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ID Date Author Type Categoryup Subject Text Attachments
  14278   Tue Nov 6 19:41:46 2018 JonOmnistructure c1vac1/2 replacementThis afternoon I started setting up the
Supermicro 5017A-EP that will replace c1vac1/2.
Following Johannes's procedure in 
  
  14282   Wed Nov 7 19:17:18 2018 JonOmnistructure modbusIOC is running on c1vac replacementToday I finished setting up the server
that will replace the c1vac1/2 machines.
I put it on the martian network at the unassigned
  
  14287   Fri Nov 9 22:24:22 2018 JonOmnistructure Wiring of Vacuum Acromag Chassis CompleteWiring of the power, Ethernet, and indicator
lights for the vacuum Acromag chassis is
complete. Even though this crate will only
 IMG_2987.jpgIMG_2985.jpgIMG_2986.jpg 
  14296   Wed Nov 14 21:34:44 2018 JonOmnistructure Vacuum Acromags installed and testedAll 7 Acromag units are now installed in
the vacuum chassis. They are connected to
24V DC power and Ethernet.
 IMG_3003.jpg 
  14308   Mon Nov 19 22:45:23 2018 JonOmnistructure Vacuum System SubnetworkI've set up a closed subnetwork for
interfacing the vacuum hardware (Acromags
and serial devices) with the new controls
  
  14309   Mon Nov 19 23:38:41 2018 JonOmnistructure Vacuum Acromag Channel AssignmentsI've completed bench testing of all
seven vacuum Acromags installed in a custom
rackmount chassis. The system contains
 Binary_IO_Channel_Assignments.pdf 
  14315   Sun Nov 25 17:41:43 2018 JonOmnistructure Vacuum Controls Upgrade - Status and PlansNew hardware has been installed in the
vacuum controls rack. It is shown in the
below post-install photo.
 rack_photo.jpg 
  14320   Mon Nov 26 21:58:08 2018 JonOmnistructure Serial Vacuum SignalsAll the serial vacuum signals are now interfaced
to the new digital controls system. A set
of persistent Python scripts will query each
 GP307_relays.jpeg 
  14420   Tue Jan 29 16:12:21 2019 ChubUpdate  The foam in the cable tray wall passage
had been falling on the floor in little bite-sized
pieces, so I investigated and found a fiber
  
  14435   Tue Feb 5 10:22:03 2019 chubUpdate oil added to RP-1 & 3I added lubricating oil to roughing pumps
RP1 and RP3 yesterday and this morning. 
Also, I found a nearly full 5 gallon jug
  
  14437   Wed Feb 6 10:07:23 2019 ChubUpdate pre-construction inspectionThe Central Plant building will be undergoing
seismic upgrades in the near future. 
The adjoining north wall along the Y arm
  
  14476   Fri Mar 8 08:40:26 2019 AnjaliConfiguration Frequency stabilization of 1 micron sourceThe schematic of the homodyne configuration
is shown below.

Following are the list of components
 Homodyne_setup.png 
  14621   Sat May 18 12:19:36 2019 KruthiUpdate CCD calibration and telescope designI went through all the elog entries related
to CCD calibration. I was wondering
if we can use Spectralon diffuse
 6x 
  14626   Mon May 20 21:45:20 2019 MilindUpdate Traditional cv for beam spot motionWent through all of Pooja's elog posts,
her report and am currently cleaning up her
code and working on setting up the simulations
  
  14782   Fri Jul 19 22:48:08 2019 KruthiUpdate Dataviewer errorI'm not able to get trends of
the TM adjustment test that Rana had
asked us to perform, from the dataviewer.
  
  14783   Sat Jul 20 01:03:37 2019 gautamUpdate Dataviewer errorWhat channels are you trying to read?




  
  14869   Tue Sep 10 16:10:40 2019 ChubUpdate Rack UpdateStill removing old cable, terminal blocks
and hardware.  Once new strain reliefs
and cable guides are in place, I will need
 20190910_154018.jpg20190910_154006.jpg 
  15225   Wed Feb 26 17:17:17 2020 YehonathanUpdate Arms DC loss measurements{Yehonathan, Gautam}

In order to measure the loss in
the arm cavities in reflection, we use the
 6x 
  15729   Thu Dec 10 17:12:43 2020 JonUpdate New SMA cables on orderAs requested, I placed an order for an
assortment of new RF cables: SMA male-male,
RG405.
  
