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  Coating Ring-down Measurement Lab elog, Page 16 of 18  Not logged in ELOG logo
New entries since:Wed Dec 31 16:00:00 1969
ID Date Author Type Category Subject Text Attachments
  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.



  
  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
  
  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
  
  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
 2016-09-26_15.44.02.jpg2016-09-26_15.43.45.jpgautocenter.png 
  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.
 2016-09-26_15.44.13.jpg 
  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.
  
  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
  
  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
  
  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
 crime_v2.pdf 
  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
  
  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
  
  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
  
  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
  
  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.
  
  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.
 beam_profile.png2016-09-19_11.33.48.jpg2016-09-20_15.50.21.jpglayoutpng.png 
  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.
 summary_q_with_conf_intervals.png 
  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:
 losses_fit_edge.pnglosses_fit_edge_surface.pnglosses_fit_all.png 
  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
  
  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:
  
  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
 pump_on_off.png 
  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
  
  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.
  
  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
  
  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
 step_1.pngstep_2.pngmain.pngScreenshot-Ringdown-1.png 
  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.
  
  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

 allmodes_aggregated.pdf 
  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
 7x 
  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
  
  102   Tue Aug 23 08:46:04 2016 GabrieleGeneralDaily ProgressDaily testsMO03 - edge polished:

Turbo off, QPD centered, before
excitation (60 seconds)
 noise.png 
  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
 2016-08-22_14.47.47.jpg2016-08-22_13.52.02.jpg 
  100   Mon Aug 22 12:01:52 2016 GabrieleGeneralGeneralTests of the dayDisk excited at 12:01pm. Exited the room
at 12:03pm.

Opened the chamber at about 2:30pm,
  
  99   Mon Aug 22 08:29:24 2016 GabrieleGeneralDaily ProgressNew testRestarted roughing and turbo pump at about
8:10am.

  
  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
  
  97   Sun Aug 21 17:16:03 2016 GabrieleGeneralDaily ProgressRing down measurement with new diskAfter fixing the setup, the measurement
with the new disk looks great. After more
than one hour the first two modes are still
 22x 
  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
  
  95   Sun Aug 21 13:45:56 2016 GabrieleOpticsDaily ProgressWierd behavior of ring downs and Improved setupThe last two ring downs I measured today
showed a weird behavior of the lowest modes:

 second_ring_downs.pngthird_ring_downs.png2016-08-21_08.46.11.jpg2016-08-21_13.29.24.jpg2016-08-21_13.29.32.jpg 
  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
  
  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,
 22x 
  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
 modes.pdf 
  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
 10x 
  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
 2016-08-19_10.54.51.jpg2016-08-19_12.07.29.jpg2016-08-19_12.38.42.jpg 
  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.
 2016-08-18_18.07.29.jpg2016-08-18_18.07.42.jpg 
  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
 2016-08-17_15.29.40.jpg2016-08-17_15.30.05.jpg 
  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
  
  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
 2016-08-16_10.25.05.jpg 
  85   Sun Aug 14 18:26:19 2016 GabrieleGeneralGeneralPlans for the automatic mode searchHere's how I imagine the mode search
to proceed:


the user select the list
  
  84   Sun Aug 14 18:13:52 2016 GabrieleElectronicsDaily ProgressProgress on the user interfaceSome progress on writing the user interface:

 crime1.pngcrime2.png 
  83   Sun Aug 14 11:40:29 2016 GabrieleElectronicsDaily ProgressSome python code Today I wrote some auxiliary functions
that will be useful for the measurement system:


noise.py: set of functions
 noise.pngnoise_multi_band.pngpeak.png 
  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
 Screenshot-C.Ri.Me..pngcrime.png 
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