 Thu Nov 21 10:24:50 2013, Koji, Update, SUS, beam dumps
|
| You don't need the fourth glass piece on the diamond beam dump. |
|
Mon Jan 30 18:08:56 2023, Paco, Summary, BHD, c1cal DAQ error 0x2000
|
[JC, Paco]
I tried restarting all models this afternoon to see if the DC error 0x2000 on c1cal model cleared (currently no frame data is being written from
c1cal). By running ./restartAllModels.sh on the scripts/cds/ folder, and then BURT restoring, but unfortunately this didn't work. I also tried restarting |
Wed Mar 17 11:57:54 2021, Paco, Anchal, Update, SUS, Tested New Input Matrix for MC1 
|
[Paco, Anchal]
Paco accidentally clicked on C1:SUS-MC1_UL_TO_COIL_SW_1_1 (MC1 POS to UL Coil Switch) and clicked it back on. We didn't see any loss of lock
or anything significant on the large monitor on left. |
|
Fri Sep 7 09:37:20 2012, Steve, Update, Cameras, baffle plate for SOS
|
Quote:
The alignment of the pick-off mirror near ETMX is done. Everything turned out to be easy once we realized that there is no sense getting |
|
Wed Sep 12 17:02:00 2012, Steve, Update, Cameras, baffle plate hole getting larger
|
Quote:
|
|
Thu Nov 21 09:56:15 2013, Steve, Update, SUS, green glass beam dumps
|
Green welding glass is used in these Koji
designed dumps (D1102375)
We have 10 pieces of hexagonal dumps for 5.5" high beam They require 1 5/8" space. Atm1 |
|
Mon Jan 27 21:35:06 2020, Yehonathan, Update, PSL, Ringdown measurements
|
Zeroth order IMC ringdown setup
Following Gautam's IMC ringdown setup, I took the
REFL PD form the PMC ringdown experiment and installed it in the IMC REFL path blocking WFS2 (Attachment 1). |
|
Wed Oct 7 16:56:23 2020, anchal, Summary, ALS, ALS noise budget update - Updated AUX PDH Loop values
|
AUX PDH Loop update
I used D1400293 to get the latest logged details about
the universal PDH box used to lock the green laser at X end. The uPDH_X_boost.fil file present there was used to obtain the control model for this box.
See attachment one for the code used. Since there is a variable gain stage in the box, I tuned the gain of the filter model F_AUX in ALS_controls.yml |
|
Tue Jan 12 03:03:55 2016, ericq, Update, LSC, Frequently making noise
|
Gautam will soon follow up with detailed analysis, but here is a brief summary of some of our activities and findings.
Two Marconis were beat together in various ways, we figured the noise added by turning on external modulation didn't make us happy.
I
locked the AUX X laser to the PSL via PZT. I'm more likely to believe we're seeing real broadband laser noise in this configuration; locking the |
|
Sat Jan 9 00:39:15 2016, gautam, Update, LSC, AUX Y Freq Noise re-measured
|
Quote:
With the Y end laser,
I was able to lock the PLL with a lower actuation range (1.6MHz/V), and with the PSL in both the free-running and MCL locked configurations. |
|
Mon Jan 11 19:01:56 2016, gautam, Update, LSC, PLL Marconi Investigation 6x
|
EDIT 01/12/2016 6PM: I've updated the plots of the in-loop spectra such that they
are calibrated throughout the entire domain now. I did so by inferring the closed-loop transfer function
(G/(1-G)) from the measured open-loop transfer function (G), and then fitting the inferred TF using vectfit4 (2 poles). The spectra were calibrated |
|
Tue Jan 12 19:38:31 2016, gautam, Update, LSC, Frequently making noise
|
EDITS 15Jan:
Schematic of test setup added (Attachment #5). Note that the UGF measurements were made with the
LPF and gain on the 'wrong' SR560, in a way defeating the purpose of having 2 SR560s in the setup. I only realised this after taking the measuements. |
|
Wed Apr 1 00:51:41 2020, gautam, Update, Wiener, Slightly improved MCL FF
|
Summary:
Retraining the MCL filters resulted in a slight improvement in the performance. Compared to no FF, the RMS in the 0.5-5 Hz range
is reduced by approximately a factor of 3. |
|
Thu Oct 8 11:59:52 2020, rana, Summary, ALS, ALS noise budget update - Updated AUX PDH Loop values
|
For all the loops where we drive the NPRO PZT, there is some notch/resonance feature due to the PZT mechanical resonance. In the IMC loop this limits
the PZT/EOM crossove to be less than 25 kHz. I don't have a model for this, btu it should be included.
