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  3843   Tue Nov 2 00:17:01 2010 SureshConfigurationLockingTemporary changes to the Video Mux

Fiber coupling 1064 nm light at the end of X arm

This is 'work in progress'.  The attempt is to bring a few milliwatts of the 1064 nm light from the NPRO at the end of the South(X) Arm to the PSL table through an single mode optical fiber.  This would enable us to tune the two NPRO's to be less than 15 MHz apart by looking at their beat frequency before doubling.  Because we have a 1GHz bandwidth PD at 1064 nm, while the photodiode for green has a BW of about 30MHz.

A PBS (P-type) cube has been introduced into the beam of the X arm NPRO  (between the lamda/2 plate and the input lens of the doubling crystal).  By rotating the face of the PBS slightly away from normal incidence, I have diverted away 1.5mW of the 1064 light for coupling into the fiber. The beam has shifted slightly because of this and the green beam from the south arm has to be realigned to reach the PSL table.

A single mode fiber (Thorlabs SM980-5.8-125),  which was already laid half way, has been extended all the way to the PSL table. It runs along the  South arm in the cable tray. 

A pair of mirrors have been arranged in a zig-zag to steer the beam into a fiber coupler.  There was some hope that this coupler had been aligned at some point in the past and that attaching a fiber might result in some transmission.  But this is not the case and fiber coupler needs to be readjusted.

In order to see the light transmitted through the fiber, a camera has been set up on the PSL table.  Its output has been routed into the 'Ref Cavity reflected' video signal.  A video cable running from the ETMX to the Video-MUX used to be connected to the input channel 9 of the Video MUX.  This has now been shifted to output channel 25 of the MUX and disconnected from the camera at the ETMX.   The 'Ref Cav Refl.' video signal has been routed to the output channel 25.  The camera looking at the fiber output can now be seen on a local monitor at the end of the X arm and on the video monitor in the control room.

With the fiber disconnected, the 1064 nm beam was steered into the fiber coupler and its transmission maximised by observing  with an IR viewer.  The fiber was then connected and then the transmission at the PSL table was sought.  There was no transmission seen after a searching around this region for a few mins.

The plan is to purchase a Visual fault locator which would enable us to quickly get a rough alignment of the fiber coupler. A local vendor is listed as a distributor for this product from JDSU.  Contact info:

DuVac Electronics (EDGE)
Tel: 626-796-3291
Email: jack@duvac.com
1759 E Colorado Blvd
Pasadena, CA 91106

 

  3853   Wed Nov 3 15:13:55 2010 josephbUpdateCDSTemporary RFM slow read work around

Problem:

Each RFM read in the c1mcs model is adding ~7 microseconds to the cycle time.  Adding too many pushes it over the 62 microsecond limit.

RFM writes do not have this problem.

Temporary Solution:

The fastest fix was to create a new front end model, called c1rfm, which does nothing but read in the MC1, MC2, MC3 PIT and YAW signals from the c1ioo machine, and then passes them along to the c1mcs model via shared memory, which is fast.

This means the data being sent is 2 cycles slow, one to go over the RFM, and one to go over shared memory.  It is running at 16384 cycles/second, so it shouldn't have much impact at the frequencies we use those channels for.

MC_L is still being sent directly to the c1mcs front end code via RFM.

Current Status:

The c1mcs model is running at  30-33 microseconds for CPU time.

The c1rfm model is running at 45-47 microseconds for CPU time.

All 7 channels, MC_L, MC1_PIT, MC1_YAW, MC2_PIT, MC2_YAW, MC3_PIT, MC3_YAW are responding.

The c1rfm model was added to the /diskless/root/etc/rtsystab file on the fb machine so that it automatically starts on the reboot of c1sus.

The USR and CPU time channels for c1rfm were added to the MCS_SLOW.ini file in /opt/rtcds/caltech/c1/chans/daq/ so that the framebuilder records them, namely:

[C1:FEC-38_USR_TIME]
[C1:FEC-38_CPU_METER]

The framebuilder was restarted to take these new channels into account.

Future:

Finish implementing and debugging the "round robin" RFM reader so as to not require a seperate model to be doing RFM reads in parallel.

Look into improving read speed by either merging timestamps and data into a single  or reading time stamp once every tenth or hundreth cycle, although this at best provides a factor of 2 improvement.

Check to see if RFM card being on the IO chassis or directly in the computer chassis makes a difference.

Get Alex and Rolf to improve RFM read speed.

  13645   Wed Feb 21 00:04:27 2018 gautamUpdateElectronicsTemporary RF power monitor setup

I made a voltage divider using a 20.47kohm and 1.07kohm (both values measured with a DMM). The whole thing is packaged inside a Pomona box I found lying around on the Electronics bench. I have hooked it up to the ALSY_I channel and will leave it so overnight. The INMON of this channel isn't DQed, but for this test, the 16Hz EPICS data will suffice. I've locked the EX laser to the arm, enabled slow temperature servo to allow overnight lock (hopefully) and disabled LSC mode (as locking the arm to the MC tends to break the green lock)

To convert the INMON counts to RF power, I will use (based on my earlier calibration of this monitor channel, see DCC document for the demod chassis).

