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ID Date Author Type Category Subject
4824   Wed Jun 15 15:18:01 2011 kiwamuUpdateGeneralWednesday cleaning

[Jenne / Kiwamu]

We spent approximately an hour for the weekly Wednesday cleaning.

This time we moved onto an area where a desk and optics shelf reside along the Y arm.

We will continue cleaning up there in the next time too.

4823   Wed Jun 15 12:16:37 2011 JamieUpdateLockingMICH noise budget?

 Quote If you tilt your head sideways, you will notice that in this plot (totally uncalibrated, as yet), the BLACK trace, which is my white-light measurement of the AS55 shot noise is above the AS55Q noise when the Michelson is locked (true only at low frequency).  You will also notice that the same appears to be true for the Whitening Filter + Antialiasing Filter + ADC noise (GRAY trace).  Since Black, Gray, Pink and Green should all have the same calibration factor (a constant), calibrating the plot will not change this.  Brown and Blue are the MICH_OUT (aka MICH_CTRL) for dark and bright fringes, respectively.

Hey, Jenne.  I think there are a couple of things.  First, you're missing a PD dark noise measurement, which would be useful to see.

But I think the main issue is that it sounds like all of your closed loop measurements are done with the in-loop PD.  This means that everything will be suppressed by the loop gain, which will make things look like they have a noise lower than the actual noise floor.

4822   Wed Jun 15 02:20:00 2011 JenneUpdateLockingMICH noise budget?

I would like to announce my confusion with regard to the MICH noise budget, in hopes that someone else has some inspiration

If you tilt your head sideways, you will notice that in this plot (totally uncalibrated, as yet), the BLACK trace, which is my white-light measurement of the AS55 shot noise is above the AS55Q noise when the Michelson is locked (true only at low frequency).  You will also notice that the same appears to be true for the Whitening Filter + Antialiasing Filter + ADC noise (GRAY trace).  Since Black, Gray, Pink and Green should all have the same calibration factor (a constant), calibrating the plot will not change this.  Brown and Blue are the MICH_OUT (aka MICH_CTRL) for dark and bright fringes, respectively.

I measure 58mV at the DC out of the AS55 PD when the Michelson is locked on the bright fringe.  This (assuming DC transimpedance of 50ohms) gives 1.16mA of DC photo current.

So.  What is going on here?  Am I totally confused??

In other news, assuming (which I'm not 100% confident about right now) that these traces are vaguely correct, the Michelson is limited by shot noise above ~20Hz.  This is...good?  We want to be shot noise limited.  Do we want to be limited at such a low frequency?

(Also, yes I can calibrate the plot to m/rtHz, but no, I won't tonight because something is funny with my calibration for the free running noise and I'll fix it tomorrow.)

4821   Wed Jun 15 01:30:38 2011 JamieSummaryLSCSchnupp asymmetry measurement

# Measurement of Schnupp asymmetry

This was done by measuring the relative phase between the sidebands reflected from the two arms while the arm cavities are locked.

The Schnupp asymmetry is measured to be:   Lsa = 3.64 ± 0.32 cm

## Description:

As a phase reference we use the zero crossing of the response function for the out-of-phase control signal for the single arm cavity lock [0]. The difference in the RD rotation phase of the response zero crossings indicates the phase difference in the sideband signals reflected from the arms. Assuming the asymmetry is less than half the RF modulation wavelength [1], the asymmetry is given by the following formula:

       \Delta \phi   c   1
L_sa = ----------- ----- -
360     f_RSB 2


We use a LSC digital lock-in to measure the response of the arm cavity at a single-frequency drive of it's end mirror.

[0] The locations of the zero crossings in the out-of-phase components of the response can be determined to higher precision than the maxima of the in-phase components.

[1] fRSB = 55 MHz,     c/fRSB/2 = 2.725 m

## Procedure:

1. Lock/tune the Y arm only.
• We use AS55_I to lock the arms.
2. Engage the LSC lock-in.
3. Tune the lock-in parameters:
4. lock-in freq: 103.1313 Hz
I/Q filters:  0.1 Hz low-pass
phase:        0 degrees

5. Set as input to the lock-in the out-of-phase quadrature from the control RFPD.  In this case AS55_Q->LOCKIN.
6. Drive the arm cavity end mirror by setting the LOCKIN->Y_arm element in the control matrix.
7. Note the "RD Rotation" phase between the demodulated signals from the control PD (AS55)
8. For some reasonable distribution of phases around the nominal "RD Rotation" value, measure the amplitude of the lock-in I output.
• Assuming the Q output is nearly zero, it can be neglected.  In this case the Q amplitude was more than a factor of 10 less than the I amplitude.
• Here we take 5 measurements, each separated by one over the measurement bandwidth (as determined by the lock-in low pass filter), in this case 10 seconds.  The figure above plots the mean of these measurements, and the error bars indicate the standard deviation.

The data and python data-taking and plotting scripts are attached.

## Error Analysis:

To to determine the parameters of the response (which we know to be linear) we use a weighted linear least-squares fit to the data:

y = b X

where:

X0j = 1
X1j = xj              # the measurement points
y = yi                 # the response
b = (b0, b1)     # line parameters

The weighting is given by the inverse of the measurement covariance matrix. Since we assume the measurements are independent, the matrix is diagonal and Wii = 1/\sigmai2 The
estimated parameter values are given by:

\beta  =  ( XT W X )-1 XT W y  =  ( X'T X' )-1 X'T y'

where X' = w X, y' = w y and wii = \sqrt{Wii}.

The X' and y' are calculated from the data and passed into the lstsq routine. The output is \beta.

The error on the parameters is described by the covariance matrix M\beta:

M\beta = ( XT W X)-1 = ( X'T X')-1

with correlation coefficients \rhoij = M\betaij / \sigmai / \sigmaj.