If you hunt through the elogs, people have measured the TF of ALS NPRO PZT to phase/frequency. Probably there's also a measured ALS PDH loop |
|
Tue Jan 24 16:12:07 2023, rana, Summary, BHD, FPMI displacement noise with 60 Hz harmonics side lobes
|
1) do a comparison with the whtiening before the ADC on/off. This will tell us if it is pickup before the whtiening filter or not.
2) If there are ground loops made by 44 MHz setup, we want to draw a simple diagram which includes which sides are grounded and which have transformers.
How about make a drawing to bring to the group meeting tomorrow? IN the lab we have these coaxial BALUNs for making a 1:1 transformer coupling. |
|
Mon Jul 26 10:04:24 2010, steve, Update, General, Initial Crane Inspection reveals flaws: wiring, oil and imbalance
|
Quote:
The guy from KroneCrane (sp?) came today and started the crane inspection on the X End Crane. There were issues with |
|
Wed Jul 28 16:42:21 2010, steve, Update, General, Crane gear box cheched
|
Quote:
|
|
Fri Aug 6 17:47:36 2010, steve, Summary, General, cranes load tested at 1998 lbs
|
Quote:
|
|
Tue Jan 24 11:21:59 2023, yuta, Summary, BHD, FPMI displacement noise with 60 Hz harmonics side lobes
|
Just to show how bad 60 Hz noise is, I compared FPMI displacement noise with pre-BH44 era (measured on Jan 13, 40m/17400).
Blue curve in Attachment #1 is the sensitivity with FPMI locked with RF in pre-BH44 era, and pink curves are that measured today
(C1:CAL channels are currently unavailable due to 0x2000 appeared after running restatAllModels.sh). |
|
Thu Jan 30 15:24:10 2020, ?, Update, General, delay line frequency discriminator for PM
|
yes, its fine to use this with a level 3 or level 7 mixer; let's see
some PM transfer functions !
Quote:
|
|
Mon Dec 21 07:30:58 2009, ???, Update, ASS, OAF Model update and build instructions
|
What does OAF stand for? The entry doesn't say that. Also the acronym is not in the abbreviation page of the wiki.
Can anyone please explain that? |
 Tue Jun 7 17:21:13 2016, Aakash, Update, General, SURF 2016
|
Hi!
I am Aakash Patil. I will be working at the 40m lab as a SURF student with Gautam Venugopalan on enclosures for seismometers to shield them from
thermal and magnetic fluctuations. This week I will be working on the development of hardware for four probe measurement along with a constant current |
|
Thu Jun 9 09:57:06 2016, Aakash, Update, General, Seismometer Enclosure Development
|
Me and Gautam yesterday opened the tilt-free seismometer enclosure to see if we could use the thermocouples and
other things
previously used by Megan. But we are planning to get new four-wire RTDs for our work.