\mathrm{P_{RF}} (\mathrm{dBm}) = \frac{19.13 \times \frac{cts}{1638.4} - 10.23}{0.12}


1AM update: Attachment #1 shows that the RF amplitude has been relatively stable (less than 10% of nominal value variation) over the course of the last hour or so. Even though there is some low frequency drift over timescales of ~20mins, no evidence of the wild ~20dB amplitude changes I saw last week. The signs are encouraging...

overnight update: See Attachment #2 - looking at the past 11 hours of second trend data during which the arm stayed locked, there actually seems to have been more significant variation in the beatnote amplitude. Swings of up to 6dBm are seen on a ~20min timescale, while there is also some longer term drift over 12 hours by a couple of dBm. There is probably a systematic error in the Y-axis, as I measured the RF power at the input of the power splitter at the LSC rack to be ~3dBm, so I expect something closer to 0dBm to be the LO input power which is what I am monitoring. So further debugging is required - I think I'll start by aligning the X fiber coupled beam to one of the fiber's special axes.

Attachment 1: RFbeatAmp.png
RFbeatAmp.png
Attachment 2: BeatMouthX_RFAM_20180221.pdf
BeatMouthX_RFAM_20180221.pdf
  3498   Tue Aug 31 16:42:26 2010 josephbUpdateCDSTemporarily reverting to CDS revision 2005

Apparently updating to the latest revision of the RCG has some issues with diaggui and awgtpman.  Alex had to do some recompiling up at Hanford which apparently took him some time.  He'll be coming by tomorrow to try to bring those codes to the front end machines.

As a temporary fix, until Alex gets here tomorrow, we're reverting to the 2005 revision in the svn of the cds code.  I'm placing it in the location it is supposed to go in the new advLIGO scheme, which is /opt/rtcds/caltech/c1/core/, which is where Keith had it at LLO.  Once we get the new codes working, we will do an svn update on that location and migrate our work to that install location, at which point I'll remove the old /cvs/cds/caltech/cds/advLigoRTS/ location.

  4250   Fri Feb 4 13:45:25 2011 josephbUpdateComputersTemporarily removed cronjob for rsync.backup
<p>I removed the rsync backup from nodus' crontab temporarily so as to not have multiple backup jobs running.&nbsp; The job I started from yesterday was still running.&nbsp; Hopefully the backup will finish by Monday.</p>
<p>The line I removed was:</p>
<p>0 5 * * * /opt/rtcds/caltech/c1/scripts/backup/rsync.backup</p>
<table align="left" width="786" cellspacing="1" cellpadding="1" border="2">
    <tbody>
        <tr>
            <td><span style="font-size: larger;">MC damp</span></td>
            <td><span style="font-size: larger;">dataviewer</span></td>
            <td><span style="font-size: larger;">diaggui</span></td>
            <td><span style="font-size: larger;">AWG</span></td>
            <td><span style="font-size: larger;">c1lsc</span></td>
            <td><span style="font-size: larger;">c1ioo</span></td>
            <td><span style="font-size: larger;">c1sus</span></td>
            <td><span style="font-size: larger;">c1iscex</span></td>
            <td><span style="font-size: larger;">c1iscex</span></td>
            <td><span style="font-size: larger;">RFM</span></td>
            <td><span style="">The Dolphins</span></td>
            <td><span style="font-size: larger;">Sim.Plant</span></td>
            <td><span style="font-size: larger;">Frame builder</span></td>
            <td><span style="font-size: larger;">TDS</span></td>
            <td><span style="font-size: larger;">Cabling</span></td>
        </tr>
        <tr>
            <td bgcolor="blue"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="green"><span style="font-size: larger;">&nbsp;</span></td>
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            <td bgcolor="yellow"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="orange"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="yellow"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="blue"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="yellow"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="yellow"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="blue"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="blue"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="red"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="blue"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="orange"><span style="font-size: larger;">&nbsp;</span></td>
            <td bgcolor="orange"><span style="font-size: larger;">&nbsp;</span></td>
        </tr>
    </tbody>
</table>
  4252   Fri Feb 4 18:58:19 2011 ranaUpdateComputersTemporarily removed cronjob for rsync.backup

Quote:

I removed the rsync backup from nodus' crontab temporarily so as to not have multiple backup jobs running.  The job I started from yesterday was still running.  Hopefully the backup will finish by Monday.

The line I removed was:

0 5 * * * /opt/rtcds/caltech/c1/scripts/backup/rsync.backup

Actually, this is not true. Joe actually killed the currently running backup and set it to start tomorrow morning at 6AM. Its taking forever since its not an incremental backup but a new one due to the change in the setup.

  4256   Mon Feb 7 10:37:28 2011 josephbUpdateComputersTemporarily removed cronjob for rsync.backup

The backup appears to have finished on nodus, and I've put the rsync job back in the crontab.

Quote:

I removed the rsync backup from nodus' crontab temporarily so as to not have multiple backup jobs running.  The job I started from yesterday was still running.  Hopefully the backup will finish by Monday.

