 Mon Jun 11 22:18:18 2018, keerthana, Update, elog, Comparison of the analytical and finesse values of TMS and FSR.
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Oopss !! I made a mistake while taking the values from my notes. Sorry.
Quote:
> The percentage error which I found out =[(analytical value - finesse value)/analytical value]*100 |
 Wed Jun 13 11:59:03 2018, keerthana, Update, elog, command line enabled code for frequency scanning
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I have modified the code for frequency scanning and have made it completely command line enabled. The code is written in python. It is saved in the name
"frequency_scanning_argparse.py". I have uploaded it to the Mode-Spectroscopy Github repository.
Inorder to use this code there are two ways. |
Thu Jun 21 13:24:00 2018, keerthana, Update, elog, The cavity scan data of June 20 
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(Jon, Keerthana, Sandrine)
We tried to align the AUX and PSL laser yesterday. We collected the data from the spectrum analyser for the Y-ARM reflection and also for the
Y-ARM transmission from the ETM mirror. I am attaching the plots here. |
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Thu Jul 5 17:33:36 2018, keerthana, sandrine, Update, elog, Lights not working
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N/S ARM FL.
N/S ARM INC.
These two lights inside the 40m-lab are not working. |
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Thu Jul 5 17:58:04 2018, keerthana, sandrine, Update, elog,
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(Analisa, Sandrine, Keerthana)
Today Annalisa helped us to understand the new set up used to make the frequency scans of the AUX laser. While tracking the cables it seemed
that there were quite a lot of cables near the mixer. So we have reconnected one of the splitter which was splitting the RF out put signal from the Agilent |
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Thu Jul 12 14:06:39 2018, keerthana, Update, elog, Finesse and Analytical solution - Comparison
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I tried to compare the cavity scan data we get from the Finesse simulation and that we expect from the Analytical solution. The diagram of the cavity
I defined in Finesse is given below along with the values of different quantities I used. For the analytical solution I have used two different equations
and they are listed below. |
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Fri Dec 7 19:42:47 2018, rana, Frogs, elog, can't upgrade DokuWiki because of PHP / SL7
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All of our wikis (except the 40m one which unfortunately got turned into ligo.org mess) use DokuWiki. This now has an auto-upgrade feature through the
Admin web interface.
I tried this recently and it fails with this message: |
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Fri Mar 13 12:48:47 2020, Larry Wallace, Update, elog, Cert Renewal
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| Updated the cert in /etc/httpd/ssl. The new cert is good until March 12, 2022. |
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Fri Apr 16 11:31:00 2021, rana, Update, elog, elog stuck ~10 AM today
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| found it unresponsive. Restarted fine using procedure documented in wiki |
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Tue May 21 17:03:45 2013, Steve, Update, endtable upgrade, enclosure tops are sealed
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Quote:
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Thu May 23 12:02:48 2013, Steve, Update, endtable upgrade, ETMY - oplev
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Temporary oplev in place. The spot on the qpd is still big. My two lens solution did not work.
I will finalize optical component position of the oplev after the the arm transmitted and green beam optics in place. They have priority.
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Thu May 30 11:10:00 2013, Steve, Update, endtable upgrade, ETMY - oplev
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Quote:
Temporary oplev in place. The spot on the qpd is still big. My two lens solution did not work. |
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Thu May 30 20:45:53 2013, Annalisa, Update, endtable upgrade, ETMY - oplev
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Quote:
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Fri May 31 11:15:01 2013, Annalisa, Update, endtable upgrade, ETMY - Mode Matching for green - new calculation
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Since the beam waist after the Faraday had changed since the last time I measured it (maybe alignment changed a bit), I made a new mode matching
calculation for green. I attached the results.
I'm going to align the beam into the Yarm. |
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Tue Jun 4 10:44:13 2013, Steve, Update, endtable upgrade, PI pzt holders are ready
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The PI pzt holders are back from the shop. They are numbered 1, 2 & 3 and machined to match.
Tapered black delrin opener is to gauge the gap if it is too small to fit pzt. This is to prevent holder to be opened too much. |
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Thu Jun 6 09:58:13 2013, Steve, Update, endtable upgrade, enclosure to chamber connection
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Thin wall connector from McMCarr#55275K25 was tested in 150 mW, 1 mm beam
size of 1064 nm overnight. It did not show any degradation. |
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Tue Jun 25 19:18:07 2013, gautam, Configuration, endtable upgrade, plan of action for PZT installation
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This entry is meant to be a sort of inventory check and a tentative plan-of-action
for the installation of the PZT mounted mirrors and associated electronics on the Y-endtable.