The x-axis crossing is then given by:

X(Y=0) = - \beta1 / \beta0

## References:

Attachment 2: arm_phase.py
#!/usr/bin/env python

import sys
import os
import subprocess
import time
import pickle
from numpy import *
import nds
import matplotlib

... 229 more lines ...
Attachment 3: plot.py
#!/usr/bin/env python

import pickle
from numpy import *
import matplotlib
#matplotlib.use('AGG')
from matplotlib.pyplot import *

##################################################


... 137 more lines ...
Attachment 4: schnupp_ETMX.pik
(dp0
S'I'
p1
(dp2
cnumpy.core.multiarray
scalar
p3
(cnumpy
dtype
p4

... 341 more lines ...
Attachment 5: schnupp_ETMY.pik
(dp0
S'I'
p1
(dp2
cnumpy.core.multiarray
scalar
p3
(cnumpy
dtype
p4

... 341 more lines ...
4820   Wed Jun 15 00:50:11 2011 KojiHowToComputer Scripts / ProgramsKissel Button Generator

Now the Kissel-button generator takes the command line arguments and options.
The script is fully documented by the usage message of the script itself.
It still needs the external supporting files "MATRIX*.adl_parts".

Now the LSC screen has these buttons for the input and output matrices.
The command lines to generate those buttons are listed at the end of this entry as the examples.

>pwd /opt/rtcds/caltech/c1/medm/c1lsc_tst/master/KisselButtonGenerator 

>./generate_KisselButton.py -h usage: generate_KisselButton.py [options]  end_row end_column matrix_ch_name This generates an MEDM screen of a button with the style designed by Jeff Kissel for his ISI screens. This button has a display of a matrix elements. If the matrix element is non-zero it glows in green. Otherwise its color is dark. Usually the button created by this script is to be copy-pasted to other screens. Three arguments have to be given:   end_row         the number of the row at the end   end_column      the number of the column at the end   matrix_ch_name  the channel name of the matrix to be monitored                   e.g. give C1:LSC-OUTPUT_MTRX for C1:LSC-OUTPUT_MTRX_1_1, ... There are options prepared in order to control the parameters of the button. example: generate_KisselButton.py 6 6 C1:LSC-OUTPUT_MTRX       6x6 matrix for C1:LSC-OUTPUT_MTRX options:   -h, --help          show this help message and exit   --sr=START_ROW      specify the starting row number for the button array.                       [default: 1]   --sc=START_COLUMN   specify the starting column number for the button array.                       [default: 1]   --bw=BUTTON_WIDTH   specify the pixel width of the small button. [default:                       8]   --bh=BUTTON_HEIGHT  specify the pixel height of the small button. [default:                       8]   --dl=DISPLAY_LABEL  specify the button label. [default: channel name]   --sn=SCREEN_NAME    specify the file name of the screen opened when one                       click the button. The relative or absolute path can be                       included. [default: a name guessed from the channel                       name. e.g. C1LSC_OUTPUT_MTRX.adl for C1:LSC-OUTPUT_MTRX] 

>./generate_KisselButton.py --bw=3 --bh=4 --dl="RFPD InMTRX" 16 8 C1:LSC-PD_DOF_MTRX > rfpd_mtrx.adl >./generate_KisselButton.py --sc=21 --bw=6 --bh=4 --dl="DCPD InMTRX" 27 8 C1:LSC-PD_DOF_MTRX > dcpd_mtrx.adl >./generate_KisselButton.py --bw=4 --bh=4 --dl="Trig MTRX" 11 8 C1:LSC-TRIG_MTRX > trig_mtrx.adl >./generate_KisselButton.py --bw=4 --bh=4 --dl="Out MTRX" 9 10 C1:LSC-OUTPUT_MTRX > output_mtrx.adl

4819   Wed Jun 15 00:49:34 2011 SureshUpdateIOOWFS2 has been fixed.

The WFS2 sensor head had a damaged Quadrant PIN diode (YAG-444-4A).  This has been replaced by a   YAG-444-4AH  which has a responsivity of 0.5 A/W.

The responsivity of each quadrant was measured at normal incidence.  A diagram of the set up with the relevant power levels is attached.  The precision of these measurement is about 5% .  Largely because the power levels measured are sensitive to the position of the laser beam on the power meter sensor head (Ophir with ND filter mask taken off).  Putting the mask back on did not solve this problem.

The incident power was 0.491mW  of which about 0.026mW was reflected from the face of the QPD.  The beam was repositioned on the QPD to measure the response of each quadrant.  In each case the beam was positioned to obtain maximum DC output voltage from the relevant quadrant.  A small amount of spill over was seen in the other quadrants.  The measurements are given below

 Position 1 Position 2 Position 3 Position 4 Dark Q1 244 6.7 5.4 6.9 4 Q2 5.9 238 8.4 5 5 Q3 9 6.6 236 7.3 6 Q4 7.5 7 7 252 7

To measure these DC outputs of from the sensor-head a breakout board for the 25-pin D-type connector was used as in the previous measurements.  The results are given below

 DC out (mV) Responsivity A/W Quantum Efficiency (%) Q1 238 0.52 0.60 Q2 233 0.50 0.59 Q3 230 0.50 0.58 Q4 244 0.53 0.61

The measured responsivity agrees with the specification from the manufacturer.  It is to be noted that the previous QPD is reported to have a slightly smaller responsivity 0.4 A/W at 1064 nm.  The data sheet is attached.

Since the new QPD may have a slightly different capacitance the RF transfer function of the WFS2 needs to be examined to verify the location of the resonances.

Quote:

[Larisa and Jenne]

A few weeks ago (on the 28th of January) I had tried to measure the quantum efficiency of one quadrant of the WFS as a function of angle.  However, Rana pointed out that I was a spaz, and had forgotten to put a lens in front of the laser.  Why I forgot when doing the measurement as a function of angle, but I had remembered while doing it at normal incidence for all of the quadrants, who knows?

Anyhow, Larisa measured the quantum efficiency today.  She used WFS2, quadrant 1 (totally oil-free), since that was easier than WFS1.  She also used the Jenne Laser (with a lens), since it's more stable and less crappy than the CrystaLasers.  We put a 50 Ohm terminator on the RF input of the Jenne Laser, since we weren't doing a swept sine measurement.  Again, the Ophir power meter was used to measure the power incident on the diode, and the reflected power, and the difference between them was used as the power absorbed by the diode for the quantum efficiency measurement.  A voltmeter was used to measure the output of the diode, and then converted to current as in the quote below.