The line I removed was:

0 5 * * * /opt/rtcds/caltech/c1/scripts/backup/rsync.backup

  2793   Mon Apr 12 19:50:30 2010 AidanSummaryGreen LockingTemperature 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.

Freq. vs temperature is plotted below in the attached PDF. The slope is 2.8GHz/K.

The data is in the attached MATLAB file.

Attachment 1: LightWave_temp_sweep.pdf
LightWave_temp_sweep.pdf
Attachment 2: LightWave_Temp.m
% plot the data from the Lightwave Temperature sweep

% Lightwave temperature

LWTemp = [0.2744
    0.2753
    .2767
    .2780
    .2794
    .2808
... 67 more lines ...
  2794   Mon Apr 12 20:48:51 2010 Aidan, MottSummaryGreen LockingTemperature sweep of the Innolight: df/dT ~ 3.3GHz/K

Quote:

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.

Freq. vs temperature is plotted below in the attached PDF. The slope is 2.8GHz/K.

The data is in the attached MATLAB file.

 Same thing for the Innolight Mephisto.

Not unexpected values with dn/dT around 11E-6 K^-1 and coefficient of thermal expansion = 8E-6 K^-1 and a laser resonator length of order 10cm.

Attachment 1: Innolight_temp_sweep.pdf
Innolight_temp_sweep.pdf
Attachment 2: Innolight_Temp.m
% plot the data from the Innolight Temperature sweep

% Innolight temperature

InnTemp = [0.60
    .59
    .56
    .52
    .65] + 39;

... 25 more lines ...
  2797   Tue Apr 13 12:39:51 2010 Aidan, MottSummaryGreen LockingTemperature sweep of the Innolight: df/dT ~ 3.3GHz/K

Please put those numbers onto wiki somewhere at the green page or laser characterization page.

Quote:

Quote:

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.

Freq. vs temperature is plotted below in the attached PDF. The slope is 2.8GHz/K.

The data is in the attached MATLAB file.

 Same thing for the Innolight Mephisto.

Not unexpected values with dn/dT around 11E-6 K^-1 and coefficient of thermal expansion = 8E-6 K^-1 and a laser resonator length of order 10cm.

 

  5228   Sun Aug 14 04:12:37 2011 JennyUpdatePSLTemperature steps and slow actuator railing

Below are some plots from dataviewer of temperature-step data taken over the past 32 hours. (They show minute trends). I am looking at the thermal coupling from the can surrounding the reference cavity on the PSL table to the cavity itself, and trying to measure the cavity temperature response via the control signal sent to heat the NPRO laser, which is locked to the cavity.

Picture_6.png

Picture_7.png

  • Top left: out-of-loop temperature sensor on can surrounding ref cav (RCTEMP)
  • Top right: control signal sent to slow drive of laser (laser heater), which is supposed to follow the cavity temperature (TMP_OUTPUT)
  • Bottom left: in-loop can temperature sensors (MINCOMEAS)
  • Bottom right: room temperature reading (RMTEMP)

 

I stepped the temperature set point from 35 to 36 deg. C for the can at 12:30am last night. Then I waited to see the cavity temperature change and the slow actuator (laser heater: TMP_OUTPUT) follow that change.

I was a bit worried about the oscillations that were occuring in the TMP_OUTPUT signal even long after this temperature step was made, but I figured that they were simply room-temperature changes propagating into the cavity, since they seemed to have a similar pattern to the room-temperature variations, and since it is clear that the out-of-loop temperature sensor on the can (RCTEMP) experiences variations, even when the in-loop sensors are recording no variation.

At 8:46pm tonight I stepped the temperature down 2 degrees to 34 deg. C. The step had a clear effect on TMP_OUTPUT. The voltage to the heater dropped and eventually railed at its lowest output. I'm worried that the loop is unstable, although I haven't ruled out other possibilities, such as that a 2 deg. C temperature step is too large for the loop. I will investigate further in the morning.

  5230   Sun Aug 14 15:37:39 2011 JennyUpdatePSLTemperature steps and slow actuator railing

Quote:

Below are some plots from dataviewer of temperature-step data taken over the past 32 hours. (They show minute trends). I am looking at the thermal coupling from the can surrounding the reference cavity on the PSL table to the cavity itself, and trying to measure the cavity temperature response via the control signal sent to heat the NPRO laser, which is locked to the cavity.

Picture_6.png

Picture_7.png

  • Top left: out-of-loop temperature sensor on can surrounding ref cav (RCTEMP)
  • Top right: control signal sent to slow drive of laser (laser heater), which is supposed to follow the cavity temperature (TMP_OUTPUT)
  • Bottom left: in-loop can temperature sensors (MINCOMEAS)
  • Bottom right: room temperature reading (RMTEMP)

 

I stepped the temperature set point from 35 to 36 deg. C for the can at 12:30am last night. Then I waited to see the cavity temperature change and the slow actuator (laser heater: TMP_OUTPUT) follow that change.