Hardware details: |
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Wed Jul 3 21:19:04 2013, gautam, Configuration, endtable upgrade, plan of action for PZT installation
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This is an update on the situation as far as PZT installation is concerned. I measured the required cable (PZT driver board to PZT) lengths for
the X and Y ends as well as the PSL table once again, with the help of a 3m long BNC cable, just to make sure we had the lengths right. The quoted cable
lengths include a meter tolerance. The PZTs themselves have cable lengths of 1.5m, though I have assumed that this will be used on the tables themselves. |
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Mon Jul 8 13:45:19 2013, gautam, Configuration, endtable upgrade, Driver board verification
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With the help of an expansion card, I verified that the + 15V and + 24V from the eurocrate in the slot I've identified
for the PZT driver boards are making their way to the board. The slot is at the right-most end of the eurocrate in 1Y4, and the rack door was getting in
the way of directly measuring these voltages once I hooked up the driver board to the expansion card. So I just made sure that all the LEDs on the expansion |
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Wed Jul 10 22:41:06 2013, gautam, Configuration, endtable upgrade, PZT Driver Board
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| I did the following with the PZT Driver Board: |
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Thu Jul 11 09:15:10 2013, Steve, Update, endtable upgrade, ETMY optable grounded
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ETMY optical table top was grounded to the ETMY chamber through 1 Mohms this morning. I also strain releifed relieved a few cables
that were pulling on components directly. |
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Mon Jul 15 11:51:18 2013, gautam, Configuration, endtable upgrade, DAC at 1Y4-Max Output and Power Spectrum
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Summary:
I measured the maximum output of the DAC at 1Y4 as well as its power spectrum. The results are as follows (plots below):
Maximum amplitude of differential output: + 10V.
Power spectrum has a peak at 64 kHz.
Therefore, |
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Mon Jul 15 13:51:17 2013, Koji, Configuration, endtable upgrade, DAC at 1Y4-Max Output and Power Spectrum
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We need the unit of the voltage power spectrum density to be V/sqrt(Hz).
Otherwise we don't understand anything / any number from the plot. |
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Mon Jul 15 15:54:20 2013, gautam, Configuration, endtable upgrade, DAC at 1Y4- Power Spectrum -with the right units
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Quote:
We need the unit of the voltage power spectrum density to be V/sqrt(Hz). |
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Mon Jul 15 17:20:43 2013, Jenne, Configuration, endtable upgrade, DAC at 1Y4- Power Spectrum -with the right units
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Those 'peaks' for the oscillations seem ridiculously broad. I think you should look again, really quickly, with smaller bandwidth at, say, the
2kHz oscillation, to make sure it looks reasonable. |
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Mon Jul 15 17:59:31 2013, gautam, Configuration, endtable upgrade, DAC at 1Y4- Power Spectrum -6.4kHz bandwidth
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Quote:
Those 'peaks' for the oscillations seem ridiculously broad. I think you should look again, really quickly, with smaller bandwidth at, |
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Tue Jul 16 14:51:09 2013, gautam, Configuration, endtable upgrade, AI Board-D000186-Modified notches
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I tried shifting the notch frequencies on the D000186-revision D board given to me by Koji. The existing notches were at ~16 kHz and ~32 kHz. I
shifted these to notches at ~64 kHz and ~128 kHz by effecting the following changes (see schematic for
component numbering) on Channel 8 of the board-I decided to check things out on one channel before implementing changes en masse: |
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Thu Jul 18 19:09:08 2013, gautam, Configuration, endtable upgrade, QPD Calibration for PZT Calibration
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Summary
I have been working on setting up a QPD which can eventually be used to calibrate the PZT, and also orient the PZT in the mount such that the pitch
and yaw axes roughly coincide with the vertical and horizontal. |
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Thu Jul 18 20:20:52 2013, gautam, Configuration, endtable upgrade, First mirror glued to PZT and mounted in modified mounts
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Yesterday, I mounted the first PZT in one of the modified mounts, and then glued a 2-inch Y2 mirror on it using |
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Thu Jul 18 21:12:58 2013, gautam, Configuration, endtable upgrade, AI Board-D000186-All channels modified
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I carried some further modifications and tests to the AI Board. Details and observations here:
I switched out the resistors for all the remaining 7 channels, using the same substitutions as detailed here.
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Thu Jul 18 23:34:40 2013, gautam, Configuration, endtable upgrade, Coarse adjustment of PZT axes orientation in mount
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I have managed to orient the PZT in the mount such that its axes are approximately aligned with the vertical and
the horizontal.
In the process, I discovered that the 4 screws on the back face of the PZT correspond to the location of the piezoelectric stacks beneath the tip-tilt |
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Fri Jul 19 22:51:40 2013, gautam, Configuration, endtable upgrade, Second mirror glued to PZT and mounted
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I mounted the second PZT in a modified mount, and then glued a 1-inch Y2 mirror on |
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Fri Jul 19 23:35:31 2013, gautam, Configuration, endtable upgrade, Preliminary Calibration of PZT
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I recalibrated the QPD today as I had shifted its position a little. I then identified the linear range of the QPD
and performed a preliminary calibration of the Piezo tip-tilt within this range.
