40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
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ID Date Author Typedown Category Subject
  15857   Wed Mar 3 12:00:58 2021 Paco, AnchalHowToIMCMC_F ASD

[Paco, Anchal]

- Saved BURT backup in /users/anchal/BURTsnaps/
- Copied existing code for mode cleaner noise budget from /users/rana/mat/mc. Will work on this from home to convert it inot new pynb way.

Get baseline IMC measurements (passive):
- MC_F:
  - What is MC_F? Let's find out.
  - On MC_F Cal window titled 'C1IOO-MC_FREQ', we turned off ON/OFF and back on again.
  - Using diaggui, we measured ASD of MC_F channel in units of counts/rtHz.

[Rana, Paco]

- Using diaggui, measured ASD from a template (under /users/Templates) and overlay the 1/f noise of the NPRO (Attachment 1)

[Anchal, Paco]

- WFS Master
  - Went through the schematic and tried to understand what is happening.
  - Accidentally switched on MC WF relief (python 3). Bunch of things were displayed on a terminal for a while and then we Ctrl-C it.
  - The only thing we noticed that change is a slight increase in WFS1 Yaw, and a corresponding decrease in WFS1 Pitch, WFS2 Pitch, and WFS2 Yaw.
  - We need to find out what this script does.


Future work:

  • Create an automated script for taking MC_F_DQ spectrum and refer it against reference trace.
  • Use pynb to create a noise budget for mode cleaner.
  • Identify excess noise between 10-40 Hz.
  • Configure output matrix in WFS Master to reduce the noise. Automate this process as well.
Attachment 1: 20210303_MC_F_Spectrum.pdf
20210303_MC_F_Spectrum.pdf
Attachment 2: 20210303_MC_F_Spectrum.tar.gz
  16085   Mon Apr 26 18:52:52 2021 Anchal, PacoHowToComputer Scripts / Programsawg free slot

Today we had some trouble launching an excitation on C1:IOO-MC_LSC_EXC from awggui. The error read:

awgSetChannel: failed getIndexAWG C1:SUS-MC2_LSC_EXC ret=-3

What solved this was the following :

  1. launch the dtt command line interface
  2. Anchal remembers a slot number 37008
  3. We issue >> awg free 37008
  4. Slot freed, launch a new instance of awggui
  16441   Sun Oct 31 14:21:31 2021 ranaHowToTreasureIFOCad

IFOcad model/video of the AEI 10m interferometer:

https://10m.aei.mpg.de/design-and-sensitivity/

  16467   Tue Nov 16 11:37:26 2021 HangHowToSUSFitting suspension model--large systematic errors

One goal of our sysID study is to improve the aLIGO L2A feedforward. Our algorithm currently improves only the statistical uncertainty and assumes the systematic errors are negligible. However, I am currently baffled by how to fit a (nearly) realistic suspension model...

My test study uses the damped aLIGO QUAD suspension model. From the Matlab model I extract the L2 drive in [N] to L3 pitch in [rad] transfer function (given by a SS model with the A matrix having a shape of 103x103). I then tried to use VectFIT to fit the noiseless TF. After removing nearby z-p pairs (defined by less than 0.2 times the lowest pole frequency) and high-frequency zeros, I got a model with 6 complex pole pairs and 4 complex zero pairs (21 free parameters in total). I also tried to fit the TF (again, noiseless) with an MCMC algorithm assuming the underlying model has the same number of parameters as the VectFIT results. 

Please see the first attached plots for a comparison between the fitted models and the true one. In the second plot, we show the fractional residual

    | TF_true - TF_fit | / | TF_true |,

and the inverse of this number gives the saturating SNR at each frequency. I.e., when the statistical SNR is more than the saturating value, we are then limited by systematic errors in the fitting. And so far, disappointingly I can only get an SNR of 10ish for the main resonances...

I wonder if people know better ways to reduce this fitting systematic... Help is greatly appreciated!

Attachment 1: L2L_L3P_fit.pdf
L2L_L3P_fit.pdf
Attachment 2: L2L_L3P_residual.pdf
L2L_L3P_residual.pdf
  16486   Mon Nov 29 15:24:53 2021 HangHowToGeneralFisher matrix vs length of each FFT segment

We have been discussing how does the parameter estimation depends on the length per FFT segment. In other words, after we collected a series of data, would it be better for us to divide it into many segments so that we have many averages, or should we use long FFT segments so that we have more frequency bins?

My conclusions are that:

1). We need to make sure that the segment length is long enough with T_seg > min[ Q_i / f_i ], where f_i is the resonant frequency of the i'th resonant peak and the Q_i its quality factor. 

2). Once 1) is satisfied, the result depends weakly on the FFT length. There might be a weak hint preferring a longer segment length (i.e., want more freq bins than more averages) though. 