I was a bit worried about the oscillations that were occuring in the TMP_OUTPUT signal even long after this temperature step was made, but I figured that they were simply room-temperature changes propagating into the cavity, since they seemed to have a similar pattern to the room-temperature variations, and since it is clear that the out-of-loop temperature sensor on the can (RCTEMP) experiences variations, even when the in-loop sensors are recording no variation.

At 8:46pm tonight I stepped the temperature down 2 degrees to 34 deg. C. The step had a clear effect on TMP_OUTPUT. The voltage to the heater dropped and eventually railed at its lowest output. I'm worried that the loop is unstable, although I haven't ruled out other possibilities, such as that a 2 deg. C temperature step is too large for the loop. I will investigate further in the morning.

 The lock was lost when I came in around noon today to check on it. The slow actuator was still railing.

1) I got lock back for a few minutes, by varying the laser temperature set point manually. TMP_OUTPUT was still reading -30000 cts (minimum allowed) and the transmission was not as high as it had been.

2) I toggled the second filter button off. The TMP_OUTPUT started rising up to ~2000 cts. I then toggled the second filter back on, and TMP_OUTPUT jumped the positive maximum number of counts allowed.

3) I lost the lock again. I turned off the digital output to the slow actuator.

4) I have so far failed at getting the lock back. My main problem is that when the BNC cable to the slow port is plugged in, even when I'm not sending anything to that port, it makes it so that changing the temperature set point manually has almost no effect on the transmission (it looks as though changing the setpoint is not actually changing the temperature, because the monitor shows the same higher order mode even when with +-degree temperature setpoint changes).

  15272   Thu Mar 12 16:13:16 2020 gautamUpdatePSLTemperature sensors connected to Acromag

[jordan, gautam]

the long DB25 cable to connect the Acromag chassis to the temperature sensor interface box arrived. We laid it out today. This cable does the following:

  1. Supply the box with +/- 24 V DC from the chassis. The pin arrangement here is rather unfortunate (the +/-24 V DC and GND pins are in close proximity), so if you're not careful, you'll create a short as you plug this cable in (as we found out today). So the best practise is to power down the crate before connecting/disconnecting this cable. Jordan will label this accordingly tomorrow.
  2. Pipe the "TAMB" and "TCAV" signals, corresponding to temperature sensors mounted to the PSL table-top and reference cavity exterior respectively, to the Acromags. We found during some initial testing that the "TAMB" signal was reaching the DB25 connector on the Acromag chassis, but wasn't going to any ADC channel - this was rectified.

Both signals now show up in the EPICS channels, but are noisy - I suspect this is because the return pin of the Acromag is not shorted to ground (this is a problem I've seen on the bench before). We will rectify this tomorrow as well.

We took this opportunity to remvoe the bench supply and temporary Acromag crate (formerly known as c1psl2) from under the PSL table. While trying to find some space to store the bench supply, we came across a damaged Oscilloscope in the second "Electronics" cabinet along the Y-arm, see Attachment #1. 

After this work, I found that the IMC autolocker was reliably failing to run the mcup script at the stage where the FSS gains are ramped up to their final values. I was, however, able to smoothly transition to the low-noise locked state if I was manipulating the EPICS sliders by hand. So I added an extra 2 seconds of sleep time between the increasing of the VCO gain to the final value and the ramping of the FSS gains in the mcup script (where previously there was none). Now the autolocker performs reliably.

Attachment 1: P_20200317_153736_vHDR_On_2.jpg
P_20200317_153736_vHDR_On_2.jpg
  16338   Thu Sep 16 12:06:17 2021 TegaUpdateComputer Scripts / ProgramsTemperature sensors added to the summary pages

We can now view the minute trend of the temperature sensors under the PEM tab of the summary pages. See attachment 1 for an example of today's temperature readings. 

Attachment 1: TempPlot_2021-09-16_12.04.19PM.png
TempPlot_2021-09-16_12.04.19PM.png
  16214   Fri Jun 18 14:53:37 2021 AnchalSummaryPEMTemperature sensor network proposal

I propose we set up a temperature sensor network as described in attachment 1.

Here there are two types of units:

  • BASE-GATEWAY
    • Holds the processor to talk to the network through Modbus TCP/IP protocol.
    • This unit itself has a temperature sensor in it. It is powered by a power adaptor or PoE from the switch.
    • Each base unit can have at max 2 extended temperature probes ENV-TEMP.
  • ENV-TEMP
    • This is just a temperature probe with no other capabilities.
    • It is powered via PoE from the BASE-GATEWAY unit.

Proposal is

  • to put 2 ENV-TEMP sensors (#1 and #2) along the Y-arm at the end and midway. These are powered and read through a BASE-GATEWAY (#A) at the vertex. The BASE-GATEWAY (#A) will serve as temperature sensor for the vertex.
  • We put one ENV-TEMP(#3) at the X-end powered and read through by another BASE-GATEWAY (#B) at the midpoint of X-arm.
  • Both BASE-GATEWAY are connected by ethernet cables to the network switch. That's it.

These sensors can be configured over network by going to their assigned IP addresses. I'm not sure at the moment how to configure the dB files to get them to write on slow EPICS channels.

