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 2 of 18  Not logged in ELOG logo
ID Date Author Type Category Subjectup Text Attachments
  551   Wed Jul 25 11:23:44 2018 AlenaGeneralGeneralCR14 re-alignementAligned CR14 chamber back to 3" disks.  20180725_111415.jpg 
  60   Mon Jul 25 15:35:31 2016 GabrieleOpticsCharacterizationCalibration of the QPD in physical unitsThe
equations below are wrong. Please refer to https://nodus.ligo.caltech.edu:8081/CRIME_Lab/116
  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
  217   Tue Nov 29 17:06:13 2016 GabrieleElectronicsConfigurationChanged whitening filters of four more boardsI modified four more QPD boards to implement
the new whitening filters detailed in elog 207.
  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.
  68   Thu Jul 28 14:01:27 2016 AlenaGeneralDaily ProgressClean roomOrdered the clean room (hardware+hepa filters)
and vacuum gauges
  90   Fri Aug 19 13:46:55 2016 Alena, Calum, Jon, Liz, Steve, GabrieleFacilityDaily ProgressClean room and vacuum completeThis morning we installed the clean room
curtains and washed them. It turns out that
the air filters are supposed to be powered
  88   Wed Aug 17 16:41:05 2016 Gabriele, AlenaCleanDaily ProgressClean room construction progressThe clean room frame is built and secured
to the floor and wall. Panels are being installed
on the ceiling and back. Also, the optical
  89   Thu Aug 18 18:15:18 2016 Gabriele, AlenaCleanDaily ProgressClean room construction progressCeiling, back and side panels are installed.
The air filters have been cabled and connected
to the power supply.
  689   Mon May 13 18:37:47 2019 aaronCleanGeneralClean room gearMon May 13 18:37:37 2019

Entered CRIME lab to borrow 4x
hair nets and face masks. Can you 
  696   Mon May 20 10:35:45 2019 aaronCleanGeneralClean room gearAaron,

There is a buy list of approved
clean room supplies posted here https://dcc.ligo.org/LIGO-E1300399.
  86   Tue Aug 16 11:53:30 2016 Alena, GabrieleCleanDaily ProgressClean room progressSome progress on the cleam room: bar fixed
to the wall, some more structure built, filters
in place. We had to (literally) work around
  221   Fri Dec 2 10:56:40 2016 GabrieleGeneralMeasurementsCleaning improves the Q values a bitThe plot below compares the measured Q
values of S1600433 right after annealing,
and after GariLynn cleaned it. Q values are
  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.
  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
  20   Mon Jun 6 13:35:36 2016 GabrieleElectronicsGeneralComponentsThe PCBs for the QPD circuit and ADC interface
are here and look ok. All electronics components
are also here (except for the ADC connector
  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
  34   Fri Jul 8 16:49:11 2016 GabrieleElectronicsConfigurationCyMAC In the last days Jamie installed the patched
kernel to run the real time system (RTS)
on the new CyMAC. Today (with Jamie's
  28   Thu Jun 30 17:23:54 2016 GabrieleElectronicsDaily ProgressCymacI got two new ADC and DAC boards from Rolf,
with the correct PCIe interface. I installed
them into the cymac and checked that the
  35   Mon Jul 11 08:49:25 2016 GabrieleElectronicsConfigurationCymac RTS configurationI copy here parts of an email from Jamie
with instructions on how to run the RTS on
the cymac:
  40   Thu Jul 14 15:30:48 2016 ericqElectronicsConfigurationCymac RTS configurationWe played around a bit with the cymac,
in efforts to make things better.

We disabled some more fancy-sounding
  102   Tue Aug 23 08:46:04 2016 GabrieleGeneralDaily ProgressDaily testsMO03 - edge polished:

Turbo off, QPD centered, before
excitation (60 seconds)
  74   Mon Aug 8 10:42:46 2016 GabrieleGeneralGeneralDependency of eigenmode frequencies on thickness and diameterI ran a set of COMSOL simulations to determine
the dependency of the frequency of each eigenmode
on the disk thickness and diameter, within
  11   Fri May 6 14:20:43 2016 GabrieleElectronicsDesignDesign of optical lever electronics For the optical levers we are going to
use the same QPD that are used in aLIGO optical
levers (see T1600085 and 
  12   Sun May 8 13:35:04 2016 ranaElectronicsDesignDesign of optical lever electronics Koji, Rich, and I recently came up with
a new QPD design which is better for general
lab use than the aLIGO ones (which have a
  13   Tue May 10 13:32:17 2016 GabrieleElectronicsDesignDesign of optical lever electronics After a very useful discussion with Rich
this morning, I think the circuit based on
aLIGO optical levers design should be good
  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
  91   Fri Aug 19 19:05:01 2016 GabrieleOpticsDaily ProgressDisk installed into the chamberI assembled the disk suspension sytem and
installed into the chamber. Although I don't
have the magnets and coils, I installed the
  319   Fri Feb 24 14:44:22 2017 GabrieleGeneralGeneralDisk modelIt's possible to build an analytical
model of the resonant frequencies of a simple
thin disk. For example, see J. Sound
  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
  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
  411   Wed Aug 16 10:04:24 2017 ZachElectronicsModelingESD along edge2017-08-16

I placed
created a very narrow ESD placed along the
edge of the sample. The thought behind this
  18   Thu May 26 02:51:27 2016 GabrieleElectronicsDesignESD designA preliminary design of the ESD board is
available on the DCC: D1600214
  405   Thu Aug 10 13:36:08 2017 Gabriele, ZachMechanicsConfigurationESD moved closer to disk in CR0We first measured the distance of the ESD
from the disk in the test chamber (CR0).
We had to remove the retaining ring to have
  406   Fri Aug 11 09:22:21 2017 GabrieleMechanicsConfigurationESD moved closer to disk in CR0The plots below compare the SNR and peak
amplitude of all excited modes, in the new
and old configuration. The new confgiuration
  420   Fri Aug 18 15:10:23 2017 Zach, GabrieleElectronicsModelingESD prototype2017-08-18

We created
a prototype of PCB for the ESD design. Unfortunately
the orientation of the two combs was flipped,
  417   Fri Aug 18 10:50:53 2017 ZachElectronicsModelingESD's with positive voltage2017-08-18

With both
electrodes driven at a positive voltage,
the results are still an improvement over
  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:
  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
  396   Tue Aug 8 10:18:30 2017 GabrieleGeneralMeasurementsEffect 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
  395   Tue Aug 8 09:58:34 2017 GabrieleGeneralMeasurementsEffect 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
  243   Thu Dec 15 11:58:55 2016 GabrieleGeneralGeneralEffect of clip fingerprints on dilution factorThe disks coated at Montreal are hold with
three small clips. Therefore there are three
small regions close to the edge that are
  344   Tue May 16 13:44:01 2017 GabrieleGeneralGeneralEffect of meshing on dilution factor simulationI ran a series of COMSOL simulations to
compute the dilution factors of a coated
disk with the dimensions we are currently
  43   Fri Jul 15 16:05:07 2016 GabrieleElectronicsDaily ProgressElectrostatic actuator installedUsing the already installed high voltage
feedthrough, I cabled one of the electrostatic
actuators (1mm gap between electrodes) and
  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
  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.
  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.
  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
  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
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