=================================================================

To reach the conclusion, I performed the following numerical experiment.

I considered a simple pendulum with resonant frequency f_1 = 0.993 Hz and Q_1 = 6.23. The value of f_1 is chosen such that it is not too special to fall into a single freq bin. Additionally, I set an overall gain of k=20. I generated T_tot = 512 s of data in the time domain and then did the standard frequency domain TF estimation. I.e., I computed the CSD between excitation and response (with noise) over the PSD of the excitation. The spectra of excitation and noise in the readout channel are shown in the first plot. 

In the second plot, I showed the 1-sigma errors from the Fisher matrix calculation of the three parameters in this problem, as well as the determinant of the error matrix \Sigma = inv(Fisher matrix). All quantities are plotted as functions of the duration per FFT segment T_seg. The red dotted line is [Q_1/f_1], i.e., the time required to resolve the resonant peak. As one would expect, if T_seg <~ (Q_1/f_1), we cannot resolve the dynamics of the system and therefore we get nonsense PE results. However, once T_seg > (Q_1/f_1), the PE results seem to be just fluctuating (as f_1 does not fall exactly into a single bin). Maybe there is a small hint that longer T_seg is better. Potentially, this might be due to that we lose less information due to windowing? To be investigated further... 

I also showed the Fisher estimation vs. MCMC results in the last two plots. Here each dot is an MCMC posterior. The red crosses are the true values, and the purple contours are the results of the Fisher calculations (3-sigma contours). The MCMC results showed similar trends as the Fisher predictions and the results for T_seg = (32, 64, 128) s all have similar amounts of scattering << the scattering of the T_seg=8 s results. Though somehow it showed a biased result. In the third plot, I manually corrected the mean so that we could just compare the scattering. The fourth plot showed the original posterior distribution. 

 

Attachment 1: setup.pdf
setup.pdf
Attachment 2: Fisher_vs_Tperseg.pdf
Fisher_vs_Tperseg.pdf
Attachment 3: fisher_vs_mcmc_offset_removed.png
fisher_vs_mcmc_offset_removed.png
Attachment 4: fisher_vs_mcmc.png
fisher_vs_mcmc.png
  16980   Fri Jul 8 14:03:33 2022 JCHowToVACVacuum Preparation for Power Shutdown

[Koji, JC]

Koji and I have prepared the vacuum system for the power outage on Saturday.

  1. Closed V1 to isolate the main volume.
  2. Closed of VASE, VASV, VABSSCI,VABS, VABSSCO, VAEV, and VAEE.
  3. Closed V6, then close VM3 to isolate RGA
  4. Turn off TP1 (You must check the RPMs on the TP1 Turbo Controller Module)
  5. Close V5
  6. Turn off TP3 (There is no way to check the RPMs, so be patient)
  7. Close V4 (System State changes to 'All pneumatic valves are closed)
  8. Turn off TP2 (There is no way to check the RPMs, so be patient)
  9. Close Vacuum Valves (on TP2 and TP3) which connect to the AUX Pump.
  10. Turn of AUX Pump with the breaker switch wall plug.

From here, we shutdown electronics.

  1. Run /sbin/shutdown -h now on c1vac to shut the host down.
  2. Manually turn off power to electronic modules on the rack.
    • GP316a
    • GP316b
    • Vacuum Acromags
    • PTP3
    • PTP2
    • TP1
    • TP2 (Unplugged)
    • TP3 (Unplugged)

 

Attachment 1: Screen_Shot_2022-07-12_at_7.02.14_AM.png
Screen_Shot_2022-07-12_at_7.02.14_AM.png
  16985   Mon Jul 11 15:26:12 2022 JCHowToVACStartup after Power Outage

[Koji, Jc]

Koji and I began starting that Vacuum system up.

  1. Reverse order step 2 of shutting down electronics. Anthing after, turn on manually.
  2. If C1vac does not come back, then restart by holding the reset button.
  3. Open VA6
  4. Open VASE, VASV,VABSSCI, VABS, VABSSCO, VAEV, and VAEE
  5. Open V7
  6. Check P3 and P2, if they are at high pressure, approx. 1 Torr range, then you must use the roughing pumps.
  7. Connect Rotary pump tube. (Manually)
  8. Turn on AUX Pump
  9. Manually open TP2 and TP3 valves.
  10. Turn on TP2 and TP3, when the pumps finish startup, turn off Standby to bring to nominal speed.
  11. Turn on RP1 and RP3
  12. Open V6
  13. Once P3 reaches <<1 Torr, close V6 to isolate the Roughing pumps.
  14. When TP2 and TP3 are at nominal speed, open V5 and V4.
  15. Now TP1 is well backed, turn on TP1.
  16. When TP1 is at nominal speed, Open V1.
  16987   Mon Jul 11 17:41:52 2022 KojiHowToVACStartup after Power Outage

- Once the FRG gauge readings are back (see next elog by Tega), I could open V1 to pump down the main vacuum manifold.
- TP2/TP3 were brought back to stand-by mode (slower spinning)
- V7 was closed to separate the annuli side and TP1

During the vacuum recovery, I saw TPs were automatically turned on as soon as the backing pumps were engaged. I could not figure out what caused this automation.