We will have an unused port on the BASE-GATEWAY (#B) which can be used to run another temperature sensor, maybe at an important rack, PSL table or somewhere else.

In future, if more sensors are required, there are expansion (network switch like) options for BASE-GATEWAY or daisy-chain options for the probes.



Edit Fri Jun 18 16:28:13 2021 :

See this [wiki page](https://wiki-40m.ligo.caltech.edu/Physical_Environment_Monitoring/Thermometers) for updated plan and final quote.

Attachment 1: 40mTempSensors.pdf
40mTempSensors.pdf
  2843   Mon Apr 26 11:14:04 2010 KojiUpdateGreen LockingTemperature scan for PPKTP

I scanned the temperature of the crystal oven on Friday night in order that we can find the optimal temperature of the crystal for SHG.

The optimal temperature for this crystal was found to be 36.2 deg.


The crystal is on the PSL table. The incident beam on the crystal is 27.0mW with the Newport power-meter configured for 1064nm.
The outgoing beam had 26.5mW.

The outgoing beam was filtered by Y1-45S to eliminate 1064nm. According to Mott's measurements, Y1-45S has 0.5% transmission for 1064nm, while 90% transmission for 532nm. This means I still had ~100uW after the Y1-45S. This is somewhat consistent with the offset seen in the power-meter reading.

First, I scanned the temperature from 28deg to 40deg with 1deg interval.The temperature was scaned by changing the set point on the temperature controller TC-200.The measurements were done with the temperature were running. So, the crystal may have been thermally non-equilibrium.

Later, I cut the heater output so that the temperature could be falling down slowly for the finer scan. The measurement was done from 38deg to 34deg with interval of 0.1deg with the temperature running.

I clearly see the brightness of the green increase at around 36 deg. The data also shows the peak centered at 36.2deg. We also find two lobes at 30deg and 42deg. I am not sure how significant they are.

Attachment 1: SHG_pow.png
SHG_pow.png
  6647   Wed May 16 14:06:49 2012 steveUpdateSUSTemperature rules

Guralp 1  is on the south side of IOO chamber

Attachment 1: temprules.png
temprules.png
  12317   Thu Jul 21 05:22:26 2016 AakashUpdateGeneralTemperature 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.

fig1.pdf

fig2.pdf

In order to determine a relation between temperature inside the enclosure to that of the outside temperature, I have calculated the mean squared coherence.  I have used Matlab's 'mscohere' library function which uses Welch's method to calculate the coherence. Attached plot shows the coherence between the temperature across the enclosure.

fig3.pdf

Also, I have attached the matlab script which I used for generating these plots.

script21jul2016.m

Attachment 1: script21jul2016.m
filename='2315on5july.dat';
data=importdata(filename);
%temperature data outside the enclosure on channel 2
data1=data(:,2); 
%temperature data inside the enclosure on channel 3
data2=data(:,3); 

%sampling frequency in Hz
fs=100; 
... 30 more lines ...
Attachment 2: fig1.pdf
fig1.pdf
Attachment 3: fig2.pdf
fig2.pdf
Attachment 4: fig3.pdf
fig3.pdf
  12323   Thu Jul 21 21:38:44 2016 AakashUpdateGeneralTemperature measurements across the enclosure | SURF 2016

I have made the changes as suggested by Gautam.

  12326   Fri Jul 22 05:20:26 2016 AakashUpdateGeneralTemperature measurements across the enclosure | SURF 2016

Please find the new attached plots and the new script.

Attachment 1: coherence.pdf
coherence.pdf
Attachment 2: transferfunc.pdf
transferfunc.pdf
Attachment 3: transferfuncdB.pdf
transferfuncdB.pdf
Attachment 4: script22jul2016.m
filename='2315on5july.dat';
data=importdata(filename);
%temperature data outside the enclosure on channel 2
data1=data(:,2); 
%temperature data inside the enclosure on channel 3
data2=data(:,3); 

%sampling frequency in Hz
fs=100; 
... 40 more lines ...
  4635   Thu May 5 13:12:06 2011 JenneUpdatePSLTemperature drift, trying to shield PMC with foil

eeek.  I've been running around all day, so this is an incomplete elog.  I'll fill in more stuff in the next hour or so, but just to let people know what's going on:

[Valera, Jenne]

Valera noticed that lots of things in and around the PSL table are drifting with temperature.  This is why he and Steve installed a temp sensor on the table earlier today.

PSL_Temp_drift_5May2011.png

Since the alignment into the PMC, and also the alignment downstream of the PMC have been drifting in angle, we supposed that it might be the PMC itself which is changing somehow with temperature.  We don't have a good idea of how exactly it is sensitive to temperature, but we're working on figuring it out.

Round 1 of testing:  We put a foil hat over the PMC to shield it from the HEPA air blowing directly down on top of it.  I made sure that the foil is also covering the PZT and the metal ring at the end of the PMC, because this could potentially be the problem (metal is usually more temperature sensitive than glass, or the PZT itself could be changing, either of which could make the end mirror twist, and change the alignment of the PMC).  We'll see later if this did anything useful or not. 