For the next day or two, I will be trying to set up Acromag Busworks
terminal so that the data logging during
this enclosure development experiment becomes perfect and easy. Johannes has sent me the wiki page URL for the |
|
Thu Jun 9 18:54:40 2016, Aakash, Update, General, About Acromag | SURF 2016
|
Today I tried to setup Acromag Busworks card. I was able to calibrate and test it over USB but I couldn't test it over ethernet. I'll utilize
a few hours tomorrow to test it over ethernet and see if I can make it work. I have also found a few RTDs which I want to use for temperature sensing via
four probe method. So, tomorrow I'll get these RTD details revived by Gautam and Steve. |
|
Mon Jun 13 19:30:58 2016, Aakash, Update, General, EPICS Installation | SURF 2016
|
About acquiring data: Initially I couldn't start with proper Acromag setup as the Raspberry pi had a faulty SD card slot. Then Gautam gave me a working
pi on which I tried to install EPICS. I spent quite a time today but couldn't setup acromag over ethernet. But, it would be great if we have
a USB DAQ card. I have found a good one here |
|
Tue Jun 28 22:54:43 2016, Aakash, Update, General, Seismometer Enclosure Development | SURF 2016
|
The existing enclosure for seismometer at LIGO 40m lab is a cylindrical stainless steel can placed upside down over the seismometer. It has more empty
space between the seismometer and the internal surface of enclosure which is not desirable(I'll quantitatively elaborate this statement once my temperature
measuring setup is ready). |
|
Wed Jun 29 00:09:36 2016, Aakash, Update, General, Things from past | SURF 2016
|
| I have taken out the heaters and temperature sensors from the enclosure which was made by Megan last summer. Soon I will test and configure those heaters. |
|
Fri Jul 1 01:52:54 2016, Aakash, Update, General, Seismometer Enclosure Development | SURF 2016
|
I have transferred most of the temperature measurement stuff from the front area to seismometer at the end of Y-arm. While arranging the components
I have taken all care that they will not interfere with existing system. Also, I have temporarily taken a monitor from the front area to the area near
same seismometer as I couldn't talk to Rpi via ssh. For next twelve hours, I am now recording temperature inside as well as outside the seismometer |
|
Wed Jul 6 16:40:09 2016, Aakash, Update, General, Seismometer Enclosure Development | SURF 2016
|
I am using AD592CNZ temperature transducer ICs for measuring temperature inside as well as outside the enclosure. It is a current
output IC which outputs current proportional to temperature. As mentioned in the data sheet of AD592, I am using the following two schematics:
|
|
Fri Jul 8 13:01:23 2016, Aakash, Update, General, Acromag is talking ! | SURF 2016
|
Acromag is talking now, after few changes to the original EPICS configuration and cross compile configuration. Modbus config files also were changed
and compiled again to run it on linux-arm architecture. I have made use of pyModbus for the final work and I am planning to use the same for grabbing channels.
Though I am unable to grab channel data right now, I am able to communicate to it over ethernet and send and receive data. |
|
Fri Jul 15 17:44:37 2016, Aakash, Summary, General, Acromag Setup | SURF2016
|
Aidan has described the physical connections and initial setup here : https://nodus.ligo.caltech.edu:30889/ATFWiki/doku.php?id=main:resources:computing:acromag#recovering_from_a_terminal_power_communication_outage
.
Since I used a Raspberry Pi(domenica.martian) for communicating to Acromag(acroey.martian) card, I had to recompile everything for linux-arm |
|
Mon Jul 18 05:05:05 2016, Aakash, Update, General, Heater for Seismometer Enclosure | SURF 2016
|
I took off the silicon rubber heaters which were used by a SURF last year for heating the enclosure. The heater data sheet has mentioned the power dentsities,
but I doubted the values. So I wanted to measure the actual power density by these heaters. I think the rubber heaters are broken somewhere within, the
surface is not heated evenly. Although I don't have a good quantative reason to use, I was thinking to use a thermoelectric cooling module for the |
|
Thu Jul 21 05:22:26 2016, Aakash, Update, General, Temperature measurements across the enclosure | SURF 2016
|
I have measured the transfer function of temperature fluctuations inside the enclosure to that of the temperature fluctuations outside. The transfer
function has been estimated by using 'tfestimate' which is library function in Matlab and which estimates the transfer function based on Welch's
method. The attached plots shows the transfer function of the temperature inside the enclosure to that of outside temperature. |
|
Thu Jul 21 21:38:44 2016, Aakash, Update, General, Temperature measurements across the enclosure | SURF 2016
|
| I have made the changes as suggested by Gautam. |
|
Fri Jul 22 05:20:26 2016, Aakash, Update, General, Temperature measurements across the enclosure | SURF 2016
|
| Please find the new attached plots and the new script. |
|
Fri Jul 29 03:44:04 2016, Aakash, Summary, , About Acromag | SURF 2016
|
I tried to recompile the modbusApp binary for linux-arm acrhitecture since I suspected someting wrong with it. But still the problem persists; I can
connect to acromag but cannot access the channels. I have also reconfigured new acromag bus works terminal XT 1221-000 and I want to test if I could access
its channels. My target is to complete this acromag setup work before sunday morning so that I can focus towards having some useful results for my presentation. |
|
Mon Aug 1 18:50:29 2016, Aakash, Update, General, Acromag Setup | SURF2016 7x
|
There were many unknown and unsolved problems with using modbusApp for linux-arm architecture. So I tried to install the necessary files to setup Acromag
Busworks card 1221-000 on Zita(192.168.113.217), which is a linux-x86_64 machine on the martian network. After installing a few dependencies and seting
up few symbolic links for some libraries, everything is successfully configured. Initially I was unable to run myiocconfig.cmd file(as mentioned by Aiden |
|
Wed Aug 3 15:35:19 2016, Aakash, Update, General, Acromag Setup | SURF2016
|
Lydia helped me to troubleshoot the Accromag connection problems which I was facing previously. If power goes off/turned off manually, the ethernet
cable has to be pulled out and put back again until only a non-blinking green light is observed. I was foolish enough that I did not use secure power connections.
