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  4400   Thu Mar 10 14:30:53 2011 ranaUpdateGreen LockingIntensity noise limits the beatnote sensitivityThere are 3 standard techniques to
reduce this effect:
1) Stabilize the end laser by sensing
  
  4399   Thu Mar 10 14:29:05 2011 KojiUpdateGreen LockingIntensity noise limits the beatnote sensitivityWe can modify the freq divider circuit
to make it a comparator.

  
  4398   Thu Mar 10 14:22:58 2011 kiwamuUpdateGreen LockingIntensity noise limits the beatnote sensitivityThe next steps we should do are :
    - to investigate
a cause of the intensity fluctuation
         
  
  4397   Thu Mar 10 14:06:54 2011 kiwamuUpdateGreen LockingIntensity noise limits the beatnote sensitivityWe are limited
by the intensity noise of the X arm transmitted
 diff_noise_Mar8.pngIN_TF_complete.png 
  4396   Thu Mar 10 13:44:56 2011 josephbUpdateCDSAdded digitization noise to the c1spy model for simulated ADCs/DACsTo simulate digitization noise, the easiest
way I found was to use the MathFunction block,
found in the CDS_PARTS model, under simLinkParts. 
  
  4395   Thu Mar 10 01:31:37 2011 KevinUpdateElectronicsAS55 CharacterizationsI measured the transfer function, shot
noise, and dark spectrum of AS55.
From the shot noise measurement,
  
  4394   Thu Mar 10 01:28:47 2011 joe, jamie, rana, chrisSummaryCDSSimSuspension !Today was a banner day for  40mETMY.pngdvsim.pngredpill_bluepill.jpg 
  4393   Wed Mar 9 23:19:04 2011 kiwamuUpdateCDSrebooted c1iooFor
some reason the c1ioo machine suddenly died
just 30 miteus before.
  
  4392   Wed Mar 9 18:17:11 2011 kiwamuUpdateGreen LockingIntensity noise couplingHere
is a new plot for the differential noise
measurement. I plot a noise contribution
 diff_noise.pngIN_TF.png 
  4391   Wed Mar 9 17:29:11 2011 steveSummaryVACsingle O-ring protectionWe have one single O-ring on the 40m vacuum
envelope. It is on the OOC west side, facing
the AP table. This O-ring has to be protected
 so1.jpgP1070458.JPG 
  4390   Wed Mar 9 16:07:42 2011 kiwamuUpdateVIDEOcable session[Koji, Steve, Suresh, Kiwamu]
The following video cables have been
newly laid down :
  
  4389   Wed Mar 9 04:46:13 2011 kiwamuUpdateGreen Lockingmore intensity noise measurement 
Here is a diagram for our intensity
noise coupling measurement.
 intensity_setup.pngIntensityNoise.png 
  4388   Tue Mar 8 16:59:47 2011 josephbUpdateCDSSimulated Plant WorkThe screens for the simplified c1spx model
have been updated.  I re-introduced
the suspension point information into the
  
  4387   Tue Mar 8 15:33:09 2011 kiwamuSummaryGreen Lockingplan on Mar.8th
  
  4386   Tue Mar 8 15:23:16 2011 steveUpdatePEMclean room glovesAnsell
AccuTech
91-300 clean
  
  4385   Tue Mar 8 15:20:31 2011 kiwamuUpdateGreen Lockingdifferential noise on Mar.8th   differential_noise20110308.png 
  4384   Tue Mar 8 14:50:19 2011 kiwamuUpdateCDSnames for filter modules[Joe/Kiwamu]
 
  
  4383   Tue Mar 8 06:29:06 2011 kiwamuUpdateGreen LockingIntensity noise setup[Jenne, Chris, Kiwamu]
 A
photo diode and an AOM driver have been newly
  
  4382   Mon Mar 7 18:20:01 2011 kiwamuSummaryGreen Lockingplans
This
week's goal is to investigate the source
of the differential noise and to lower it.
  
  4381   Mon Mar 7 17:58:14 2011 sureshSummaryGeneralStuff from LLO
Here is the updated list. These lists were
used as packing lists and therefore are organised
 eLIGO_items_from_LLO_for_Caltech_Sheet1.pdf 
  4380   Mon Mar 7 17:22:39 2011 josephbUpdateCDSNew simulated plant work[Joe, Jamie]
We modified the c1scx model to have
a switch to go between simulated and real
  
  4379   Fri Mar 4 18:06:34 2011 kiwamuUpdateGreen Lockingnoise budget : differential noiseHere I explain how I estimate the contribution
from the differential noise shown in the
plot on my last entry (#4376)
 open_loop_TF.pngservos.png 
  4378   Fri Mar 4 13:25:04 2011 ZachUpdateelogrestartedwith script   
  4377   Fri Mar 4 09:47:46 2011 SureshUpdateElectronicsHarmonic distortion calculations for RF distribution box 
Fast work indeed! It would be nice
if we could have the following details filled
  
  4376   Fri Mar 4 03:31:35 2011 kiwamuUpdateGreen LockingA first noise budgetI made a noise budget for the ALS noise
measurement that I did a week ago (see
#4352).
 noise_budget.png 
  4375   Thu Mar 3 20:30:03 2011 ranaSummaryPSLPMC Sweeps @ different input power levels to measure the FinesseIts been well
noted in the past that sweeping the PMC
at high power leads to a distortion of the
  