I have photos of the aluminum foil setup, which I will post later when I get back to the lab after teaching. 

P5050092small.jpg

  4260   Tue Feb 8 13:26:11 2011 AidanSummaryGreen LockingTemperature dependence of phase change of green on reflection

 I did a quick back of the envelope calculation of the expected green phase change on reflection from the aLIGO ITM.

The phase change per nm, K1 = delta phi/delta Lambda, around 532nm is ~1.5 degrees/nm (from the LMA data) [this number is approximately 100x smaller at 1064nm]

I assumed that very small changes in the thickness of the coating appear equivalent to shifting the spectra for reflection/transmission/phase-change-on-reflection up or down by delta lambda, where

delta Lambda/Lambda = delta h/h

where h is the total thickness of the coating and delta h is the change in the thickness of the coating.

Assume that delta h/h = alpha deltaT, where alpha is the coefficient of thermal expansion and delta T is the change in temperature. (approximately 1K)

Then delta phi = K1* Lambda * alpha * delta T = 1.5 degrees/nm * 532nm * 10^-5 K^-1 * 1.0 K =  8 * 10^-3 degrees.

Assume that 360 degree phase change corresponds to one FSR.

Therefore, the frequency shift due to temperature change in the coating = 8*10^-3/360 * FSR = 2.2 *10^-5 * FSR.

Therefore, the expected frequency shift per degree temperature change = 2.2*10^-5 * FSR [Hz/K]

  3071   Sat Jun 12 18:03:00 2010 sharmilaUpdateelogTemperature Controller

Kiwamu and I setup a serial port terminal for receiving data from TC200 via a RS-232 USB interface. It was done using a Python code. Some command definitions need to be done to get the output from TC-200.

  1942   Tue Aug 25 11:02:39 2009 ranaSummaryPSLTemperature Box

The PSL Temperature Box (D980400-B-C, what kind of numbering scheme is that?) modified at LHO/LLO ~8 years ago to have better resolution on the in-loop temperature sensors.

I haven't been able to find a DCN / ECN on this, but there's an elog entry from Hugh Radkins here.  I'm also attaching the PDF of the latest drawing (circa 2000) from the DCC.

The schematic doesn't show it, but I am guessing that the T_SENSE inputs are connected to the AD590 chips, and that 4 of these are attached somehow to the RefCav can. IF this is true, I don't understand why there are input resistors on the LT1125 of U1; the AD590 is supposed to be a current source ?

Peter King is supposed to be coming over to work on this today so whoever spots him should force/cajole/entice him to elog what he's done. Film him if necessary.

 

I also think R1-8 should be swapped into metal film resistors for stability. The datasheet says that it puts out 1 uA/K, so the opamps put out 10 mV/K.

J8 and JP1 should be shorted to disable both the tidal and VME control input. Both are unused and a potential source of drift.

Attachment 1: D980400-B.pdf
D980400-B.pdf
  1599   Mon May 18 10:06:56 2009 carynUpdatePEMTemp sensor

Quote:
To see if Caryn's data dropouts were happening, I looked at a trend of all of our temperature channels. Looks OK now.

Although you can't see it because I zoomed in, there's a ~24 hour relaxation happening before Caryn's sensors equilibrate.
I guess that's the insulating action of the cooler? We need a picture of the cooler in the elog for posterity.[/quote


Dropouts can't been seen with a minute trend, only a second trend. No big deal, but they are still occurring. See plot below.

The 24hr relaxation period is due to the cooler and some metal blocks that were cooled in the freezer and then put in the cooler to see if the relationship between the temp sensors changed with temperature. The relationship is not linear, which probably means there is some non-linearity in each temperature sensor's relationship to temperature. So, when calibrating them with Bob's temp sensor, more than 2 data points need to be collected.

Picture of cooler for posterity is attached
Attachment 1: datadropout.png
datadropout.png
Attachment 2: coolerpic1.jpg
coolerpic1.jpg
Attachment 3: coolerpic2.jpg
coolerpic2.jpg
  1600   Mon May 18 15:31:11 2009 ranaUpdatePEMTemp sensor

Quote:
Picture of cooler for posterity is attached


I'm puzzled as to why the minute trend doesn't pick this up; its clearly there in the full data.

Looks like its several samples too. Can someone please reboot this DCU and see if the problem goes away?
Attachment 1: Untitled.png
Untitled.png
  8058   Mon Feb 11 16:29:33 2013 JenneUpdateLockingTemp oplev for PR2; ITMX temporarily has no oplev

[Yuta, Jenne]

In an effort to see what is going on with the beam spot motion, and to investigate whether or not it might be caused by passive TT motion, Yuta and I installed some oplev mirrors in-vac, to make a PR2 oplev.

Yuta did not move either of the in-vac oplev mirrors that are for ITMX.  Instead, he took the incident red beam as it was, and put a spare in-vac oplev mirror there.  Then he used another spare oplev mirror to get the beam out, and on to the one out-of-vac steering mirror before the QPD.  I then steered the out of vac mirror to center the beam on the QPD.