Also, I saw some gate valve states changed while I was not touching them. e.g. V7 was close / VM3 was open / etc
I really had no idea what/who was handling these.

As of ~18:00 local, the main volume pressure is ~2e-5 torr and ready to open the PSL shutter.

Attachment 1: Screen_Shot_2022-07-11_at_18.13.00.png
Screen_Shot_2022-07-11_at_18.13.00.png
  17104   Thu Aug 25 15:24:06 2022 PacoHowToElectronicsRFSoC 2x2 board -- fandango

[Paco, Chris Stoughton, Leo -- remote]

This morning Chris came over to the 40m lab to help us get the RFSoC board going. After checking out our setup, we decided to do a very basic series of checks to see if we can at least get the ADCs to run coherently (independent of the DACs). For this I borrowed the Marconi 2023B from inside the lab and set its output to 1.137 GHz, 0 dBm. Then, I plugged it into the ADC1 and just ran the usual spectrum analyzer notebook on the rfsoc jupyter lab server. Attachment #1 - 2 shows the screen captured PSDs for ADCs 0 and 1 respectively with the 1137 MHz peaks alright.

The fast ADCs are indeed reading our input signals.


Before this simple test, we actually reached out to Leo over at Fermilab for some remote assistance on building up our minimally working firmware. For this, Chris started a new vivado project on his laptop, and realized the rfsoc 2x2 board files are not included in it by default. In order to add them, we had to go into Tools, Settings and add the 2020.1 Vivado Xilinx shop board repository path to the rfsoc2x2 v1.1 files. After a little bit of struggling, uninstalling, reinstalling them, and restarting Vivado, we managed to get into the actual overlay design. In there, with Leo's assistance, we dropped the Zynq MPSoC core (this includes the main interface drivers for the rfsoc 2x2 board). We then dropped an rf converter IP block, which we customized to use the right PLL settings. The settings, from the System Clocking tab were changed to have a 409.6 MHz Reference Clock (default was 122.88 MHz). This was not straightforward, as the default sampling rate of 2.00 GSPS was not integer-related so we had to also update that to 4.096 GSPS. Then, we saw that the max available Clock Out option was 256 MHz (we need to be >= 409.6 MHz), so Leo suggested we dropped a Clocking Wizard block to provide a 512 MHz clock input for the rfdc. The final settings are captured in Attachment # 3. The Clocking Wizard was added, and configured on its Output Clocks tab to provide a Requested Output Freq of 512 MHz. The finall settings of the Clocking wizard are captured in Attachment #4. Finally, we connected the blocks as shown in Attachment #5.

We will continue with this design tomorrow.

Attachment 1: adc0_1137MHz.png
adc0_1137MHz.png
Attachment 2: adc1_1137MHz.png
adc1_1137MHz.png
Attachment 3: rfdc_PLLsettings.png
rfdc_PLLsettings.png
Attachment 4: clockingwiz_settings.png
clockingwiz_settings.png
Attachment 5: blockIPdiag.png
blockIPdiag.png
  17194   Mon Oct 17 17:42:35 2022 JCHowToOPLEV TablesIMC Reflected beam sketch

I sketched up a quick drawing with estimated length for the IMC reflected beam. This includes the distances and focal length. Distances are from optic to optic. 

Attachment 1: Screenshot_2022-10-18_093033.png
Screenshot_2022-10-18_093033.png
  17277   Thu Nov 17 11:24:39 2022 JCHowToLSCLocking MICH

[Yuta, JC]

Here is the Yuta's Alignment Scheme from elog 17056  with these slight adjustments:

Current alignment scheme:
Current alignment scheme I figured out is the following.
 - Check Y green. If it is transmitted at good spot on GTRY camera, Yarm is OK. If not, tweak ITMY/ETMY. alignment.
 - Mis-align AS4, align TT1, TT2, LO1 to have BHDC_A_OUT of ~115 and BHDC_B_OUT of ~95.
 - Align PR3, PR2 to maximize TRY_OUT to ~1.0
 - Tweak ITMY/ETMY if the beam spot on them are not good.
 - Align BS, ITMX to have good MICH fringe and TRX_OUT to ~1.0.
 - Tweak ITMX/ETMX if the beam spot on them are not good.
 - Misalign ETMY, ETMX, ITMY to have LO-ITMX fringe in BHD DCPDs. From Sitemap --> BHD --> Homodyne Phase Ctrl --> LO_PHASE --> Turn ON LO Phase Servo (This will lock LO and ITMX fringe) --> align AS beam with SR2 and AS4 differentially, with ratio of AS4/SR2=3.6 for YAW, with ratio of AS4/SR2= 4.5 for PITCH to have BHDC_A_OUT ~ 50.
 - Restore ITMY alignment, and lock MICH.