Still on the to-do list:  Replace the WFS2 diode.  See if we have one around, otherwise order one.  Align beams onto WFS so we can turn on the servo.

QE = (h*c)/(lambda*e) * (I/P)

Where I = (Volts from Pin1 to GND)/2 /500ohms
P = Power from laser - power reflected from diode.
h, c, e are the natural constants, and lambda is 1064nm.
Also, I/P = Responsivity



Larissa is going to put her data and plots into the elog shortly....

Attachment 2: SensorsBrochure-p12.pdf
4818   Tue Jun 14 18:12:34 2011 Jamie, KiwamuUpdateLSCLSC seems to be fully recovered

We are now locking the arms reliably, with reasonable transmitted power.  We zeroed the LSC offsets with script, since they were apparently not being reset with either the overall burt restore or the arm restore scripts.

We have lost a bit of power through the mode cleaner.  However, we have opted not to tweak it up just yet, so that we don't have to realign to the arms.

4817   Tue Jun 14 16:38:31 2011 JamieUpdatePSLTweaked input pointing to PMC

The PMC trans power was a little low (0.77V or so).  I tweaked up the input pointing and now we're getting about 0.875V transmitted.

4816   Tue Jun 14 12:23:44 2011 Jamie, JoeUpdateCDSWE ARE ALL GREEN! LSC back up and running in new configuration.

After moving the c1lsc computer to 1X4, then connecting c1lsc to it's IO chassis in 1Y3 by a fiber PCIe extension cable, everything is back up and running and the status screen is all green.  c1lsc is now directly connected to c1sus via a short copper Dolphin cable.

After lunch we will do some more extensive testing of the system to make sure everything is working as expected.

4815   Tue Jun 14 09:25:17 2011 JamieUpdateCDSDolphin fiber tested with c1sus, still bad

The bad Dolphin was still bad when tested with a connection between c1sus and the Dolphin swtich.

I'm headed over to Downs to see if we can resolve the issue with the PCIe extension fiber.

4814   Tue Jun 14 09:24:36 2011 steveConfigurationPhotosSUS binary IO chassis 2 and 3 moved from 1X5 to 1X4

 Quote: While preping 1X4 for installation of c1lsc, we removed some old VME crates that were no longer in use.  This freed up lots of space in 1X4.  We then moved the SUS binary IO chassis 2 and 3, which plug into the 1X4 cross-connect, from 1X5 into the newly freed space in 1X4.  This makes the cable run from these modules to the cross connect much cleaner.

Are we keeping these?

Attachment 1: P1070891.JPG
Attachment 2: P1070893.JPG
4813   Tue Jun 14 03:15:29 2011 KojiHowToComputer Scripts / ProgramsKissel Button Generator

I have made a python script to generate the button designed by Jeff Kissel for his ISI screen.

It is currently located at the following location:
/cvs/cds/rtcds/caltech/c1/medm/c1lsc_tst/master/KisselButtonGenerator/generate_KisselButton.py but should be relocated to somewhere appropriate.
It also uses fragmented medm files named "MATRIX*.adl_parts".

# Jamie, could you suggest the right place?

The parameters are assigned at the beggining of the script.
This script print the result to stdout. So you need to redirect the output into a file.
e.g.

> ./generate_KisselButton.py >tmp.adl 

The script should be modified such that it accepts the command line options.
It needs more python learning for me.

