40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  Coating Ring-down Measurement Lab elog, Page 4 of 18  Not logged in ELOG logo
ID Date Author Type Category Subjectup Text Attachments
  291   Mon Feb 6 11:19:13 2017 GabrieleOpticsDaily ProgressLaser swapThe Thorlabs laser has been misbehaving
for the whole weekend. Even after many days
being continuosly on, the wandering line
  295   Tue Feb 7 16:16:37 2017 GabrieleOpticsDaily ProgressLasersThe high power lasers I tested so far (the
Thorlabs 21mW and the JDSU 1125P) are noisy:
they both have wandering lines that from
  64   Wed Jul 27 10:19:36 2016 GabrieleElectronicsConfigurationLast finding in the signal jump sagaThis plot shows a signal which is generated
purely digitally inside a code that I was
  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,
  19   Fri May 27 02:09:37 2016 GabrieleMechanicsCharacterizationLowest usable mode of fused silica disksI did some FEA simulation of fused silica
disks, to identify the lowest usable eigenmode.
By usable I mean a mode that has zero elastic
  173   Thu Nov 10 14:13:34 2016 gabrieleElectronicsConfigurationMATLAB code to control Thorlabs stagesTo be used to automate the laser polishing.  move_complete.mthrolabs_activex.manimation.mdraw_wafer.m 
  223   Fri Dec 2 14:05:47 2016 GabrieleGeneralGeneralMIT bare disk losses reproduced with edge and surface lossesThe measured losses of the MIT bare disk
show a remarkable split into families. The
plot belo shows the measured total loss angles
  334   Wed Mar 29 11:57:09 2017 GabrieleGeneralMeasurementsMIT sample2017-03-29

in chamber CR0, balanced
roughing pump on
12:00pm, turbo
  212   Mon Nov 28 15:06:09 2016 GabrieleGeneralMeasurementsMIT sample 1 (bare disk)2016-11-28

removed the retaining ring and the alignment
3:05pm, 100mm/0.5mm disk
  214   Tue Nov 29 11:26:46 2016 GabrieleGeneralMeasurementsMIT sample 2 (disk with 4 1"/0.1mm glued blanks)2016-11-19

  215   Tue Nov 29 16:42:51 2016 GabrieleGeneralMeasurementsMIT sample 3 (disk with 4 0.5"/0.125" glued blanks)2016-11-29

  234   Wed Dec 7 09:59:59 2016 GabrieleGeneralMeasurementsMIT sample 3 (disk with 4 0.5"/0.125" glued blanks) second round2016-12-07

retaining ring and pins, aligned optical
setup to horizontal reference
  218   Wed Nov 30 10:02:20 2016 GabrieleGeneralMeasurementsMIT sample 4 (disk with 3 1"/0.1mm glued blanks)2016-11-30

  255   Fri Jan 6 11:23:10 2017 GabrieleGeneralMeasurementsMark Optics 4This is one of the samples we got
from the first batch, no flats, edge not
  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
  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
  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
  210   Wed Nov 23 14:16:59 2016 AlenaGeneralGeneralMicroscope inspectionMicroscope inspection of samples:

S1600487  https://dcc.ligo.org/S1600487-v7

S1600438 https://dcc.ligo.org/S1600438
  204   Mon Nov 21 11:46:57 2016 GabrieleGeneralGeneralMicroscope inspection of 439 and 487S1600439

This is the sample
that was CO2 polished (198)
and measured after polishing (197,
  201   Fri Nov 18 15:48:09 2016 GabrieleGeneralMeasurementsMicroscope inspection of CO2 polished samplesS1600470