  173   Thu Dec 6 15:21:59 2007 albertoFrogsElectronicsRF Transfer Function of Stiff Aluminum Wires
Transfer function of 3cm long Aluminum wires and of 3cm stranded wires
Attachment 1: TF_3cm_stiff_wires.amplitude.png
TF_3cm_stiff_wires.amplitude.png
Attachment 2: DSC_0225compressed.JPG
DSC_0225compressed.JPG
Attachment 3: TF_3cm_stranded_wires.amplitude.png
TF_3cm_stranded_wires.amplitude.png
  189   Wed Dec 12 22:24:48 2007 tobinFrogsPEMweather station
I poked at the weather station briefly this evening.

* There's almost nothing in the elog about it.
* It exists. It is located on the North wall, just north of the beam splitter.
* It seems to be displaying reasonable data for the indoors, but nothing for the outdoor sensors.
* c1pem didn't seem to be starting up (couldn't telnet into it, etc). I altered its startup file and reset it several times, and eventually it came to life.
* the weather station has a serial cable that goes all the way to c1pem. I plugged it in.
* however, the Weather.st program complains "NO COMM"--it gets no data from the weather station
* The next thing to do is to plug in a laptop to that serial cable and see if the weather station can be convinced to talk.
  340   Sun Feb 24 10:51:58 2008 tfFrogsEnvironment40m in phdcomics?
  581   Fri Jun 27 09:20:15 2008 steveFrogsPEMdust particle count is up & alarm handler is on
This 3 years plot show the trend of seasons.
When outside air quality goes bad ( 0.5 micron > 1 million ) the lab follows.
I will demonstrate this effect with a 4th of July fire works calibration.
Let's do not forget the construction activity next door either.

The alarm handler is busy:
It's sound level were reset to a modest level yesterday.
It would be nice to change the alarm sound so it can play Wagner:Der Ring des Nibelungen:
Das Rheingold, Die Walkure & Siegfried and Gotterdammerung
or something more appropriate than the present frog call

1, half micron count is climbing ( it's close to 16k now )
2, MZ refl signal is too high
3, MC lenght servo LO is too
Attachment 1: dust3y.jpg
dust3y.jpg
  666   Mon Jul 14 10:57:00 2008 KojiFrogsEnvironmentSomeone at 40M sent LHO water of life
Someone at the 40m sent Mike@LHO a pound of peets coffee with the name of Koji Arai.
It was a good surprise! Thanks, we will enjoy it!
I will return to Pasadena next week. See you then.
  877   Mon Aug 25 11:43:55 2008 YoichiFrogsIOOMC REFL PD cable had been disconnected through out the weekend
Most of my morning was wasted by the MC REFL PD cable, which was disconnected on the generic LSC PD interface board.
I know who did this. *ME*. When I pulled out the MC board, which is sitting next to the PD interface, on Friday, I must have
disconnected the PD cable accidentally. The connector of the PD cable (D-Sub) does not have screws to tighten and easily comes off.
I wrote this entry to warn other people of this potential problem.
  976   Mon Sep 22 15:02:45 2008 ranaFrogsTreasureMantis found outside the 40m door at night
Attachment 1: mantis.JPG
mantis.JPG
  1268   Tue Feb 3 15:01:38 2009 AlbertoFrogsComputersmegatron slow?

I notice that Megatron is slower than any other computer in running code that invokes optickle or looptickle (i.e. three times slower than Ottavia). Even without the graphics.

Has anyone ever experienced that?

  1275   Thu Feb 5 16:21:07 2009 JenneFrogsComputersBelladonna connects to the wireless Martian network again

Symptoms:  Belladonna could not (for a while) connect to the wireless network, since there was a driver problem for the wireless card.  This (I believe) started when Yoichi was doing updates on it a while back.

The system: Belladonna is a Dell Inspirion E1505 laptop, with a Broadcom Corporation Dell Wireless 1390 WLAN Mini-PCI Card (rev 01)

Result:  Belladonna now can talk to it's wireless card, and is connected to the Martian network.  (MEDM and Dataviewer both work, so it must be on the network.)