# Number of the column mat_h = 20; # Number of the row mat_v = 10; # horizontal pixel size of the rectangular display for each matrix element button_width = 8; # vertical pixel size of the rectangular display for each matrix element button_height = 8; replace_dict = { # Title     '${DISPLAY_LABEL}':'ITMX_INMATRIX', # Path of the MEDM file to be open by clicking the button '${DISPLAY_NAME}':'/cvs/cds/rtcds/caltech/c1/medm/c1sus/master/C1SUS_ITMX_INMATRI X_MASTER.adl', # The channel name of the matrix element # ($V and$H are replaced to the numbers i.e. "_3_4")     '${MATRIX_CHAN}':'C1:SUS-ITMX_INMATRIX_$V_H' }; Attachment 1: kissel_button.png 4812 Mon Jun 13 19:26:42 2011 Jamie, JoeConfigurationCDSSUS binary IO chassis 2 and 3 moved from 1X5 to 1X4 While preping 1X4 for installation of c1lsc, we removed some old VME crates that were no longer in use. This freed up lots of space in 1X4. We then moved the SUS binary IO chassis 2 and 3, which plug into the 1X4 cross-connect, from 1X5 into the newly freed space in 1X4. This makes the cable run from these modules to the cross connect much cleaner. 4811 Mon Jun 13 18:40:08 2011 Jamie, JoeUpdateCDSSnags in the repair of LSC CDS We've run into a problem with our attempts to get the LCS control back up and running. As reported previously, the Dolphin fiber connection between c1lsc and c1sus appears to be dead. Since we have no replacement fiber, the solution was to move the c1lsc machine in to the 1X4 rack, which would allow us to use one of the many available short Dolphin cables, and then use a long fiber PCIe extension cable to connect c1lsc to it's IO chassis. However, the long PCIe extension cable we got from Downs does not appear to be working with our setup. We tested the cable with c1sus, and it does not seem to work. We've run out of options today. Tomorrow we're going to head back to Downs to see if we can find a cable that at least works with the test-stand setup they have there. 4810 Mon Jun 13 16:27:10 2011 JenneUpdateElectronicsSeismometer Box Update/graphs  Quote from elog 4807: The noise graphs relating total noise of the Seismometer circuit (GURALP stuff) to the LIGO seismic noise curve have been completed started. What Larisa meant to post (I'm sure) is something more like this (sorry it's a little squished...I put too many words in the legend): I've only included the 2 noise contributions from the LISO model that seem to dominate the sum noise. The plot gets a little crazy if you include all of the non-important sources. So, what's the point?? First, the new box design doesn't have any crazy-special op-amps in it, so the noise of the new box is probably comparable to the old box. So, if that's true, the old box may not have been limiting the differential seismic noise. This definitely needs to be checked out. I'll make a quickie LISO model of the old Guralp breakout box, to see what its noise actually looks like, according to LISO. If it wasn't ever the breakout box that was limiting us, what the heck was it?? Second, the current box design seems to be better than the Guralp Spec sheet noise by ~a factor of 10. It would be nice if that number were more like a factor of 100. Or at least 30. So some work needs to be done to find a lower-noise op amp for the voltage buffer (the first op amp in the circuit). Next steps: Since Larisa is now starting her SURF project with Tara and Mingyuan, I'll look into improving the design of this box by a factor of 3 or 10. Then I'll need to make a mock-up of it, and test it out. If successful, then I'll draw it up in Altium and have it made. Recall that there should be 2 outputs per seismometer channel, one with high gain, one with low gain. Then 3 seismometer channels per seismometer (X, Y, Z), and perhaps multiple seismometer inputs per box. So lots and lots of stuff all in the same box. It's going to be pretty cool. 4809 Mon Jun 13 15:33:55 2011 Jamie, JoeUpdateCDSDolphin fiber between 1Y3 and 1X4 appears to be dead The fiber that connects the Dolphin card in the c1lsc machine (in the 1Y3 rack) to the Dolphin switch in the 1X4 rack appears to have died spontaneously this morning. This was indicated by loss of Dolphin communication between c1lsc and c1sus. We definitively tracked it down to the fiber by moving the c1lsc machine over to 1X4 and testing the connection with a short cable. This worked fine. Moving it back to using the fiber again failed. Unfortunately, we have no replaced Dolphin fiber. As a work around, we are stealing a long computer->IO chassis cable from Downs and moving the c1lsc machine to 1X4. This is will be a permanent reconfiguration. The original plan was to have the c1lsc machine also live in 1X4. The new setup will put the computer farther from the RF electronics, and more closely mimic the configuration at the sites, both of which are good things. 4808 Mon Jun 13 12:34:21 2011 Jamie, KojiUpdateLSCUpdated LSC model installed After a couple of hickups, I was able to compile and install Koji's rework of the LSC model. The main changes are that the model now use an RF_PD library part, and the channel names were tweaked to be more in line with what we expect. I found a couple of small bugs in the model that were preventing it from compiling. Those were fixed and it compiled with no further problems. There was also some rearrangement of signal inputs to the PD_DOF matrix. The matrix screen was updated to reflect the proper inputs. However, this also meant that the burt restore scripts for the IFO configurations were setting the wrong elements in the matrix. I fixed the settings for X and Y arm locking, and updated the burt snapshots using the burt/c1ifoconfigure/C1save{X,Y}arm scripts. NOTE: burt settings will need to be updated for the MICH, PRM, DRM, and FULL IFO configurations as well. During the build/install process, Joe and I also found a bug in the feCodeGen that was causing the filter screens to be created with the wrong names. Joe sent out a patch that will hopefully be merged soon. Building the model with Joe's patch fixed the screen names, so the screens are currently named correctly. 4807 Fri Jun 10 20:23:56 2011 Larisa ThorneUpdateElectronicsSeismometer Box Update/graphs (continuation of this) The noise graphs relating total noise of the Seismometer circuit (GURALP stuff) to the LIGO seismic noise curve have been completed started. I apparently harbor hate towards Matlab (you may have notice I do everything in Mathematica)....I will try to change my ways DX Attachment 1: SeisNoiseGraphs.jpg 4806 Fri Jun 10 18:49:40 2011 kiwamuUpdateIOOIntensity Noise after the MC Last night the relative intensity noise (RIN) of the beam after MC was measured. It looks like the RIN is dominated by the motion of the MC mirrors, possibly the angular motions because we don't have any angular stabilization servos. Suresh will estimate the contribution from the MC mirrors' angular motion to the RIN in order to see if this plot makes sense. (RIN) The spectrum below 30 Hz seems to be dominated by the motion of the MC suspensions because it very resembles the spectra of those. Above 30 Hz the spectrum becomes somehow flat, which I don't know why at the moment. A rough estimation of the shot noise gave me a level of 10^{-9} RIN/sqrtHz, which is way below the measured spectrum. (Setup) All of the suspended mirrors were intentionally misaligned except for the MC mirrors and PRM to avoid interference from the other optics. In this setup it allows us to measure the intensity noise of the laser which is transmitted from MC. The beam transmitted from MC is reflected by PRM and finally enters into the REFL11 RFPD. The DC signal from the RFPD was acquired at C1:LSC-REFL_DC_DQ as the laser intensity. As well as the RIN measurement I took a spectrum when the beam is blocked by a mechanical shutter on the PSL table. This data contains the dark noise from REFL11 and circuit noise from the whitening, AA board and ADC. It is drawn in black in the plot. The cut off at 15 Hz is possibly due to the digital unwhitening (two poles at 15 Hz and two zeros at 150 Hz) filter to correct the analog whitening filter. 