being
  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
  92   Sat Aug 20 17:01:10 2016 GabrieleGeneralDaily ProgressFirst ring down measurementsEverything is working pretty well. This
morning the pressure was about 1.2e-6 Torr.
I connected the high voltage amplifier and
  292   Mon Feb 6 14:09:07 2017 GabrieleGeneralMeasurementsFirst set of parallel measurements completedThe new laser is still acting up a bit,
with a wandering line moving sometimes inside
the band. Nevertheless, I could perform the
  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:
  82   Sat Aug 13 14:05:02 2016 GabrieleGeneralDaily ProgressFirst work on the measurement user interfaceToday I started programming part of the
user interface that will be used to perform
the measurements. Not much implemented so
  87   Tue Aug 16 11:57:03 2016 GabrieleElectronicsConfigurationFixed cymac3 network and time issueThe cymac3 internal clock was off by about
10 seconds. When I tried to start the NTP
service, I found out that the cymac3 couldn't
  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
  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
  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
  278   Thu Jan 26 17:06:59 2017 GabrieleGeneralDaily ProgressFour fold measurement system installationToday I installed the four GeNS systems
into the chamber, connected the ESD to the
HV feedthrough and put the periscopes in
  282   Mon Jan 30 15:16:54 2017 GabrieleGeneralDaily ProgressFour samples in chamber
checked that the high voltage paths
are working:

the DAC signal
is properly received and amplified by the
  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
  476   Mon Mar 5 11:03:18 2018 Gabriele, AnthonyGeneralMeasurementsFused silica substrated for metallic glass tests2018-03-05

in chamber:

AK_01 in CR1
in CR2
AK_03 in CR3
  873   Tue Jun 9 11:04:28 2020 GabrieleGeneralMeasurementsGaAs S16008052020-06-09

11:00 am
in chamber

GaAs in CR1
in CR2

11:04 am
  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
  56   Thu Jul 21 12:10:14 2016 GabrieleGeneralDaily ProgressGlitch huntingYesterday I could clearly see the glitches
as jumps in the time domain plot of X and
Y signals, and trace them to somewhat harder
  54   Tue Jul 19 20:19:38 2016 GabrieleElectronicsConfigurationGlitches are a digital artifactThe glitches I saw in the data happens
roughly every second, even though not
exactly on the second. They are suddend jumps
  57   Thu Jul 21 14:58:26 2016 GabrieleElectronicsGeneralGlitches are of digital originSo here's the final proof that the
glitches I see are digital:

There is a positive jump
  61   Mon Jul 25 17:44:13 2016 GabrieleElectronicsCharacterizationHigh frequency noise budgetI measured the noise sources limiting the
QPD sensitivity. Unfortunately, I had to
do some MATLAB tricks to get rid of the glitches:
  62   Tue Jul 26 11:45:03 2016 GabrieleElectronicsCharacterizationHigh frequency noise budgetJust to confirm that my noise estimates
make sense, here's a plot of the not-normalized
QPD signal that gives the X motion (sum and
  226   Mon Dec 5 16:35:05 2016 GabrieleElectronicsGeneralHigh voltage relaisWe want to be able to drive any combination
of the four samples in the new setup, by
using only one HV amplifier.
  276   Wed Jan 25 10:02:23 2017 GabrieleElectronicsDaily ProgressHigh voltage system in placeThis morning I installed in the clean room
the high voltage amplifier and the high voltage
relays. Everything is cabled as planned.
  22   Fri Jun 10 13:44:06 2016 GabrieleElectronicsConfigurationHow to setup a workstationInstructions on how to setup a workstation
are available here:

  148   Tue Oct 25 11:10:37 2016 GabrieleGeneralMeasurementsImage of S1600433This is an image of the sample S1600433
under the microscope, courtesy of GariLynn:

  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
  286   Tue Jan 31 16:55:17 2017 GabrieleGeneralDaily ProgressImproved autocenter, excitation not working, wandering line The autocenter script wasn't working
in a very robust way (sometimes the socket
connection to the controller failed, some
  116   Tue Sep 20 15:34:00 2016 GabrieleOpticsDaily ProgressImproved optical lever layoutGoal

Improve the optical setup,
by increasing the response of the QPD to
disk motion.
  270   Fri Jan 20 17:20:20 2017 GabrieleOpticsDaily ProgressInput part of the optical lever setup installed and alignedToday I installed and aligned part of the
optical components for the optical lever
of the new setup. For the moment being I
  272   Mon Jan 23 16:29:52 2017 GabrieleOpticsDaily ProgressInput part of the optical lever setup installed and alignedToday I cabled and installed the four QPD,
in a temporary position. I also assembled
four picomotor mounts that will be used for
  421   Wed Aug 23 14:11:13 2017 Zach, GabrieleElectronicsMeasurementsInstalling ESD Prototype2017-08-23

ESD Prototype design by taping it to the
older design, we then lowered the mount until
  58   Fri Jul 22 14:22:10 2016 GabrieleElectronicsConfigurationInvestigations on the signal jumps[Rolf, Ben, Rich, Gabriele]

Rolf couldn't find any good
explanation on the software side for the
  450   Thu Jan 11 15:40:28 2018 GabrieleGeneralMeasurementsLMA sample (post annealing)2018-01-11

3:35pm in
chamber CR1
3:36pm roughing pump
3:46pm turbo pump on

  432   Thu Oct 5 14:28:35 2017 GabrieleGeneralMeasurementsLMA substrate2017-10-05

2:17pm in

LMA substrate after
cleaning in CR1

  358   Thu Jun 29 13:15:01 2017 Alastair, GabrieleGeneralGeneralLaser polishingWe laser polished S1600546, 547, 548, 549,
550 and 551
  542   Fri Jun 22 10:53:06 2018 AlenaGeneralGeneralLaser failureOne of the HeNe lasers died (the one for
measuring slots CR2 and CR4). It had no outgoing
light when I came in this morning. I connected
  220   Thu Dec 1 11:59:21 2016 Gabriele, AlastairGeneralGeneralLaser polishing Today we laser polished S1600484, S1600485
and S1600486.

  205   Mon Nov 21 16:21:12 2016 Gabriele, AlastairGeneralGeneralLaser polishing of S1600487The sample has been laser polished this
afternoon, 0.5mm/s, average power 23 W.

We moved the lens that focuses the
  208   Tue Nov 22 14:11:38 2016 GabrieleGeneralMeasurementsLaser polishing of bad disk improves Q, but they're still not very goodLaser polishing of a sample from the second
batch (S1600487, bad Q as out of the box)
improves the Q values, but they're still
  101   Mon Aug 22 16:59:13 2016 Gabriele, AlastairOpticsDaily ProgressLaser polishing of the disk edgesWe set up a test facility for laser polishing
the disk edges, using the CO2 laser in the
TCS laboratory. We focused the beam with
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