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Mon Jul 22 17:17:30 2013, annalisa, Update, endtable upgrade, End table picture
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Tue Jul 23 00:51:46 2013, Koji, Update, endtable upgrade, End table picture
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The spot on the IPANG QPD was checked. The spot is higher than the center and South side of the lens.
Some photos are found below.
The spot on the IPANG steering mirrors in the ETMY chamber was also checked. |
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Tue Jul 23 19:37:08 2013, Annalisa, Update, endtable upgrade, End table picture
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Quote:
The spot on the IPANG QPD was checked. The spot is higher than the center and South side of the lens. |
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Tue Jul 23 20:41:40 2013, gautam, Configuration, endtable upgrade, Full range calibration and installation of PZT-mounted mirrors
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Given that the green beam is to be used as the reference during the vent,
it was decided to first test the PZT mounted mirrors at the X-endtable rather than the Y-endtable as originally planned. Yesterday, I prepared a second
PZT mounted mirror, completed the full range calibration, and with Manasa, installed the mirrors on the X-endtable as mentioned in this |
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Sun Jul 28 19:39:04 2013, Annalisa, Update, endtable upgrade, Picture
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| Yend table picture updated on the wiki page |
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Mon Jul 29 13:39:25 2013, gautam, Configuration, endtable upgrade, PZT Driver Board-further changes
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I have updated the schematic of the D980323 PZT driver boards to reflect the changes |
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Mon Jul 29 21:57:45 2013, gautam, Configuration, endtable upgrade, Hardware installed at 1X9
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The following hardware
has been installed on rack 1X9;
KEPCO high voltage power supply |
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Tue Jul 30 19:40:47 2013, gautam, Configuration, endtable upgrade, DAC-PZT Driver Board Output Signal Chain Tested
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[Alex, Gautam]
The signal chain from the DAC output to the output of the PZT driver |
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Tue Jul 30 19:44:05 2013, gautam, Configuration, endtable upgrade, Second mirror glued to PZT and mounted
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I have glued a fourth mirror to a PZT (using superglue) and inserted
it into a modified mount. This is to be used together with the 1-inch Laseroptik mirror I had glued a couple of weeks back at the Y-endtable. |
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Mon Aug 5 18:48:44 2013, gautam, Configuration, endtable upgrade, Full range calibration of PZT mounted mirrors for Y-endtable
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I had prepared two more PZT mounted mirrors for the Y-end some time back. These are:
A 2-inch CVI mirror (45 degree, HR and AR for 532nm, was originally
one of the steering mirrors at the X-endtable, and was removed while switching those out for the PZT mounted mirrrors).
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Mon Dec 9 11:44:08 2013, Steve, Update, endtable upgrade, ETMY optable got new beam dump
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| Aluminum shield replaced by razor beam dump. |
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Mon May 12 14:42:25 2014, steve, Update, endtable upgrade, optical table enclosure wall proposal and table at ETMY
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Quote:
Sanwiched wall as shown: 1" clear acrylic, 2 layers of 0.004" thick "window tint", 1 layer of 0.007" |
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Fri Sep 11 10:56:47 2015, Steve, Update, endtable upgrade, ETMY optical table feedthrough
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The ETMY enclosure feedthrough - north is installed. The sealing material is hard to work with.
The upper empty blocks will be replaced by something soft to make changing cables easy.
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Tue Sep 15 16:49:08 2015, Steve, Update, endtable upgrade, ETMY optical table feedthrough
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ETMY optical table enclosure feedthrough- south is in. Now it is time to see how air tightness increases performance.
Quote:
The ETMY enclosure feedthrough |
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Thu Sep 17 02:22:53 2015, Steve, Update, endtable upgrade, ETMY optical table feedthrough
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I doubt we'll see any effect until we carefully seal the holes. If there's 1 hole in your boat it still sinks.
Quote:
ETMY optical table enclosure |
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Tue Dec 22 16:39:42 2015, Steve, Update, endtable upgrade, ETMY optical table enclosure
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I think there should be a scientifically based aveluation of the ETMY enclosure so we can make the ETMX better.
Meanwhile I'm counting pieces to move on with the south end table cover.
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Thu Mar 10 16:29:32 2016, gautam, Update, endtable upgrade, Inventory check
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I did a quick sweep of the lab to find out what hardware has already been acquired for the X-end table upgrade. The attached PDF is an inventory check
in the spirit of this elog.
Some things we have to decide: |