4805 Fri Jun 10 14:50:37 2011 KojiUpdateLSCNew LSC code installed [Koji Jamie] The new c1lsc code has been installed. The LSC screens have also been updated (except for ASS screen). The major changes are: 1. Naming of the RFPD channels. Now the PD signals were named like: REFL11_I_IN1, REFL11_I_IN2, REFL11_I_OUT .... instead of REFL11I_blah 2. NREFL11, etc has been removed. We now have the official error signals named like REFL11_I_ERR We can't use the name "REFL11_I" for the error signal as this name is occupied by the name of the filter module. 4804 Fri Jun 10 12:04:57 2011 JenneUpdateRF SystemBad RF connections!! I am in the process of calibrating AS55's shot noise, and I noticed that the AS55 PD input to the demod board was only finger-tight. I then checked all of the other SMA connections in the set of RF PD demod boards, and found several more that were loose, including all of the REFL55 connections. This is no good!!!! RF connections need to be tightened! I went through and tightened all of the offending connections with my personal Snap-on SMA wrench. 4803 Fri Jun 10 12:02:10 2011 ranaUpdateCDSSecond trends only go back 12 days  Quote: While answering a quick question by Kiwamu, I noticed we only had second trends going back to 99050000 GPS time, May 27th 2011. Trends (I thought) were intended to be kept forever, and certainly longer than full data, which currently goes back several months. Jamie will need to look into this. Our concept is to keep second trends for 1-2 months and minute trends forever. The scheme that Alan had worked out many years ago had it such that we could look back to 1998 and that the minute trends would be backed up somehow. If its not working, we need to get Alan's help to recover the previous configuration. 4802 Thu Jun 9 20:10:38 2011 kiwamuUpdateSUSETMY whitening filter : all off I checked the state of the whitening filters for the ETMY shadow sensors. Result : They've been OFF (i.e. flat response). (measurement and setup) I measured the transfer functions of the whitening board (D000210) by looking at the signal before and after the whitening stage. The whitening board handles five signals; UL, UR, LR, LL and SD, and there are five single-pin lemo outputs for each signal on the front panel. A good thing on those lemo monitors is that their signals are monitored before the whitening stages. Rana suggested me to use these signals for the denominator of the transfer functions and consider the sensor signals as excitation signals. So I plugged those signals into extra ADC channels via an AA-board and measured the transfer functions. In the measurement the coherence above 4 Hz was quite small while the suspension was freely swinging. Therefore I had to excite the ETMY suspension by putting random noise in a frequency band from 5 Hz to 35 Hz to obtain better coherence. (results) The response is flat over frequency range from ~ 0.2 Hz to ~40 Hz, see the plot below. According to the spectrum of each signal the measurements above 10 Hz are just disturbed by the ADC noise. If the whitening filters are ON, a pole and zero are expected to appear at 30 Hz and 3 Hz respectively according to the schematic, but no such features. 4801 Thu Jun 9 18:25:22 2011 kiwamuHowToCDSlook back a channel which doesn' exist any more For some purposes I looked back the data of some channels which don't exist any more. Here I explain how to do it. If this method is not listed on the wiki, I will put this instruction on a wiki page. (How to) (1) Edit an "ini" file which is not associated to the real-time control (e.g. IOP_SLOW.ini) (2) In the file, write a channel name which you are interested in. The channel name should be bracketed like the other existing channels. example: [C1:LSC-REFL11_I_OUT_DAQ] (3) Define the data rate. If you want to look at the full data, write datarate = 2048 just blow each channel name. Or if you want to look at only the trends, don't write anything. (4) Save the ini file and restart fb. If necessary hit "DAQ Reload" button on a C1:AAA_GDS_TP.adl screen to make the indicators green. (5) Now you should be able to look at the data for example by dataviewer. (6) After you finish the job, don't forget to clean up the sentences that you put in the ini file because it will always show up on the channel list on dtt and is just confusing. Also don't forget to restart fb to reflect the change. 4800 Thu Jun 9 16:18:03 2011 josephbUpdateCDSSecond trends only go back 12 days While answering a quick question by Kiwamu, I noticed we only had second trends going back to 99050000 GPS time, May 27th 2011. Trends (I thought) were intended to be kept forever, and certainly longer than full data, which currently goes back several months. Jamie will need to look into this. 4799 Thu Jun 9 12:21:07 2011 kiwamuUpdatePSLRe : PMC needs help Nulling the slow actuation offset fixed the issue. Now PMC is back to normal. The reflected beam on the CCD was quite symmetric (it looked very TEM00 mode !) for some reasons, I somehow suspected the mode matching to PMC. One possibility I thought of was the laser temperature because it could change the laser spatial mode. So I looked at the slow actuation offset on the FSS screen and found it was at -4.0 which sounds somewhat big. Then I zeroed the offset by the slider and relocked PMC. Then the spatial pattern of the reflected beam became usual (i.e. junk light looking) and the transmitted light wet up to 0.83 which is normal.  Quote from #4798 The PMC is losing power. 4798 Thu Jun 9 10:38:30 2011 steveUpdatePSLPMC needs help The PMC is losing power. Attachment 1: pmcnothp.jpg 4797 Wed Jun 8 23:17:25 2011 kiwamuUpdateLSCDRMI output matrix diagonalization Approximately two weeks ago I diagonalized the LSC output matrix for the DRMI locking. Since actuation on the position of BS changes not only MICH but also PRC and SRC, we needed to diagonalize the output matrix. - What I did : (1) The DRMI was locked. At this point PRC, MICH and SRC was controlled by PRM, BS and SRC actuators respectively. (2) I injected excitation signal on C1:LSC-MICH_EXC by awg. The excitation was at about 200 Hz, which is above the UGF of all the LSC loops. At this point the excitation only shakes the position of BS. (3) I looked at spectra of REFL11_I, AS55_Q, AS55_I, that were used to sense PRC, MICH and SRC respectively. At the beginning I was able to see the peak due to the excitation in those spectra. This means BS shakes the other DOFs (i.e. PRC and SRC) as well as MICH. (4) To minimize the coupling from MICH to PRC (or SRC), I tuned a number on an element of the output matrix, which transfers the signal from MICH to PRM (or SRM). This business was done by looking at the peak on REFL11_I (or AS55_I) and minimizing it. Since this technique was too naive the tuning was done only in second decimal place. 4796 Wed Jun 8 22:48:09 2011 ranaUpdateCamerasITM camera lenses changed I focused these lenses so that we could get a clean image of the mirrors and the OSEMs. Our goal is to have an image where the optic diameter almost fills the entire monitor. We want the focus to be adjusted for the YAG beam (which is almost the same as focusing for the OSEMs). This will NOT produce a nice image of the cage using visible light, but that is just fine. When Justin Garofoli was here he found a nice lens combo that did the job, so if anyone can find his old email or elog, lets just go back to that. For now, we do not need a camera/lens system to focus very tightly on the center of the optic. 