For reference, this
sample has not been CO2 polished, but it
has been annealed and measured. It has quite
  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
  403   Thu Aug 10 11:32:09 2017 GabrieleGeneralMeasurementsMode peak amplitudes with reference ESDThe uncoated, annealed and CO2 polished
substrate S1600541 is installed in chamber
CR0. This morning I performed a quick excitation:
  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
  59   Mon Jul 25 12:24:06 2016 GabrieleElectronicsConfigurationMore on the signal jumpsHere are two more tests I did this morning

removed the DAC card from
the cymac and the models, and restarted everything:
  73   Tue Aug 2 16:00:32 2016 GabrieleElectronicsCharacterizationMore on the signal jumpsSo I’m
sending a 1.123 Hz sinusoid into the ADC,
  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.
  42   Thu Jul 14 17:06:47 2016 GabrieleElectronicsConfigurationNetworkingThe laboratory workstation is coatings.ligo.caltech.edu

The RTS is cymac3.ligo.caltech.edu

I set up a ssh-mount of the /opt/rtcds/userapps
  338   Fri Apr 7 16:19:03 2017 GabrieleOpticsDaily ProgressNew 1103P laser installedThis afternoon I installed the new Lumentum
(former JDSU) HeNe laser, model 1103P in
  323   Tue Feb 28 14:20:50 2017 GabrieleGeneralMeasurementsNew MIT sample #12017-02-28

installed in CR0, balanced, with 1/2"
inserts facing down

It looks
  328   Fri Mar 3 13:01:59 2017 GabrieleGeneralMeasurementsNew MIT sample #22017-03-03

in chamber, realigned optical lever to get
as close as possible to the edge of the disk
  330   Tue Mar 7 11:09:33 2017 GabrieleGeneralMeasurementsNew MIT sample #32017-03-07

in chamber CR0
11:09am, roughing
pump on
11:23am turbo pump on
  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:
  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
  266   Thu Jan 19 14:16:53 2017 GabrieleMechanicsDesignNew concept for retaining ring motionSince my experiment with coil and magnets
didn't work out very well, here's
a new concept for the motion of the four
  94   Sun Aug 21 08:51:22 2016 GabrieleGeneralDaily ProgressNew disk installedVented the chamber. Installed a new disk
(MO 03). The one I measured yesterday is
now named MO 02 and it is the one with the
  554   Thu Jul 26 15:33:00 2018 AlenaGeneralGeneralNew laser instaled for the old chanber cr0Installed a new HeNe laser for the old
chamber cr0. No major alignement was required.
The laser mount restored the alinement. Will
  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.
  96   Sun Aug 21 15:36:16 2016 GabrieleGeneralDaily ProgressNew testRoughing pump stopped at about 3:30:30pm.
HV amplifier on at 3:33:30pm, excitation
at 3:35:30pm. Recentered QPD at 3:36pm
  98   Sun Aug 21 17:41:34 2016 GabrieleGeneralDaily ProgressNew testI checked the status at about 5:20pm, the
turbo pump was in error and spinning down,
since the roughing pump has been off for
  99   Mon Aug 22 08:29:24 2016 GabrieleGeneralDaily ProgressNew testRestarted roughing and turbo pump at about

  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.
  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)
  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).
  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
  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
  37   Mon Jul 11 15:21:12 2016 GabrieleGeneralDaily ProgressOne disk installed into the chamber[Alena, Gabriele]

We attached one of the silicon
lenses to a 1" optical post using some
  14   Thu May 19 11:33:44 2016 GabrieleElectronicsDesignOptical lever electronics designThe circuit design sent out for fabrication
is available in the DCC: D1600196
  280   Fri Jan 27 14:56:55 2017 GabrieleOpticsDaily ProgressOptical lever setup completedThe four optical levers are completely
installed and aligned to a horizontal reference.

  16   Fri May 20 15:18:58 2016 GabrieleOpticsDesignOptical levers layoutAttached a first layout of the optical
lever systems. The beam spot radius on the
QPD is about 0.8 mm, and the lever arm length
  17   Sun May 22 23:40:45 2016 GabrieleOpticsDesignOptical levers layoutAn improved design is attached. I modified
the input telescope to avoid using shor focal
length lenses, to make it less critical,
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