This means (1) that ITMX cannot have an oplev right now, although the HeNe was off anyway, and (2) that as soon as we take these spare oplev mirrors out, we should immediately have ITMX oplev back (may need to steer out of vac mirror to get beam onto QPD).

Yuta is currently taking measurements to see if PR2 motion has high coherence with the intracavity motion.

  13868   Fri May 18 20:03:14 2018 PoojaUpdateCamerasTelescopic lens solution for GigE

Aim: To find telescopic lens solution to image test mass onto the sensor of GigE camera.

I wrote a python code to find an appropriate combination of lenses to focus the optic onto the camera keeping in mind practical constraints like distance of GigE camera from the optic ~ 1m and distance between the lenses need to be in accordance with the Thorlab lens tubes available. We have to image both the enire optic of size 3" and beam spot of 1" using this combination of lens. The image size that efficiently utilizes the entire sensor array is 1/4". Therefore the magnification required for imaging the entire optic is 1/12 and that for the beam spot is 1/4.

I checked the website of Thorlabs to get the available focal lengths of 2" lenses (instead of 1" lenses to collect sufficient power). I have tried several combination of lenses and the ones I found close enough to what is required have been listed below along with thier colorbar plots.

a) 150mm-150mm (Attachment 2 & 3)

With this combination, object distance varies like 50cm for 1" beam spot to 105cm for 3" spot. Therefore, it posses a difficulty that there is a difference of ~48cm in the distances between the optic and camera in the two cases: imaging the entire optic and the beam spot.

b) 125mm-150mm (Attachment 4 & 5)

With this combination, object distance varies like 45cm for 1" beam spot to 95cm for 3" spot. There is a difference of ~43cm in the distances between the optic and camera in the two cases: imaging the entire optic and the beam spot.

c) 125mm-125mm (Attachment 6 & 7)

The object distance varies like 45cm for 1" beam spot to 90cm for 3" spot. There is a difference of ~39cm in the distances between the optic and camera in the two cases: imaging the entire optic and the beam spot.

Sensitivity check was also done for these combination of lenses. An error of 1cm in object distance and 5mm in the distance between the lenses gives an error in magnification <2%.

The schematic of the telescopic lens system has been given in Attachment 8.

 

Attachment 1: Untitled.png
Attachment 2: plot_2018-05-18_tel-lens_150_150_1.pdf
plot_2018-05-18_tel-lens_150_150_1.pdf
Attachment 3: plot_2018-05-18_tel-lens_150_150_3.pdf
plot_2018-05-18_tel-lens_150_150_3.pdf
Attachment 4: plot_2018-05-18_tel-lens_125_150_1.pdf
plot_2018-05-18_tel-lens_125_150_1.pdf
Attachment 5: plot_2018-05-18_tel-lens_125_150_3.pdf
plot_2018-05-18_tel-lens_125_150_3.pdf
Attachment 6: plot_2018-05-18_tel-lens_125_125_1.pdf
plot_2018-05-18_tel-lens_125_125_1.pdf
Attachment 7: plot_2018-05-18_tel-lens_125_125_3.pdf
plot_2018-05-18_tel-lens_125_125_3.pdf
Attachment 8: tel_design.pdf
tel_design.pdf
  10185   Fri Jul 11 15:29:26 2014 HarryUpdateGeneralTelescope With Collimator

 I used a la mode to make a design for the coupling telescope with a 3.3um target waist, that included the collimator in the overall design. The plot is below, and code is attached.

The components are as follows:

 label         z (m)     type    parameters         

   -----         -----     ----    ----------         

    lens1         0.7681    lens    focalLength: 0.5000

    lens2         0.8588    lens    focalLength: 0.0350

    collimator    0.8832    lens    focalLength: 0.0020

 

The z coordinates are as measured from the beam waist of the NPRO (the figure on the far left  of the plot).

Moving forward, this setup will be used to couple the NPRO (more specifically, the AUX lasers) light into the SM 980 fibers, as well as to help characterize the fibers themselves.

Ultimately, this will be a key component in the Frequency Offset Locking project that Akhil and I are working on, as it will transport the AUX light to the PSL, where the two beams will be beaten with each other to generate the input signal to the PID control loop, which will actuate the temperature servos of the AUX lasers.

Attachment 1: telescope_2.zip
Attachment 2: telescopeWCollimator.png
telescopeWCollimator.png
  12998   Thu May 18 15:20:29 2017 jigyasaSummarytelescope designTelescope Design for the Gig-E cameras

With the objective of designing a telescope system for the Gig-E, a system of two lenses is implemented. A rough schematic of the telescope system is attached. Variables in the system include the focal lengths of the two spherical lenses(f1, f2), distance between the lenses(t), distance between the test mass and the lens combination(u), distance between the other lens and the sensor(v). Also the size of the object to be desired ranges from 3’’ which is the size of the test mass to 1’’ which is approximately focusing on the beam spot implying that the required magnification ranges from 0.06089 to 0.1826 (since the sensor image circle size if ¼”)
The lenses are selected to be 2” in diameter so as to ensure sufficient collected power.