4795 Wed Jun 8 16:41:48 2011 valeraUpdateASSX and Y arm dither alignment status The current status of the dither alignment system: - Both Xarm and Yarm alignment are working. The scripts are: scripts/autoDither/alignX(Y). Each script sets up the respective arm, turns on the dither lines and servos for 66 sec, offloads the control signals to TM alignment biases and PZT sliders in case of Yarm, and to TM and BS alignment biases in case of Xarm, and finally turns off and clears the servo filters and turns off the dither lines. - Jammie witnessed the final tests of both scripts - both X and Y arm power went up from 0.6-0.7 to close to 1 and the AS beam became symmetric. Also Jammie wanted me to leave the ETMY oplev in its current non-nominal but more stable state i.e. the oplev signals go to the ADC from the D010033 card not the D020432 one. The scripts can now run from the CONFIGURE medm screen. - Both arms use signals derived from modulating ITM and ETM in pitch and yaw dofs and demodulating the arm power (TRX or TRY) and the cavity length signal (AS55I). The Yarm actuation has 8 dofs - pitch and yaw of the ITM, ETM, and two input beam PZTs so all the sensed dofs are controlled. The Xarm actuation has only 6 dofs - pitch and yaw of the ITM, ETM, and BS. The Xarm servo is set up to servo the beam position on the ETMX and the relative alignment of the cavity and the input beam. The ITMX spot position is unconstrained and provides the null test. The residual displacement on the ITMX is 0.2-0.3 mm in yaw and 0.9-1.0 mm in pitch. The I phases of the beam centering lockins, which are also the error points of corresponding DOF filters, are calibrated in mm by unbalancing the TM coils by known amount. The attached snap shot of the medm screen now has both X and Y arm calibrated beam spot positions and uncalibrated input beam indicators. The input beam angle and position signals can/should be calibrated by tapping the signals digitally and applying the proper matrix transformation - this will require the model change. - Currently there is no lock loss catching in the model. We should add a trigger on arm power (or an equivalent mechanism) to turn off the inputs to prevent the spurious inputs. Attachment 1: BeamPositionIndicators.png 4794 Tue Jun 7 16:11:09 2011 steveUpdateCamerasITM camera lenses changed Computar 75-12.5 zooms were installed for closer look at the resonant spots. Their alignment and focus needs more loving adjustment. Atm 1, ITMX ( it was 10-40 mm Tamron before ) Atm 2, ITMY ( it was 12mm wide angle showing the towers before ) Attachment 1: P1070865.JPG Attachment 2: P1070860.JPG 4793 Tue Jun 7 11:39:27 2011 JamieUpdateSUSNo binary output module in ETMY  Quote: 1) The FM1 files in the XXSEN modules should switch the analog shadow sensor whitening. I found today that, at least on ETMY and ETMX, they do nothing. This needs to be fixed before we can use the suspensions. Joe discovered today that ETMY in fact has no binary output module at all, so there is actually no digital control of the whitening filters at ETMY. We suspect that the ETMY binary output module was maybe harvested to put in the LSC rack, but we're not sure. We found a spare binary output adapter pcb, which I will try to assemble into a module to install in ETMY. This does not explain what's going on with ETMX, though. ETMX has a binary output module, that appears to be properly hooked up. I'll try to debug what's going on there as well. In the mean time, I've removed the ETMX binary output module to use as a reference for putting together another identical module for ETMY. 4792 Mon Jun 6 23:56:16 2011 rana, valeraConfigurationSUSETMX/ETMY OSEM whitening We measured the OSEM PD whitening transfer function of the ETMX OSEM UL whitening stage (D000210) by comparing the input signal to the whitening amplifier (single pin LEMO monitor) to the output signal - both were piped into the DAQ. The transfer function was close to constant 0 dB/180 deg independent of the whitening switch selection (FM1 filter engaged/disengaged) up to ~20 Hz where we run out of coherence. All other ETMX and ETMY spectra at the input of the digital whitening compensation don't change when the whitening is switched on/off so by induction we conclude that all the ETMX/ETMY OSEM PD hardware whitening filters are not on. 4791 Mon Jun 6 22:41:22 2011 ranaUpdateSUSSwitching problem in SUS models Some weeks ago, Joe, Jamie, and I reworked the ETMY controls. Today we found that the model rebuilds and BURT restores have conspired to put the SUS damping into a bad state. 1) The FM1 files in the XXSEN modules should switch the analog shadow sensor whitening. I found today that, at least on ETMY and ETMX, they do nothing. This needs to be fixed before we can use the suspensions. 2) I found all of the 3:30 and cts2um buttons OFF AGAIN. There's something certainly wrong with the way the models are being built or BURTed. All of our suspension tuning work is being lost as a consequence. We (Joe and Jamie) need to learn to use CONLOG and check that the system is not in a nonsense state after rebuilds. Just because the monitors have lights and the MEDM values are fluctuating doesn't mean that "ITS WORKING". As a rule, when someone says "it seems to work", that basically means that they have no idea if anything is working. 3) We need a way to test that the CDS system is working... Attachment 1: a.pdf 4790 Mon Jun 6 18:29:01 2011 Jamie, JoeUpdateCDSCOMPLETE FRONT-END REBUILD (WITH PROBLEMS (fixed)) Today Joe and I undertook a FULL rebuild of all front end systems with the head of the 2.1 branch of the RCG. Here is the full report of what we did: 1. checked out advLigoRTS/branches/branch-2.1, r2457 into core/branches/branch-2.1 2. linked core/release to branches/branch-2.1 3. linked in models to core/release/src/epics/simLink using Joe's new script (userapps/release/cds/c1/scripts/link_userapps) 4. remove unused/non-up-to-date models: 5. c1dafi.mdc1lsp.mdlc1gpv.mdlc1sup_vertex_plant_shmem.mdl  6. modified core/release/Makefile so that it can find models: 7. --- Makefile (revision 2451)+++ Makefile (working copy)@@ -346,7 +346,7 @@ #MDL_MODELS = x1cdst1 x1isiham x1isiitmx x1iss x1lsc x1omc1 x1psl x1susetmx x1susetmy x1susitmx x1susitmy x1susquad1 x1susquad2 x1susquad3 x1susquad4 x1x12 x1x13 x1x14 x1x15 x1x16 x1x20 x1x21 x1x22 x1x23 #MDL_MODELS =(wildcard src/epics/simLink/l1*.mdl)-MDL_MODELS = $(shell cd src/epics/simLink; ls m1*.mdl | sed 's/.mdl//')+MDL_MODELS =$(shell cd src/epics/simLink; ls c1*.mdl | sed 's/.mdl//')  World: (MDL_MODELS) showWorld:  8. removed channel files for models that we know will be renumbered • For this rebuild, we are also building modified sus models, that are now using libraries, so the channel numbering is changing. 9. make World • this makes all the models 10. make installWorld • this installs all the models 11. Run activateDQ.py script to activate all the relevant channels • this script was modified to handle the new "_DQ" channels 12. make/install new awgtpman: 13. cd src/gdsmakecp awgtpman /opt/rtcds/caltech/c1/target/gds/bin 14. turn off all watchdogs 15. test restart one front end: c1iscex 16. ## BIG PROBLEM The c1iscex models (c1x01 and c1scx) did not come back up. c1x01 was running long on every cycle, until the model crashed and brought down the computer. After many hours, and with Alex's help, we managed to track down the issue to a patch from Rolf at r2361. The code included in that patch should have been wrapped in an "#ifndef RFM_DIRECT_READ". This was fixed and committed to branches/branch-2.1 at r2460 and to trunk at r2461. 