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  Coating Ring-down Measurement Lab elog, Page 3 of 18  Not logged in ELOG logo
New entries since:Wed Dec 31 16:00:00 1969
ID Dateup Author Type Category Subject Text Attachments
  102   Tue Aug 23 08:46:04 2016 GabrieleGeneralDaily ProgressDaily testsMO03 - edge polished:

Turbo off, QPD centered, before
excitation (60 seconds)
  103   Tue Aug 23 09:21:25 2016 GabrieleGeneralGeneralStatus of Mark Optics disksWe initially received 20 disks (75 mm diameter,
1 mm thickness) from Mark Optics. Here's
their status as of today
  104   Tue Aug 23 09:44:11 2016 GabrieleGeneralGeneralMeasurements on MO-02Two good ring-downs measurements were performed
on MO-02. The first one was already reported
in a previous elog
  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

  106   Sun Sep 11 10:05:33 2016 GabrieleGeneralDaily ProgressNew substrate in the chamberI installed one of the new substrates (with
flats) into the chamber, and started the
pumpdown at about 9:45am LT.
  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
  108   Tue Sep 13 10:33:35 2016 GabrieleGeneralGeneralDisk excitedDisk excited with white uniform noise,
amplitude 5 V, for some tens of seconds.

Excitation off at
  109   Wed Sep 14 13:08:05 2016 GabrieleGeneralGeneralRingdown with roughing pump offAt 1:05pm LT I stopped the roughing pump
and started a ring-down measurement. Pump
restarted at 2:18pm LT.
  110   Wed Sep 14 20:17:33 2016 GabrieleGeneralGeneralBand-limited excitationExcitation started at 20:15:30LT, 20 seconds
long. The excitation is band-limited (10
Hz) centered around each of the predicted
  111   Thu Sep 15 08:13:20 2016 GabrieleGeneralGeneralPump had no effect on ring down measurementsThe plot below shows three measurements
of the Q of the same disk: during the first
two the roughing pump was on, while during
  112   Thu Sep 15 08:27:57 2016 GabrieleGeneralGeneralNew band-limited excitationSame as in elog #110,
but now the amplitude is proportional to
frequency squared:
  113   Thu Sep 15 11:23:13 2016 GabrieleFacilityGeneralChamber openTurbo pump off and spinning down at 9:37am
LT. Pumo completely stopped at 11:15am LT

Openend the chamber and removed
  114   Thu Sep 15 15:15:10 2016 GabrieleGeneralGeneralEdge effect on lossesI made a COMSOL model that can compute
the distribution of elastic energy for each
mode, dividing it into:
  115   Fri Sep 16 14:06:43 2016 GabrieleGeneralGeneralPump had no effect on ring down measurementsSame plot as below, but this time with
estimated 95% confidence intervals for the
Q values, as obtained from the fit only.
  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.
  117   Tue Sep 20 16:12:09 2016 GabrieleGeneralGeneralPump downAs a test, I installed MO1 (the disk with
the burn mark, used for the first edge laser
polishing test) and started pumping down.
  118   Tue Sep 20 16:43:58 2016 GabrieleGeneralGeneralExcitation and ring downThe pressure is at abour 3e-6 Torr. I centered
the QPD and started an excitation. The HV
amplifier manual states that the driver can
  119   Wed Sep 21 08:12:13 2016 GabrieleGeneralGeneralExcitation and ring downNew excitation (2000V) at about 8:06am.
Had to recenter the QPD again after the excitation.

Engaged the 500Hz high pass filter
  120   Wed Sep 21 14:42:47 2016 GabrieleGeneralGeneralSerialized (etched) disk installedJust for fun, I installed the disk thas
has been etched in the center with "1234".
I figured out that the ESD PCB was probably
  121   Thu Sep 22 09:49:21 2016 GabrieleGeneralGeneralRing-down of etched diskQPD centerd, quiet data, light off, one
minute from

PDT: 2016-09-22 09:46:29.393609
  122   Thu Sep 22 13:39:40 2016 GabrieleOpticsConfigurationUpdated design for the new C.Ri.Me. setupToday I measured the amount of space available
on the table for the new (4-fold) C.Ri.Me.
setup. It's 1050 x 1220 mm, with the
  123   Thu Sep 22 15:00:49 2016 GabrieleElectronicsConfigurationEpics values now saved to framesI was looking at some past trend data and
discovered that EPICS values were not written
to the frames. I added the following two
  124   Fri Sep 23 08:11:48 2016 GabrieleMechanicsDaily ProgressTest of the disk retaining ring motionIn brief, it doesn't work. The magnets
and coils are strong enough to push up the
ring with a sample inside, but the friction
  125   Fri Sep 23 08:33:39 2016 GabrieleElectronicsConfigurationEpics values now saved to framesNow EPICS values are saved to frames, but
they are all zero! I noticed that we always
had the same problems with the cymac2 too.
  126   Mon Sep 26 15:54:01 2016 GabrieleFacilityConfigurationMoved vacuum controllersI moved the turbo pump controller out of
the clean room. Also, I installed the gauge
controller on the Cymac rack.
  127   Mon Sep 26 15:59:09 2016 GabrieleOpticsDaily ProgressQPD auto centeringWe have a few motorized mounts (with New
Focus picomotors) and one controller (an
old New Focus 8753, six axis total) that
  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
  129   Tue Sep 27 14:54:53 2016 GabrieleElectronicsConfigurationEpics values now saved to framesApparently, there was a mismatch in the
configuration, and DAQD was adding a wonderful
16 Hz comb all over the spectrum.
  130   Tue Sep 27 15:10:59 2016 GabrieleGeneralMeasurementsRing-down of etched diskQuiet (roughing pump off, lights off):
60 seconds from
PDT: 2016-09-27 15:05:30.805667 PDT
  131   Wed Sep 28 10:26:58 2016 ranaGeneralGeneralreferences on ideal glassesSome easy to read reviews on
thin films and ideal glass for people getting
started in this Q measuring game.