  4374   Thu Mar 3 18:32:33 2011 Larisa ThorneUpdateElectronicsHarmonic distortion calculations for RF distribution boxFinished calculations for harmonic distortion
at each of the 10 outputs of the RF distribution
box. The diagram can be found on Suresh's
 RFdistribboxcalcs.pdf 
  4373   Thu Mar 3 07:25:24 2011 kiwamuUpdateGreen Lockingscrewed up the end PDH box I somehow screwed   
  4372   Thu Mar 3 00:12:52 2011 kiwamuUpdateGreen LockingplanTomorrow's tasks
 
- Auto noise budget 
  
  4371   Wed Mar 2 22:57:57 2011 sureshSummaryGeneralStuff from LLOHere is a partial list of stuff which is
being packed at LLO to be shipped to CIT. 
The electronics ckt boards are yet to be
 eLIGO_items_from_LLO_for_Caltech.xls 
  4370   Wed Mar 2 22:04:22 2011 KevinUpdateElectronicsPOY Shot Noise MeasurementThe previous measurement for the shot noise
of POY had the dark noise at ~100 nV/rtHz.
I redid the measurement and got 26 nV/rtHz
  
  4369   Wed Mar 2 18:08:43 2011 AidanUpdateGreen LockingGhost beams on greenKiwamu and I noticed that there is a ghost
beam on the green beam going into the ETM.
What we see is some interference fringes
 Ghost_Beam_at_ETM_DCBS.pdf 
  4368   Wed Mar 2 17:19:58 2011 AidanConfigurationGreen LockingMoved PDH PD on end tableAs previously noted, there are multiple
beams coming back from the ETM surface onto
the PDH PD on the end table. They are spread
 P1000223-a.jpgP1000218.jpgP1000224.jpg 
  4367   Wed Mar 2 16:51:53 2011 steveConfigurationGreen Lockingmech shutter in place at the south endI moved old POX shutter from ITMY optical
table to the south end. MEDM POX mechanical
shutter screen is now closing the green beam 
  
  4366   Wed Mar 2 04:01:51 2011 KojiUpdateIOOMC servo improvement[Koji / Rana]
- Since the MC servo had UGF up to
~20kHz and huge servo bump at 50kHz, we needed
 IMG_3904.jpgMC_OLTF.pdf 
  4365   Tue Mar 1 08:42:18 2011 AidanUpdateelogRestarted the elog this morning The elog was dead this morning.
I reanimated it. It is now undead.
 Zombie.gif 
  4364   Mon Feb 28 11:22:40 2011 josephbSummaryGeneralto do list

   
        
            
  
  4363   Sun Feb 27 13:09:56 2011 ranaUpdateGreen Lockingsidebands on beatnoteWhen Koji and I were massaging the MC,
we noticed that the oscillations were at
48.5 kHz. They were pretty huge and are probably
  
  4362   Sun Feb 27 09:43:59 2011 AidanUpdateGreen Lockingsidebands on beatnoteCan we set up a fiber-PD on the end table
to look at the beat between the "end
laser IR beam" and the "PSL IR
  
  4361   Sat Feb 26 02:33:16 2011 kiwamuUpdateGreen Lockingsidebands on beatnote The  beat_note.png 
  4360   Sat Feb 26 00:25:38 2011 KojiUpdateIOOMC servo improvement[Rana / Koji]
The MC servo loop has been investigated
as the MC servo was not an ideal state.
 fss_servo.pngmc_servo.png 
  4359   Fri Feb 25 14:50:16 2011 KojiSummaryGeneralto do list- Put priority on the list
- Put names on the items
- Where is the CDS TO DO ==> Joe
  
  4358   Fri Feb 25 14:35:06 2011 Larisa ThorneUpdateElectronicsTotal harmonic distortion results for +7dBm mixer This experiment deals with measuring
the total harmonic distortion (THD) contribution
 THDcircuit.jpgPhoto_on_2011-01-17_at_12.25.pngTHDwithoutamp.pdf 
  4357   Fri Feb 25 13:28:14 2011 kiwamuSummaryGeneralto do list Because it maybe useful to share
this kind of information among us, I just
  
  4356   Fri Feb 25 10:11:56 2011 steveUpdateSAFETYhow not toThe beam of IR for doubling  is clipping
on bnc cable to green beam transmitted pd.
 Presentation1.jpg 
  4355   Fri Feb 25 01:48:54 2011 valeraUpdateASCmc auto alignment status I made several scripts to handle
the mcass configuration and sensing measurements:
- The scripts and data are in the 
 mcditherlines.pdfmcdecenter.pdfmcmirror.pdf 
  4354   Thu Feb 24 21:46:30 2011 kiwamuUpdateGreen Lockinginstalled a summing boxIn
this past weekend I replaced a summing amplifier
for the end green PDH locking by a home-made
 summing_box.pngtransfer_func.png 
  4353   Thu Feb 24 19:59:25 2011 kiwamuUpdateGreen Lockingwhitening filter for ALSI forgot to mention about the whitening
filter for the ALS digital control system.
As usual I used a whitening filter
 ACDC.png 
  4352   Thu Feb 24 18:21:24 2011 kiwamuUpdateGreen Lockingin-loop and out-of-loop measurementsTwo different measurement have been
performed for a test of the green locking
last night.
 green_lock_setup.pngmeasurement1.pngTRX_REFL11.pngmeasurement2.png 
  4351   Thu Feb 24 17:42:00 2011 AidanUpdateGreen Locking15% of end laser sideband power transmitted through cavityI did a quick calculation to determine
the amount of sideband transmission through
the FP cavity.
  
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