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  30   Thu Jul 7 16:40:22 2016 Gabriele ElectronicsDaily ProgressQPD boxesTo mitigate the issue of ambient light
pulluting the QPD signal, I mounted the prototype
into a custum built box. This helps a lot.
 2016-07-07_15.55.06.jpg 
  29   Fri Jul 1 15:12:12 2016 GabrieleElectronicsDaily ProgressQPD electronics noise 

I turned out that all the noise
I was seeing in the QPD spectrum was due
 qpd_noise.pngqpd_noise_m.png2016-07-01_15.12.44.jpg 
  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
 2016-06-30_11.08.31.jpg 
  27   Thu Jun 30 16:18:28 2016 GabrieleElectronicsDaily ProgressQPD electronics is workingToday I gave up trying to fix the first
board I populated, and built a second one.
The good news is that it's working as
  
  26   Wed Jun 29 16:44:17 2016 GabrieleGeneralConfigurationFirst disk eigenfrequencyThe following table shows the lowest eigenfrequency
(Hz) for different sizes of disks

 disk_75mm_1mm.pngeigenfrequencies.png 
  25   Tue Jun 28 10:17:28 2016 GabrieleElectronicsDaily ProgressQPD electronicsTransimpendance and whitening are working
properly. I can't get useful signal out
of the differential stages yet. I replaced
  
  24   Fri Jun 24 17:03:47 2016 GabrieleElectronicsDaily ProgressQPD electronicsBetween yesterday and today I populated
one QPD board (based on D1600196),
and started testing it. The transimpedance
 2016-06-24_16.31.48.jpg2016-06-24_16.31.52.jpg 
  23   Thu Jun 16 00:47:42 2016 GabrieleOpticsDaily ProgressQuality factor measurement of a Mark Optics disk at LMA[Massimo Granata (LMA), Quentin Cassar
(LMA), Gabriele] 

This week I'm visiting LMA
 q_factors.pngloss_angle.png2016-06-13_09.50.11.jpg 
  22   Fri Jun 10 13:44:06 2016 GabrieleElectronicsConfigurationHow to setup a workstationInstructions on how to setup a workstation
are available here:

https://nodus.ligo.caltech.edu:8081/Cryo_Lab/1135
  
  21   Tue Jun 7 14:07:55 2016 GabrieleFacilityGeneralRack and workstationI moved the unused rack from the Crackling
Noise lab to the C.Ri.Me lab. It will be
used for the new cymac. I also started putting
 2016-06-07_10.53.30.jpg2016-06-07_10.53.26.jpg 
  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
 2016-06-06_13.29.01.jpg 
  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
 disk_75mm_0.12mm.pngdisk_75mm_1mm.pngdisk_100mm_0.4mm.pngdisk_200mm_0.4mm.png 
  18   Thu May 26 02:51:27 2016 GabrieleElectronicsDesignESD designA preliminary design of the ESD board is
available on the DCC: D1600214
  
  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,
 crime_v1.pdf 
  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
 crime_v1.pdf 
  15   Thu May 19 11:36:04 2016 GabrieleMechanicsDesignA first design of the disk assemblyHere are some screenshots of the disk assembly
and a look at how four of them will sit into
the vacuum chamber. The Solidworks models
 Screen_Shot_2016-05-18_at_3.41.06_PM.pngScreen_Shot_2016-05-18_at_3.40.43_PM.pngScreen_Shot_2016-05-18_at_3.41.25_PM.pngScreen_Shot_2016-05-18_at_3.41.33_PM.pngScreen_Shot_2016-05-18_at_3.41.25_PM.png 
  14   Thu May 19 11:33:44 2016 GabrieleElectronicsDesignOptical lever electronics designThe circuit design sent out for fabrication
is available in the DCC: D1600196
  
  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
  
  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
  
  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 
 qpd.PDFBreakout.PDF 
  10   Tue May 3 11:57:47 2016 GabrieleFacilityDaily ProgressTable and vacuum chambers in the labWe discovered a couple of days ago that
the table was sitting on three legs only
and the fourth one was dangling. I managed
  
  9   Mon May 2 11:46:45 2016 GabrieleFacilityDaily ProgressTable and vacuum chambers in the labElogs for the new Coatin
RIng-down
MEasurement
 2016-04-19_10.35.50.jpg2016-04-21_09.38.33.jpg 
  8   Fri Oct 12 16:23:20 2012 janoschOpticsDaily Progressreassembled setupNothing has happened since Steve, the visiting
highschool teacher, has left. Meanwhile,
some parts of the multi-color BRDF setup
  
  7   Tue Jul 24 10:59:59 2012 janoschOpticsCharacterizationsum of purple and redWe played around with Matlab today. The
first step was to convert light wavelengths
into RGB colors. In this way we can combine
 ImageSum.png 
  6   Fri Jul 20 18:35:42 2012 janoschOpticsCharacterizationpurple improvements and first uncalibrated BSDF curvesToday we improved alignment of the lens-camera
arm. We discovered earlier that this alignment
affects the amount of "snowfall"
 Purple.mp4Red.mp4Purple_BSDF.pngRed_BSDF.png 
  5   Wed Jul 18 18:43:34 2012 janoschOpticsCharacterizationgone with the windHere a little purple video. It starts with
scattering angle around 15deg and stops at
about 80deg. 
 Purple.avi 
  4   Tue Jul 17 18:32:11 2012 janoschOpticsCharacterizationpurple imagesWe have the new 405nm laser pointer. 
The image to the left shows the scattered
light from the red laser, the image to the
 Red_30deg.pngPurple_30deg.png 
  3   Fri Jul 13 20:53:35 2012 janoschOpticsCharacterizationtwo imagesThe following two pictures were taken from
the same angle with green (left) and red
(right) incident laser at an angle of 15deg
 Green.pngRed.png 
  2   Fri Jul 13 10:34:35 2012 janoschOpticsCharacterizationcamera imageWe were confused a bit about how the camera
image changes when you move the arm that
holds the camera and lens around the
  
  1   Wed Jul 11 23:01:01 2012 janoschOpticsCharacterizationstarting the multi-color scatter experimentSteve Maloney, a visiting highschool teacher,
and I have started to set up a new scattering
experiment in the Richter lab. The idea is
 DSCF3148.JPGDSCF3151.JPGDSCF3150.JPG 
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