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ID Date Author Type Categoryup Subject Text Attachments
  4230   Mon Jan 31 07:41:23 2011 AidanUpdateGreen LockingDFD - medm screenI added an MEDM screen for the DFD to the
GREEN screen. It is displayed in the attached
screen shot.
 Screenshot-3.png 
  4232   Mon Jan 31 12:40:38 2011 rana, joeUpdateGreen LockingDFD - medm screenThis is a plot showing the old filters
and the new ones we added this morning.
The new ones have a Cheby for AC
 a.pdf 
  4234   Mon Jan 31 18:25:25 2011 AidanUpdateGreen LockingDFD - results from the new filters (and running with AWG)


   
        
            
 DFD-bandwidth_noise_CLP500_to_300Hz.pdfDFD-bandwidth_noise_CLP500_to_7000kHz.pdf 
  4237   Wed Feb 2 03:27:20 2011 KojiSummaryGreen Locking85MHz Freq dividerThe freq divider was built and installed
in the beat detection path.
Attachment 1: Circuit diagram
 freq_divider.pdfIMG_3816.JPGIMG_3818.JPG 
  4238   Wed Feb 2 09:56:55 2011 KojiSummaryGreen LockingInstalled the freq divider and Rana's PFD- The freq divider and Rana's PFD were
hooked up to the ADCs. (Attachment 1)
(I leave the analog PFD not explained
 freq_divider_installation.pdf110201_freq_divider_output.pdf 
  4239   Wed Feb 2 10:44:26 2011 KojiSummaryGreen LockingFreq fluctuation measured by the freq divider and Rana's analog PFDThe freq fluctuation of the beat note
has been measured with the following condition

    The IR beam only locked
 110201_green_freq_fluctuation.pdf 
  4240   Wed Feb 2 12:55:34 2011 KojiSummaryGreen LockingFreq fluctuation measured by the freq divider and Rana's analog PFDI found that some flakiness of the beat
signals comes from the RF components for
the beat detection.
  
  4248   Fri Feb 4 11:10:27 2011 SureshUpdateGreen LockingVCO PLL Frequency noiseThis measurement pertains to the BL2002
VCO PLL unit.
 
 VCO_calibration.pngVCO_PLL_Servo.pngVCO_Gain.pngVCO_Transfer_Functions.pngVCO_PLL_Freq_Noise.png 
  4259   Tue Feb 8 10:23:02 2011 AidanSummaryGreen LockingDigital Frequency Discriminator - reference 
Here's the reference for the self-reference
frequency detection idea. See Figure 2.
  
  4260   Tue Feb 8 13:26:11 2011 AidanSummaryGreen LockingTemperature dependence of phase change of green on reflection I did a quick back of the envelope
calculation of the expected green phase change
on reflection from the aLIGO ITM.
  
  4261   Tue Feb 8 15:22:13 2011 kiwamuUpdateGreen Lockingnew electronics rack at X end Yesterday
I moved the whole green electronics stuff,
which had been sitting on the floor at the
 DSC_2861_ss.png 
  4267   Thu Feb 10 00:23:25 2011 JenneUpdateGreen LockingGreen TRX DC PD installed on PSLUsing a stray beam that is generated as
the transmitted green beam from the Xarm
goes through the viewport to the PSL table,
  
  4268   Thu Feb 10 05:06:35 2011 kiwamuUpdateGreen Lockingbeat noise : a little bit better, and 1Hz peak from amplitude noise coupling I
repeated the same measurement as that Koji
 Screen_shot_2011-02-10_at_4.01.43.pngScreen_shot_2011-02-10_at_4.52.13.png 
  4278   Sun Feb 13 15:02:23 2011 kiwamuUpdateGreen LockingX arm beam offcentering has been measuredThe amounts
of the X arm's beam off-centering have been
 misposition.png 
  4324   Fri Feb 18 15:05:49 2011 kiwamuUpdateGreen Lockingtransfer function of angle to beat note (length) [Koji and Kiwamu]
 We
 a2l_TF.png 
  4341   Wed Feb 23 04:56:59 2011 kiwamuUpdateGreen Lockingnoise curve updateNew
noise spectra of the green locking have been
updated.
 noise_suprresion.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.
  
  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 
  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 
  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 
  4361   Sat Feb 26 02:33:16 2011 kiwamuUpdateGreen Lockingsidebands on beatnote The  beat_note.png 
  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
  
  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
  
  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 
  
  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 
  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 
  4372   Thu Mar 3 00:12:52 2011 kiwamuUpdateGreen LockingplanTomorrow's tasks
 
- Auto noise budget 
  
  4373   Thu Mar 3 07:25:24 2011 kiwamuUpdateGreen Lockingscrewed up the end PDH box I somehow screwed   
  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 
  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 
  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.
  
  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
  
  4385   Tue Mar 8 15:20:31 2011 kiwamuUpdateGreen Lockingdifferential noise on Mar.8th   differential_noise20110308.png 
  4387   Tue Mar 8 15:33:09 2011 kiwamuSummaryGreen Lockingplan on Mar.8th
  
  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 
  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 
  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 
  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
         
  
  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.

  
  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
  
  4401   Thu Mar 10 16:00:53 2011 Aidan, JoeUpdateGreen LockingIntensity stabilization loop using beatnote DC.Aidan: Joe and I have added a channel that
takes the DC output from the vertex beatnote
PD and sends it, via RFM, to a DAC at the
 P1000313.jpgP1000314.jpgP1000315.jpgGREEN_ISS_LOOP.pdfScreenshot-C1ALS_OVERVIEW.adl.png 
  4403   Thu Mar 10 21:45:34 2011 ranaUpdateGreen LockingIntensity stabilization loop using beatnote DC.Ridiculous
and hacky. Digital stabilization removed
as well as the old "leave a pile of
  
  4411   Fri Mar 18 12:22:04 2011 kiwamuUpdateGreen LockingY arm plan for today Prior
to the works on the Y end setup I propose
to perform the temperature scan business
  
  4413   Fri Mar 18 16:06:30 2011 kiwamuUpdateGreen LockingRe: Y arm plan for todayWe use
Alberto's laser for the Y end Green Locking.
  
  4414   Fri Mar 18 16:31:11 2011 Suresh UpdateGreen LockingRe: Y arm plan for todayThe
reason for using Alberto's laser is that
some amount of work has already gone into
  
  4416   Fri Mar 18 17:55:58 2011 SureshConfigurationGreen LockingWork Plan for Y-end Aux laser installationA rough
time-table and the various tasks are given
below: 
  
  4419   Mon Mar 21 16:49:11 2011 kiwamuSummaryGreen Lockingplan for this week- Plan for this
week
  
  4420   Mon Mar 21 18:34:10 2011 kiwamuUpdateGreen Lockingadded a new ADC channel on 1X9I added a new ADC channel for a DC signal
from the X end green PD.
 aa_board_1X9.jpg 
  4421   Tue Mar 22 00:01:25 2011 kiwamuSummaryGreen Lockingplan for daytime tasksSome
tasks for the daytime tomorrow.
  * Beam profile measurements
  
  4422   Tue Mar 22 00:03:29 2011 BryanConfigurationGreen LockingPSL vs Y arm laser temperature pairing OK. Today we did the same type of
measurement for the Y arm laser as was done
for the X arm laser here: 
 PSL_vs_Y_arm_Temperatures.png 
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