  15739   Sat Dec 19 00:25:20 2020 JonUpdate New SMA cables on orderI re-ordered the below cables, this
time going with flexible, double-shielded
RG316-DS.
  
  15740   Sat Dec 19 02:42:56 2020 KojiUpdate New SMA cables on orderOur favorite (flexible) RF cable is Belden's
1671J (Jacketed solder-soaked coax cable).
It is compatible RG405. I'm not sure
  
  16308   Thu Sep 2 19:28:02 2021 KojiUpdate This week's FB1 GPS Timing Issue SolvedAfter the disk system trouble, we could
not make the RTS running at the nominal state.
A part of the troubleshoot FB1 was rebooted.
  
  16339   Thu Sep 16 14:08:14 2021 Ian MacMillanFrogs TourI gave some of the data analysts a look
around because they asked and nothing was
currently going on in the 40m. Nothing was
  
  2653   Wed Mar 3 18:32:25 2010 AlbertoUpdate40m Upgrading11 MHz RFPD elctronics** Please
add LISO file w/ component values.
 
 rfpd11_v2_TF.pdfrfpd11_v2_Noise.pdf 
  2655   Thu Mar 4 08:43:35 2010 AlbertoUpdate40m Upgrading11 MHz RFPD elctronics


   
        
            
 rfpd11_v2.fil 
  2656   Thu Mar 4 19:53:56 2010 AlbertoUpdate40m Upgrading11MHz PD designed adjusted for diode's resistance; 55 MHz RFPD designedAfter
reading this study done
 6x 
  2657   Thu Mar 4 22:07:21 2010 ranaUpdate40m Upgrading11MHz PD not yet designedUse 10 Ohms for the resistance - I have
never seen a diode with 25 Ohms.
p.s. PDFs can be joined together
  
  2704   Tue Mar 23 22:46:43 2010 AlbertoUpdate40m UpgradingREFL11 upgradedI modified REFL11 according to the changes
lsited in this
schematic (see wiki  / Upgrade 09
 2010-03-23_REFL11_model_to_meas_comparison.png 
  2711   Wed Mar 24 14:57:21 2010 AlbertoUpdate40m UpgradingREFL11 upgraded 
 Hartmut suggested a possible
explanation for the way the electronics transfer
  
  2715   Thu Mar 25 17:32:42 2010 AlbertoUpdate40m UpgradingREFL55 UpgradedI upgraded the old REFL199 to the new REFL55.
To do that I had to replace the old
photodiode inside, switching to a 2mm one.
 2010-03-25_REFL55_model_to_meas_comparison.png2010-03-25_REFL55_model_to_meas_comparison.png 
  2761   Sat Apr 3 19:54:19 2010 AlbertoUpdate40m UpgradingREFL11 and REFL55 PDs Noise SpectrumThese are the dark noise spectrum that
I measured on the 11MHz and 55MHz PD prototypes
I modified.
 2010-04-03_REFL11_darknoise.png2010-04-03_REFL55_darknoise.png 
  2767   Mon Apr 5 10:23:40 2010 AlbertoUpdate40m UpgradingREFL11 Low Frequency Oscilaltion ReducedAfter adding an inductor L=100uH and a
resistor R=10Ohm in parallel after the OP547A
opamp that provide the bias for the photodiode
 2010_04_05_REFL11_darknoise_with_100uH_coil_10ohm_res.png2010_04_05_REFL11_darknoise_wide_freq_window_lid_open-closed.png2010_04_05_REFL11_darknoise_wide_freq_window_lid_open-closed.png 
  2782   Thu Apr 8 10:17:52 2010 AlbertoUpdate40m UpgradingREFL11 Noise Vs PhotocurrentFrom the measurements of the 11 MHz RFPD
at 11Mhz I estimated a transimpedance of
about 750 Ohms. (See attached plot.)
 2010_04_05_REFL11_ShotnoiseVsPhotocurrent.png 
  2783   Thu Apr 8 10:24:33 2010 AlbertoUpdate40m UpgradingREFL11 Noise Vs Photocurrent