 

What I did:

0.  Find a linux forum with the following method:  http://www.thelinuxpimp.com/main/index.php?name=News&file=article&sid=749

The person who wrote this has the exact same laptop, with the same wireless card.

1.  Get a new(er) version of ndiswrapper, which "translates" the Windows Driver for the wireless card to Linux-ese.  Belladonna previously was using ndiswrapper-1.37.

$wget http://nchc.dl.sourceforge.net/sourceforge/ndiswrapper/ndiswrapper-1.42.tar.gz

2.  Put the ndiswrapper in /home/controls/Drivers, and installed it.

$ndiswrapper -i bcmwl5.inf  3.  Get and put the Windows driver in /home/controls/Drivers/WiFi

$wget http://ftp.us.dell.com/network/R140747.EXE
4. Unzip the driver $unzip -a R140747.EXE

5.  Make Fedora use ndiswrapper

$ndiswrapper -m

$modprobe ndiswrapper

6. Change some files to make everything work:

/etc/sysconfig/wpa_supplicant      CHANGE FROM: DRIVERS="-Dndiswrapper"     CHANGE TO: DRIVERS="-Dwext"

/etc/sysconfig/network-scripts/ifcfg-wlan0      CHANGE FROM: BOOTPROTO=none      CHANGE TO: BOOTPROTO=dhcp

/etc/rc.d/init.d/wpa_supplicant        CHANGE FROM: daemon $prog -c $conf $INTERFACES $DRIVERS -B        CHANGE TO: daemon $prog -c$conf $INTERFACES $DRIVERS -B

6.  Restart things

$service wpa_supplicant restart
$service network restart

7.  Restart computer (since it wasn't working after 1-6, so give a restart a try)

8. Success!!!  MEDM and Dataviewer work without any wired internet connection => wireless card is all good again!

  1479   Mon Apr 13 18:57:03 2009 AlbertoFrogsComputersGPIB/ETH Interface Troubles

I really don't understand why my programs that I used to use to get data from the HP Spectrum Analyzer and the Marconi frequency generator don't work anymore.

I spent hours trying to debug the code but I can't sort the problem out.

The main problem seem to be with the function recv from the socket library. Somehow it can't anymore get any data from the instruments. The thing I can't understand, though, is that if called directly from the python terminal it works fine!

In particular the problem is with the following lines in my code:

netSock.send("mkpk;mka?\n")
netSock.send("++read eoi\n")
tmp = netSock.recv(1024)

Tried a lot of tickering but it didn't work.

I attach the two scripts I've been using. One (sweepfrequencyPRC.py) calls the other (HP4395PRC.py).

They worked egregiously for weeks in the past. Don't know what happened since then.

Attachment 1: sweepfrequencyPRC.py
## sweepfrequency.py [-f filename] [-i ip_address] [-a startFreq] [-z endFreq] [-s stepFreq] [-m numAvg]
#
## This script sweeps the frequency of a Marconi local oscillator, within the range
## delimited by startFreq and endFreq, with a step set by stepFreq. An arbitary
## signal is monitored on a HP8590 spectrum analyzer and the scripts records the
## amplitude of the spectrum at the frequency injected by the Marconi at the moment.

## The GPIB address of the Marconi is assumed to be 17, that of the HP Spectrum Analyzer to be 18

## Alberto Stochino, October 2008
... 53 more lines ...
Attachment 2: HP8590PRC.py
# This function provides the measuremeent of the peak amplitude on the spectrum analyzer
# HP8590 analyzer while sweeping the excitation frequency on the function generator.
#
# Alberto Stochino 2008

import re
import sys
import math
from optparse import OptionParser
from socket import *
... 70 more lines ...
  1481   Tue Apr 14 12:10:11 2009 AlbertoFrogsComputersGPIB/ETH Interface Troubles

Quote:

I really don't understand why my programs that I used to use to get data from the HP Spectrum Analyzer and the Marconi frequency generator don't work anymore.

I spent hours trying to debug the code but I can't sort the problem out.

The main problem seem to be with the function recv from the socket library. Somehow it can't anymore get any data from the instruments. The thing I can't understand, though, is that if called directly from the python terminal it works fine!

In particular the problem is with the following lines in my code:

netSock.send("mkpk;mka?\n")
netSock.send("++read eoi\n")
tmp = netSock.recv(1024)

Tried a lot of tickering but it didn't work.

I attach the two scripts I've been using. One (sweepfrequencyPRC.py) calls the other (HP4395PRC.py).

They worked egregiously for weeks in the past. Don't know what happened since then.

This morning Joe looked at my code and made me notice that for some reason the query to the Spectrum Analyzer made by netSock.recv(1024) contained two answers. It was like the buffer contained the answer two different queries.