  132   Thu Sep 29 15:40:45 2016 GabrieleOpticsDesignBeam profile of new 21mW HeNe laser and tweak of optical lever designI measured the beam profile of the new
Thorlabs HeNe (21.8 mW measured). The beam
waist is 355 microns, very close to the laser
  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.
  134   Tue Oct 18 16:29:37 2016 GabrieleGeneralMeasurementsS1600433S1600433, annealing run 10/10/2016


in the measurement system, chamber closed
down started at 4:27pm LT
  135   Tue Oct 18 16:52:16 2016 GabrieleGeneralMeasurementsSample inspections from annealing run 10/10/2016LIGO-T1600466

S1600432 shows some residual
on face, close to the edge, probably from
  136   Wed Oct 19 13:35:23 2016 GabrieleGeneralMeasurementsS1600438S1600438, not annealed, as received
from Mark Optics


pump switched off at 11:42am (2016-10-19)
  137   Wed Oct 19 16:40:24 2016 sults:GeneralMeasurementsS1600349S1600439, not annealed, as received
from Mark Optics


and balanced, pump down started at 4:38pm
  138   Wed Oct 19 17:08:47 2016 GabrieleGeneralMeasurementsS1600433 vs S1600438
S1600433 has been annealed, was
contaminated by the iron oxide, and it was
cleaned using first contact. No residual
  139   Thu Oct 20 11:04:03 2016 GabrieleGeneralMeasurementsSample with flame polished edgesSample with edges flame polished in Glasgow


the chamber and balanced at 11am. Pump down
started at 11:00am.
it looks like
  140   Thu Oct 20 14:38:24 2016 GabrieleCleanDaily ProgressCleaning of S1600433 and S1600438Samples #433 (annealed and cleaned) and
#438 (as received from Mark Optics) are now
with GariLynn for deep cleaning.
  141   Fri Oct 21 13:45:21 2016 GabrieleGeneralMeasurementsS1600447Sample S1600447, as received from Mark
Optics, second batch


into the chamber, pumping down started at
  142   Fri Oct 21 14:03:17 2016 GabrieleGeneralVacuumRoughing pump movedI moved the roughing pump out of the clean
room, adding an extension hose.

  143   Fri Oct 21 15:27:15 2016 GabrieleElectronicsConfigurationRemoved low pass filter in SUMI removed the low pass filter in the QPD
SUM signal, used for normalization. This
reduced a lot the bump at ~20kHz due to laser
  144   Mon Oct 24 10:26:30 2016 GabrieleGeneralMeasurementsS1600439S1600439, post annealing

before annealing reported in elog 137.
  145   Mon Oct 24 14:33:46 2016 GabrieleGeneralMeasurementsEffect of annealing: Q increasesS1600439 has been measured as received
(before annealing, elog
137) and after annealing (elog
  146   Mon Oct 24 16:32:01 2016 GabrieleGeneralMeasurementsS1600448Sample S1600447, as received from
Mark Optics, second batch

chamber, pumping down at 4:30pm (2016-10-24)
  147   Tue Oct 25 09:12:31 2016 GabrieleGeneralMeasurementsComparison of first and second batchThe plot below compares a sample from the
first batch and two samples from the second
batch. All samples are as received from Mark
  148   Tue Oct 25 11:10:37 2016 GabrieleGeneralMeasurementsImage of S1600433This is an image of the sample S1600433
under the microscope, courtesy of GariLynn:

  149   Thu Oct 27 14:02:38 2016 AlenaGeneralGeneralAnnealingAnnealing run (447-448) on 3" wafers
- Crime 10/27/2016 https://dcc.ligo.org/T1600485-v1

  150   Fri Oct 28 21:20:48 2016 GabrieleGeneralMeasurementsS1600447 post annealingInstallation

I had some problems
in installing the wafer. I balanced it and
started the pump down a couple of times,
  151   Sat Oct 29 10:12:39 2016 GabrieleGeneralMeasurementsS1600448 post annealing2016-10-29

at 10:00am 10/29
sample installed,
pumping down started at 10:12am, turbo pump
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