About the random symbol, a code block was not closed in the other supporting file which was being called in the main program. There are still some port |
|
Sat Aug 28 08:17:51 2010, Aberto, Update, Electronics, FSS Frequency Generation Box under test
|
| I've taken the FSS frequency generation box out of the 1Y1 rack. It's sitting on one of the electronics benches. I'm measuring its phase noise. |
|
Mon Dec 3 19:44:58 2007, Accelerometers on new mounts, Configuration, PEM, Andrey
|
I (Andrey) continued today working with new accelerometer mounting. (see entry #151 about my Friday work).
|
|
Sat Jul 26 15:09:57 2008, Aidan, Update, Computers, Reboot of op440m
|
I was reviewing the PSL Overview screen this afternoon and op440m completely froze when I center-clicked on the REF CAVITY TRANSMISSION indicator. It was
unresponsive to any keyboard or mouse control. The moon button had no effect to shut the machine down.
|
|
Mon Dec 29 18:01:07 2008, Aidan, Update, Auxiliary locking, Updated 40m Upgrade Document T080074-00-R
|
Added a paragraph to the 40m Upgrade document describing the fiber stabilization and frequency doubling proposed for auxiliary locking.
|
|
Fri Jun 19 13:39:29 2009, Aidan, Update, General, Upper limit measurement of the scatter from the eLIGO beam dumps.
|
I measured the scatter from the eLIGO beam dumps as best I could. The experiment |
|
Thu Jul 23 07:34:45 2009, Aidan, Update, CDS, Added C2 MEDM screens to 40m SVN.
|
See Adhikari eLOG entry: http://nodus.ligo.caltech.edu:8080/AdhikariLab/194 |
|
Mon Apr 12 17:48:32 2010, Aidan, Update, Computer Scripts / Programs, elog restarted
|
| The elog crashed when I was uploading a photo just now. I logged into nodus and restarted it. |
|
Mon Apr 12 19:50:30 2010, Aidan, Summary, Green Locking, Temperature sweep of the Lightwave: df/dT = 2.8GHz/K
|
The beams from the Innolight and Lightwave NPROs were both incident on a 1GHZ New Focus PD. Mott and I swept the temperature of the Lightwave and tracked
the change in frequency of the beatnote between the two. The Innolight temperature was set to 39.61C although the actual temperature was reported to be
39.62C. |
|
Mon Apr 19 11:31:04 2010, Aidan, Update, Green Locking, 1W NPRO output profile
|
Quote:
Koji asked me to take a profile of the output of the 1W NPRO that will be used for green locking. I used the razor-scan method, plotting |
|
Mon Apr 19 16:27:13 2010, Aidan, Update, Green Locking, Raicol crystals arrived and we investigated them
|
Jenne, Koji and I opened up the package from Raicol and examined the crystals under the microscope. The results were mixed and are summarized below.
There are quite a few scratches and there is residue on some of the polished sides. There is a large chip in one and there appear to be gaps or bands in
the AR coatings on the sides. |
|
Tue Apr 20 11:14:31 2010, Aidan, Update, Green Locking, Raicol crystals arrived and we investigated them
|
Here is Crystal 724 polished side 2 with
all photos along the length stitched together |
|
Tue May 11 14:39:17 2010, Aidan, Update, Green Locking, Green Laser Beam Profile
|
Here's a photo of the set-up used. The beam profile is measured relative to the f=-100mm lens. |