After some experiment I found that basically the GPIB interface wasn't switching from the "auto 1" to the "auto 0" mode as it should. I rewrote part of the code and that seemed have solved the problem.

Still don't understand why it used to work in the past and then it stopped.

  1911   Sat Aug 15 18:35:14 2009 ClaraFrogsComputersHow far back is complete data really saved? (or, is the cake a lie?)

I was told that, as of last weekend, we now have the capability to save full data for a month, whereas before it was something like 3 days. However, my attempts to get the data from the accidentally-shorted EW2 channel in the Guralp box have all been epic failures. My other data is okay, despite my not saving it for several days after it was recorded. So, my question is, how long can the data actually be saved, and when did the saving capability change?

  2049   Mon Oct 5 09:31:05 2009 AlbertoFrogsPSLPSL laser accidentally turned off

Alberto, Steve,

While I was moving a cart near by the PSL table I pushed the red emergency button that turns off the PSL laser. We had to unlock the button and then power cycle the laser driver to turn the laser back on.

I relocked MZ, FSS, PMC and I'm now waiting for the power to finish ramping up back to the previous value.

  2219   Mon Nov 9 16:32:36 2009 AlbertoFrogsEnvironmentShot of the white board yesterday before erasing

Yesterday Rana and I needed some room on the white board in the Control Room. We had to erase some of the stuff present on the board despite the bif warning "Do Not Erase".

This is how it looked like before erasing.

DSC_0980.JPG

Attachment 1: DSC_0980.JPG
DSC_0980.JPG
  2220   Mon Nov 9 18:27:30 2009 AlbertoFrogsComputersOMC DCPD Interface Box Disconnected from the power Supply

This afternoon I inadvertently disconnected one of the power cables coming from the power supply on the floor next to the OMC cabinet and going to the DCPD Interface Box.

Rob reconnected the cable as it was before.

  2236   Wed Nov 11 12:29:44 2009 AlbertoFrogsPSLMC Locked on the wrong mode?

This morning, after Steve pointed out that the readout RFAMPD_DC was zero, I thought of realigning the beam on the photodiode. Maybe I touched the lens or the beam splitter that send the beam on the diode when I installed an other beam splitter to make the measurement of the calibration between two ThorLabs PDA255 photodiodes.

After aligning the beam on the RFAMPD, the voltage of the DC readout was lower than it used to be (C1:IOO-RFAMPD_DC ~ 0.4 now vs. 4 as it was on November 4th).

I maximized the DC readout but the problem seems to be that the beam spot is not a round TEM00. In particular the spot looks like that of a TEM10 mode.

Since we're looking at the MC transmitted beam, is it possible that the MC is locked on the wrong mode?

Check out the attached picture.

Attachment 1: PB110184-1.JPG
PB110184-1.JPG
  2296   Thu Nov 19 08:53:12 2009 peteFrogsEnvironmentdiesel fumes

 Instead of doing RCG stuff, I went to Millikan to work on data analysis as I couldn't stand the fumes from the construction.  (this morning, 8am) 

  2377   Thu Dec 10 08:43:25 2009 steveFrogsEnvironmentdiesel fumes are less

Quote:

 Instead of doing RCG stuff, I went to Millikan to work on data analysis as I couldn't stand the fumes from the construction.  (this morning, 8am) 

 Diesel fumes are pumped away from control room AC intakes  with the help of newly installed  reflector boxes on the CES wall  fans.........see # 2272

Attachment 1: P1050817.JPG
P1050817.JPG
  2560   Tue Feb 2 15:30:03 2010 AlbertoFrogsTreasureWild Oats
FYI. Sitting on the top shelf of George I found an opened jar of raspberry jam and an opened jar of creamy peanut butter. Both are branded Wild Oats Market.
 
Wikipedia:
"Wild Oats Markets was an operator of natural foods stores and farmers markets in North America... Whole Foods officially completed their buyout of Wild Oats on August 27, 2007 [...]"
  3004   Fri May 28 07:13:05 2010 AlbertoFrogsGreen LockingSR785 found abandoned next to the workbenches

A poor lonely SR785 was found this morning roaming around in the lab in evident violation of the fundamental rule which requires all the equipment on carts to be brought back inside the lab right after use.

The people and the professors related to the case should take immediate action to repair for their misdeed.

  3131   Tue Jun 29 08:55:18 2010 JenneFrogsEnvironmentWe're being attacked!

Infested_InvasionOfKillerBugs.jpg

We're going to have to reinstate the policy of No food / organic trash *anywhere* in the 40m.  Everyone has been pretty good, keeping the food trash to the one can right next to the sink, but that is no longer sufficient, since we've been invaded by an army of ants:

AntInvasion_small.jpg

We are going back to the old policy of Take your trash out to the dumpsters outside.  I'm sure there are some old wives tales about how exercise after eating helps your digestion, or something like that, so no more laziness allowed!