17. update to core/branches/branch-2.1 to r2460 18. make World && make installWorld with the new fixed code 19. restarted all computers 20. restart frame builder 21. burt restored to 8am this morning 22. turned on all watchdogs Everything is now green, and things seem to be working. Mode cleaner is locked. X arm locked. 4789 Mon Jun 6 17:28:31 2011 steveUpdateComputersstill, no PEM channels  Quote: AA filter box was removed and modified at 1Y7 today. The -5V power supply was current limited when I plugged it back in. It was removed for medical attention. NO PEM channels available! because of this. D68L8EX-850Hz filter chips were removed and bypassed-shorted as Rana's entry on March 17, 2006 in old elog. This unit is still has a short somewhere. Attachment 1: P1070846.JPG 4788 Mon Jun 6 17:22:09 2011 valeraConfigurationLSCClipping in the X arm 1064 um trans path I changed optics in the ETMX transmon path to remove clipping (which made a false QPD signal). During the weekend I found that there was an offset in X arm c1ass pitch servo, which derives the signal by demodulating the arm cavity power, coming from the beam clipping in the transmon path. The clipping was on the pair of the 1" mirrors that steer the beam after the 2" lens (see attached picture). The beam is about 5-6 mm in diameter at this distance from the lens and was not well centered. I moved the steering mirrors downstream by about 8" where the beam is about 2-3 mm (the attached picture shows the mirrors in the new location). The Y arm layout is different from X arm and I didn't find any obvious clipping in transmon path. The max X arm buildup went up from 1.3 to 1.5. I changed the TRX gain from -0.003 to -0.002 to obtain the normalized X arm power of 1 in this state. The MC refl DC is 1.6 out of 4.9 V and the Y arm buildup is ~0.9 so the TRX(Y) gains will have to be adjusted once the MC visibility is maximized. Attachment 1: XarmTransMon.pdf 4787 Mon Jun 6 16:44:34 2011 KojiUpdateElectronicsPOY11 tested The full characterization of POY11 is found in the PDF. Resonance at 11.03MHz Q of 7.6, transimpedance 1.98kOhm shotnoise intercept current = 0.17mA (i.e. current noise of 7pA/rtHz) Notch at 21.99MHz Q of 56.2, transimpedance 35.51 Ohm Notch at 55.20MHz Q of 48.5, transimpedance 37.5 Ohm Attachment 1: POY11_test.pdf 4786 Mon Jun 6 02:09:39 2011 ranaUpdateElectronicsPOY11 Rework Nearly Complete I've finished tuning POY11 and it is now sitting on top of the analyzer waiting for Koji to test its noise. Notes: 1. R2 has been switched from a 50 -> 110 Ohm R and a (29 Ohm | 47 pF) in parallel to it. This makes the gain of the MAX4107 be ~20 above 100 MHz and ~5 around 11 MHz. The high gain at high frequency makes it stable (squashes the 200 MHz oscillation) and the low gain at low frequency is to prevent saturation (the raw 11 MHz transimpedance is too high). 2. There are two notches: 22.12 MHz and 55.3 MHz. 3. The TEST IN input has been disabled since it wasn't useful. 4. 107 Ohms inserted into between the U11 output and the TSENSE feedthrough. This is to prevent oscillations when driving the long Dsub cable. This needs to be done on all Gold Box RFPDs. 5. R4 -> 50 Ohms. 6. Had trouble tuning this to get the resonance at 11.06 MHz. This turned out to be the parallel inductance coming from L3 (previously 1.45 uH) whereas we needed a total inductance of ~1.6 uH. So I changed L3 to 33 uH to get it to be negligible compared to 1.7 uH at 11 MHz. This needs to be considered for all the 11 MHz diodes. Attachment 1: 777.png 4785 Sat Jun 4 15:26:04 2011 Larisa ThorneUpdateElectronicsSeismometer Box Update (continuation of this) Here are the transfer function and noise plots of the seismometer box, using the op amps that are actually indicated on the original plan (THS4131, AD826). I added them to the LISO op amp library (can be found in /cvs/cds/caltech/apps/linux64/liso/filter/opamp.lib) Next step is to compare the noise graph below to the seismic noise curve of the interferometer to verify that the seismometer box configuration won't affect the curve... Attachment 1: SeisBoxLISO_transfer.pdf Attachment 2: SeisBoxLISO_noise.pdf 4784 Fri Jun 3 18:12:03 2011 steveUpdateComputersno PEM channels AA filter box was removed and modified at 1Y7 today. The -5V power supply was current limited when I plugged it back in. It was removed for medical attention. NO PEM channels available! because of this. 4783 Fri Jun 3 14:27:32 2011 KojiUpdateElectronicsPOP55 test results The full characterization of POP55 is found in the PDF. Resonance at 54.49MHz Q of 2.5, transimpedance 241Ohm shotnoise intercept current = 4.2mA (i.e. current noise of 37pA/rtHz) Notch at 11.23MHz Q of 2.4, transimpedance 6.2 Ohm Notch at 110.80MHz Q of 53.8, transimpedance 13.03 Ohm Attachment 1: POP55_test.pdf 4782 Thu Jun 2 23:10:10 2011 KojiUpdateElectronicsREFL11 test results (Re: REFL11 fixed) The full characterization of REFL11 is found in the PDF. Resonance at 11.062MHz Q of 15.5, transimpedance 4.1kOhm shotnoise intercept current = 0.12mA (i.e. current noise of 6pA/rtHz) Notch at 22.181MHz Q of 28.0, transimpedance 23 Ohm Notch at 55.589MHz Q of 38.3, transimpedance 56 Ohm Attachment 1: REFL11_test.pdf 4781 Thu Jun 2 16:31:41 2011 JamieUpdateCDSaquired SUS channel name suffixes changed from _DAQ to _DQ CDS changed the suffix for all aquired channel names from _DAQ to _DQ. When we rebuilt the sus models, described in the previous log, the channel names were changed and consequently the channel files were completely rewritten. To fix the issue, the latest archived channel file was copied back into the chans directory, and the suffixes were changed, as so: cd /opt/rtcds/caltech/c1/chans cp archive/C1SUS_110602_155403.ini C1SUS.ini sed -i 's/DAQ/DQ/g' C1SUS.ini  We then restarted the models and the framebuilder. 4780 Thu Jun 2 16:23:42 2011 JamieUpdateSUSSUS control models updated to use new sus_single_control library part A new library part was made for the single suspension controller (it was originally made from the c1scx controller), using the following procedure: 1. Opened c1scx model (userapps/trunk/sus/c1/models/c1scx) 2. Cut ETMX subsystem block out of SUS subsystem 3. Pasted ETMX block into new empty library, and renamed it C1_SUS_SINGLE_CONTROL 4. Tweaked names of inputs, and generally cleaned up internals (cosmetically) 5. Saved library to: userapps/trunk/sus/c1/models/lib/sus_single_control.mdl Once the new sus_single_control library part was made and the library was committed to the cds_user_apps repo, I replaced all sus controller subsystems with this new part, in: • c1scx • c1scy • c1sus (x5 for each vertex mass) All models were rebuild, installed, and tested, and everything seems to be working fine. 4779 Thu Jun 2 10:19:37 2011 Alex IvanovSummaryDAQinstalled new daqd (frame builder) program on fb (target/fb/daqd) I hope that new daqd code will fix the problem with non-aligned at 16 seconds frame file GPS times. I have compiled new daqd program under /opt/rtcds/caltech/c1/core/release/build/mx and installed it under target/fb/daqd, then restarted daqd process on "fb" computer. It was installed with the ownership of user root and I did chmod +s on it (set UID on execution bit). This was done in order to turn on some code to renice daqd process to the value of -20 on the startup. Currently it runs as the lowest nice value (high priority). controls@fb /opt/rtcds/caltech/c1/target/fb ls -alt daqd
-rwsr-sr-x 1 root controls 6592694 Jun  2 10:00 daqd