   
        
            
  
  2784   Thu Apr 8 20:53:13 2010 KojiUpdate40m UpgradingREFL11 Noise Vs PhotocurrentSomething must be wrong. 
1. Physical Unit is wrong for the
second term of "Vn = Vdn + Sqrt(2 e
  
  2785   Fri Apr 9 06:45:28 2010 AlbertoUpdate40m UpgradingREFL11 Noise Vs Photocurrent


   
        
            
  
  2789   Mon Apr 12 16:20:05 2010 AlbertoConfiguration40m UpgradingREFL55 improvedDuring the commissioning of the AS55
PD, I learned how to get a much better rejection
of the 11MHz modulation.
So I
 2010-04-12_REFL55_TF_model_to_meas_comparison.png 
  2790   Mon Apr 12 17:09:30 2010 AlbertoUpdate40m UpgradingREFL11 Noise Vs Photocurrent


   
        
            
 2010-04-09_REFL11NoiseMeasurements.png 
  2795   Mon Apr 12 22:44:30 2010 KojiUpdate40m UpgradingREFL11 Noise Vs PhotocurrentData looks perfect ... but the fitting
was wrong.
Vn = Vdn + Z * sqrt( 2 e Idc )
  
  2882   Wed May 5 16:32:39 2010 AlbertoUpdate40m UpgradingNew REFL55 PD, 11MHz rejectionHere's the (calibrated) transimpedance
of the new REFL55 PD.
T(55.3) / T_(11.06) = 93 dB
 2010-05-05_REFL55_CalibratedOpticalResponse0-60MHz.png 
  2886   Thu May 6 16:18:37 2010 AlbertoUpdate40m UpgradingNew improved design for the 11MHz photodiodeAfter munching analytical models, simulations,
measurements of photodiodes I think I got
a better grasp of what we want from them,
 pox11.pdf 
  2893   Thu May 6 19:57:26 2010 AlbertoUpdate40m UpgradingNew improved design for the 11MHz photodiode


   
        
            
 pox11.pdf 
  2894   Fri May 7 11:21:49 2010 kojiUpdate40m UpgradingNew improved design for the 11MHz photodiodeHow much is the width?

  
  2896   Fri May 7 18:18:02 2010 AlbertoUpdate40m UpgradingNew improved design for the 11MHz photodiode


   
        
            
  
  2897   Fri May 7 19:02:27 2010 ranaUpdate40m UpgradingNew improved design for the 11MHz photodiodeTo measure the width of a resonance, the
standard method is to state the center frequency
and the Q. Use the definition of Q from the
  
  2902   Mon May 10 16:59:35 2010 AlbertoUpdate40m UpgradingUnexpected oscilaltionin the POY11 PDThe measured transimpedance of the latest
POY11 PD matches my model very well up to
100 MHz. But at about ~216MHz I have a resonance
 2010-05-10_POY11_CalibratedOpticalResponse0-500MHz.pngPOX11.png 
  2924   Wed May 12 17:10:16 2010 AlbertoUpdate40m UpgradingRF frequency generation box - step 0I started putting together the components
that are coint to go inside the frequency
generation box. Here's how it looked like:
 DSC_1499_small.JPG 
  2925   Wed May 12 23:31:17 2010 AlbertoUpdate40m Upgrading216 MHz resonance in the POY11 PD killedIt turned out that the resonance at 216
MHz in the 11MHz PD that I showed in the
elog entry 2902
 POX11.png2010-05-12_POY11_CalibratedOpticalResponse0-500MHz.png 
  2926   Thu May 13 05:06:43 2010 ranaUpdate40m Upgrading216 MHz resonance in the POY11 PD killed 
 This idea was tried before
by Dale in the ~1998 generation of PDs. Its
  
  2957   Thu May 20 12:34:46 2010 kiwamuConfiguration40m Upgradingoptical breadboards with legsYesterday Steve and I revived two legs
to mount some optical breadboards outside
of the end table.
 leg1_small.pngleg2_small.png 
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