  3421   Fri Aug 13 15:29:35 2010 AidanFrogsPhotosHere's the 40m team
Attachment 1: 40m_team.JPG
40m_team.JPG
  3424   Mon Aug 16 13:33:06 2010 ZachFrogsPhotosHere's the 40m team

 One day I'll get to be part of the krew

  3512   Thu Sep 2 01:48:23 2010 JenneFrogsTreasureNot cool....

This totally creeped me out when I found it wandering around on the floor not so far from my desk:

CreepyBug.jpg

  3520   Fri Sep 3 11:03:41 2010 AlbertoFrogsElectronicsCable cutting tools

I found this very interesting German maker of cool cable cutting tools. It's called Jokari.

We should keep it as a reference for the future if we want to buy something like that, ie RF coax cable cutting knives.

http://www.jokari.de/en.htm

  3522   Fri Sep 3 13:04:30 2010 KojiFrogsElectronicsCable cutting tools

Yeah, this looks nice.

And I also like to have something I have attached. This is "HOZAN P-90", but we should investigate American ones
so that we can cut the wires classified by AWG.

Quote:

I found this very interesting German maker of cool cable cutting tools. It's called Jokari.

We should keep it as a reference for the future if we want to buy something like that, ie RF coax cable cutting knives.

http://www.jokari.de/en.htm

 

Attachment 1: P90.jpg
P90.jpg
  3598   Thu Sep 23 10:34:20 2010 ranaFrogsComputersnodus gracefully rebooted

SVN down

mafalda down

I am guessing that the NFS file system hangup may have caused some machines to get into an awkward state. We may be best off doing a controlled power cycle of everything...

  3599   Thu Sep 23 11:15:20 2010 KojiFrogsComputersnodus gracefully rebooted

svn is back after starting apache on nodus.

http://lhocds.ligo-wa.caltech.edu:8000/40m/ApacheOnNodus

Quote:

SVN down

mafalda down

I am guessing that the NFS file system hangup may have caused some machines to get into an awkward state. We may be best off doing a controlled power cycle of everything...

 

  3601   Thu Sep 23 13:16:57 2010 KojiFrogsComputersnodus gracefully rebooted

mafalda is up now.

I found that the cable for mafalda (the sole red cable) had a broken latch.
The cable was about falling off from the switch. As a first-aid, I used this technique to put a new latch, and put it into the switch.

Now I can logged in it. I did not rebooted it.

Quote:

SVN down

mafalda down

I am guessing that the NFS file system hangup may have caused some machines to get into an awkward state. We may be best off doing a controlled power cycle of everything...

 

  3682   Fri Oct 8 17:36:16 2010 steveFrogsPhotosvisiting undergrads

Prof Alan Weistein guided the 24 student through the 40m. His performance was rated as  an enthusiastic 9.5

Attachment 1: P1060916.JPG
P1060916.JPG
Attachment 2: P1060921.JPG
P1060921.JPG
Attachment 3: P1060922.JPG
P1060922.JPG
Attachment 4: P1060915.JPG
P1060915.JPG
  4319   Thu Feb 17 23:41:46 2011 ranaFrogsDAQFrames Directory got the wrong name: Data unreachable

DTT stopped working for recent data. An 'ls' in the frames/full/ directory reveals:

drwxr-xr-x 2 controls controls 258048 Feb  3 12:26 9807
drwxr-xr-x 2 controls controls 258048 Feb  4 16:13 9808
drwxr-xr-x 2 controls controls 262144 Feb  5 19:59 9809
drwxr-xr-x 2 controls controls 258048 Feb  6 23:46 9810
drwxr-xr-x 2 controls controls 258048 Feb  8 03:33 9811
drwxr-xr-x 2 controls controls 262144 Feb  9 07:19 9812
drwxr-xr-x 2 controls controls 253952 Feb 10 11:06 9813
drwxr-xr-x 2 controls controls 266240 Feb 11 14:53 9814
drwxr-xr-x 2 controls controls 266240 Feb 12 18:39 9815
drwxr-xr-x 2 controls controls 266240 Feb 13 22:26 9816
drwxr-xr-x 2 controls controls 262144 Feb 15 02:13 9817
drwxr-xr-x 2 controls controls 253952 Feb 16 05:59 9818
drwxr-xr-x 2 controls controls 241664 Feb 17 09:46 9819
drwxr-xr-x 2 controls controls  28672 Feb 17 12:22 9820
drwxr-xr-x 2 controls controls  32768 Feb 17 15:06 6663
drwxr-xr-x 2 controls controls  73728 Feb 17 23:39 6664
controls@fb /frames/full $ date
Thu Feb 17 23:39:27 PST 2011