Backup daqd is here:

controls@fb /opt/rtcds/caltech/c1/target/fb \$ ls -alt daqd.02jun11
-rwxr-xr-x 1 controls controls 6768158 Feb 21 11:30 daqd.02jun11

4778   Wed Jun 1 21:56:43 2011 KojiUpdateGeneralaLIGO BBPD / Green PD final result

Here is the conclusive result for the circuit configuration for aLIGO BBPD and 40m Green PD.

- Use Mini-circuits MAR-6SM for the RF preamplifier. The 50Ohm input impedance is used for the RF transimpedance.
The maximum output is ~4dBm.

- Use Mini-circuits GALI-6 for the RF middle power amp. The gain is 12dB and the amplifier is linear up to +17dBm. i.e. This is still linear at the maximum output level of MAR-6SM.

- The total RF transimpedance is ~2k. The DC transimpedance is also 2k.

- The bandwidth is 80MHz with FFD100 and internal 25V bias. When S3399 is used, the bandwdith goes up to 180MHz
although the responsivity of FFD100 at 1064nm is better than S3399 by a factor of 1.5. At the 40m we will use S3399 for the green BB PD.

- By adding an LC network next to the PD, one of the unnecessary signal can be notched out.
As an example, 9MHz notch was placed for the FFD100 case.

- Noise level: ~10pA/rtHz as a floor noise level at around 30MHz. This corresponds to the equivalent dark current of 0.4mA.

Matt has finished the PCB layout. We will order small first batches, and stuff it for the test. Some of these will be the 40m green PD.

Attachment 1: PD_response.pdf
Attachment 2: linearity_GALI_6.pdf
4777   Wed Jun 1 13:33:22 2011 koji, taraUpdateElectronicsTTFSS #7

We replaced GE81 by PZT2907A (PNP transistor) in TTFSS #7, it's working fine.

Last time I broke Q4 transistor, which is used in the low noise power module for TTFSS, (see the schematic) and could not find another PZT2907A, so GE81 was used temporarily. Now we changed it back to PZT2907A as designed.  I tested it by checking the voltage outputs of the board. It works fine, all voltage outputs are correct. I labeled one of the slot on the blue cabinet tower and kept the rest of the transistors there.

 Quote: I brought TTFSS set #7 to 40m and kept it in the electronic cabinet. note that Q4 transistor has not been replaced back to PZT2907A yet. It's still GE82. Q3 is now pzt3904, not PZT2222A.

4776   Wed Jun 1 11:31:50 2011 josephbUpdateCDSMC1 LR digital reading close to zero, readback ~0.7 volts

There appears to be a bad cable connection somewhere on the LR sensor path for the MC1 optic.

The channel C1:SUS-MC1_LRPDMon is reading back 0.664 volts, but the digital sensor channel, C1:SUS-MC1_LRSEN_INMON, is reading about -16.  This should be closer to +1000 or so.

We've temporarily turned off the LRSEN filter module output while this is being looked into.

I briefly went out and checked the cables around the whitening and AA boards for the suspension sensors, but even after wiggling and making sure everything was plugged in solidly.  There was one semi-loose connection, but it wasn't on the MC1 board, but I pushed it all the way in anyways.  The monitor point on the AA board looks correct for the LR channels, although ITMX LR struck me as being very low at about -0.05 Volts.

According to data viewer, the MC1 LR sensor channel went bad roughly two weeks ago, around 00:40 on 5/18 UTC, or 17:40 on 5/17 PDT.

UPDATE:

It appears the AA board (or possibly the SCSI cable connected to it) is the problem in the chain.

4775   Tue May 31 17:30:42 2011 steveUpdateSUSETMY damping restored

ETMY's watch dogs were found tripped. They were restored.

ELOG V3.1.3-