  4442   Fri Mar 25 01:27:29 2011 mevansFrogsGreen Lockingdigital frequency counting

Today we tried the Schmitt trigger DFD, and while it works it does not improve the noise performance.  At least part of our problem is coming from the discrete nature of our DFD algorithm, so I would propose that an industrious day job person codes up a new DFD which avoids switching.  We can probably do this by mixing the input signal (after high-passing) with a time-delayed copy of itself... as we do now, but without the comparator.  This has the disadvantage of giving an amplitude dependent output, but since we are working in the digital land we can DIVIDE.  If we mix the signal with itself (without delay) to get a rectified version, and low-pass it a little, we can use this for normalization.  The net result should be something like:

output = LP2[ s(t) * s(t - dt) / LP1[ s(t) * s(t) ]],

where s(t) is the high-passed input and LP is a low-pass filter.  Remember not to divide by zero.

 

  4444   Fri Mar 25 11:16:19 2011 josephbFrogsGreen Lockingdigital frequency counting

I modified the c1gfd.mdl simulink model.  I made a backup as c1gfd_20110325.mdl. 

The first change was to use a top_names block to put everything in.  The block is labeled ALS.  So all the channels will now be C1:ALS-GFD_SOMETHING.  This means medm channel names will need to be updated.  Also, the filter modules need to be updated in foton because of this.

I then proceeded to add the suggested changes made by Matt.  To avoid a divide by zero case, I added a saturation part which saturates at 1e-9 (note this is positive) and 1e9.

Quote:

Today we tried the Schmitt trigger DFD, and while it works it does not improve the noise performance.  At least part of our problem is coming from the discrete nature of our DFD algorithm, so I would propose that an industrious day job person codes up a new DFD which avoids switching.  We can probably do this by mixing the input signal (after high-passing) with a time-delayed copy of itself... as we do now, but without the comparator.  This has the disadvantage of giving an amplitude dependent output, but since we are working in the digital land we can DIVIDE.  If we mix the signal with itself (without delay) to get a rectified version, and low-pass it a little, we can use this for normalization.  The net result should be something like:

output = LP2[ s(t) * s(t - dt) / LP1[ s(t) * s(t) ]],

where s(t) is the high-passed input and LP is a low-pass filter.  Remember not to divide by zero.

 

 

Attachment 1: C1GFD.png
C1GFD.png
  4447   Mon Mar 28 16:19:23 2011 steveFrogsPhotosvisithing 5th graders

Suresh is captivating his audience with gravity waves on last Friday, March 25

Attachment 1: P1070475.JPG
P1070475.JPG
  4597   Mon May 2 13:43:05 2011 steveFrogsPhotosbirthday boys

.....Happy.... Birthday.... to.... Joseph... and... Jamie...Happy....Birthday..... to.... You............sing with us........Happy Birthday.....to you

Attachment 1: P1070622.JPG
P1070622.JPG
  4615   Tue May 3 15:59:22 2011 steveFrogsPhotosX-mas comes early

The little red all terrain cargo wagon 40" x 18"  has just arrived on pneumatic wheels.

Model #29, 200 lbs max load at 26 PSI,  minimum age requirement 1.5 years

Attachment 1: P1070634.JPG
P1070634.JPG
  5020   Fri Jul 22 17:01:41 2011 Iron ManFrogsGeneralProof that Alberto lived through his Iron Man!

Alberto_IronMan_small.jpgIronman Vineman 70.3 logo

print 208 Alberto Stochino 67/129 585/1376 36:02 1:52 830 6:41 2:38:58 21.1 296 4:58 56:33 2:13:40 - 5:40:19
 
  7758   Wed Nov 28 21:42:21 2012 ranaFrogsComputer Scripts / Programsdataviewer font error

An error this evening on rossa: dataviewer not working due to some font errors:

controls@rossa:~ 0$ dataviewer
Connecting.... done
Warning: Not all children have same parent in XtManageChildren
Warning: Not all children have same parent in XtManageChildren
Warning: Not all children have same parent in XtManageChildren
Warning: Not all children have same parent in XtManageChildren
Warning: Not all children have same parent in XtManageChildren
Warning:
    Name: FilterText
    Class: XmTextField
    Character '\52' not supported in font.  Discarded.

Warning:
    Name: FilterText
    Class: XmTextField
    Character '\56' not supported in font.  Discarded.

Warning:
    Name: FilterText
    Class: XmTextField
    Character '\170' not supported in font.  Discarded.

Warning:

etc.............

  7950   Mon Jan 28 21:36:44 2013 tall guyFrogsGeneralsmall people on notice

If I catch anyone putting small booties into the large bootie bin, I will make said person eat small booties.

ELOG V3.1.3-