Going through the focal lengths available, namely 50, 100, 150, 200, 250 mm, and noting that the object distance would be within the ranges of 1500 to 2500 mm, plots of various accessible u and v for different values of t were obtained. This optimization was done to ensure the proper selection of the lenses. Additionally, a sensitivity analysis was performed and plots depicting the dependence of magnification on the precision limiting measurements of u (1 mm) and t (5 mm) were obtained. (These were scatter plots quantifying the deviation from the desired magnification ranges). The plots depict the error term induced on the magnification if there was an error in measuring the distance between the lenses as 5mm and if the precision in measuring the object to lens distance by 1mm.

The telescope design might be limited by spherical aberrations and coma, which might be resolved by either using aspherical lenses or by increasing the f-number (typically with an f number around 5 or 6). The use of aspherical lenses particularly parabolic lenses was considered, however this was found to be quite an expensive route. 

Analyzing the plots and taking into consideration the restrictions of the slotted lens tubes, the precision in measurement of the distances, a 150 mm- 250mm focal length solution is proposed. With a diameter of 2”, the f number is computed to be 2.95 and 4.92. With this combination and the object distances lying between 1500 to 2500 mm, the image distance to the sensor varies between 51 to 100mm. So a slotted lens tube controlling the distance between the lenses would be required.

I also considered a combination of focal lengths 250mm and 250mm, as then both of the lenses would at least have an f number of 4.92. The results for this combination are also attached. The image distance from the lens combination is about a 100 to a 140 mm. However, this would require much longer slotted length tubes thereby adding to the cost of the system. The number of accessible u-v points is the same as that for the 150-250 combination. 

I am still trying to search for a much more concrete way of quantifying aberrations.

Attachment 1: ray.png
ray.png
Attachment 2: Schematic.png
Schematic.png
Attachment 3: 150-250uv.png
150-250uv.png
Attachment 4: 150-250error.png
150-250error.png
Attachment 5: 250-250.png
250-250.png
Attachment 6: 250-250error.png
250-250error.png
  14644   Fri May 31 01:38:21 2019 KruthiUpdateCamerasTelescope

[Kruthi, Milind]

Yesterday, we were able to capture some images of objects at a distane of approx 60cm (see the attachment), with the GigE mounted onto the telescope. I think, Johannes had used it earlier to image the ETMX (https://nodus.ligo.caltech.edu:8081/40m/13375). His elog entry doesn't say anything about the focal length of the lenses that he had used. The link to the python code he had used to calculate the lens solution wasn't working. After Gautam fixed it, I took a look at it. He has used 150mm (front lens) and 250mm (back lens) as the focal length of lenses for the calculation. Using the lens formula and an image of a nearby light source, with a very rough measurement, I found the focal lengths to be around 14 cm and 23 cm. So, I'm assuming that the lenses in the telescope are of same focal lengths as in his code, i.e 150mm and 250mm.

Attachment 1: telescope_mug_image.pdf
telescope_mug_image.pdf
  14646   Mon Jun 3 16:40:48 2019 ranaUpdateCamerasTelescope

no BMP files crying

  6081   Wed Dec 7 09:56:14 2011 rana imitation of steveOmnistructureEnvironmentTelephone Map

 This is the fone storree 

we should turn off 3977,3979 and 2351 has no function

 

Edit, JD:  x8925 is at the Visitor desk, and isn't on the map.

  15551   Tue Sep 1 01:49:49 2020 KojiUpdateElectronicsTeledyne AP1053 etc were transported

Teledyne AP1053 etc were transported from Rich's office to the 40m. The box is placed on the shelf at the entrance.

My record tells that there are 7 AP1053 in the box. I did not check the number this time.

Attachment 1: 20200831203756_IMG_9931.jpg
20200831203756_IMG_9931.jpg
Attachment 2: 20200831203826_IMG_9932.jpg
20200831203826_IMG_9932.jpg
Attachment 3: 20200831205126_IMG_9934.jpg
20200831205126_IMG_9934.jpg
  13569   Tue Jan 23 01:56:18 2018 gautamUpdateElectronicsTeledyne AP1053

I have acquired 5 pieces of the Teledyne AP1053 from Koji - these are now at the 40m. I will determine an appropriate location for storage of these and update. We are also looking to acquire 5 more of these. The combination of high power output (26dBm), low gain (10dB), and low noise figure (1.5dB) are quite uncommon in an amplifier and so these should be used only when such properties are required simultaneously.

*Steve informs me that these amps have been stored in the RF cabinet E6 along the east arm.

Steve's note: Teledyne rf amp product selection guide

                   Teledyne rf low noise amp guide

 

Attachment 1: DSC00022.JPG
DSC00022.JPG
  14485   Mon Mar 18 18:10:14 2019 KojiSummaryGeneralTask items and priority

[Gautam/Chub/Koji] ~ Mini discussion

Maintenance / Upgrade Items

(Priority high to low)

  • TT/IO suspension upgrade (solidworks work) -> order components -> TT characterization
  • Acromag upgrade c1susaux
    • Produce spread sheetfor DB files. Learn new format of the DB file with Acromag. Develop a python code for the DB file generation (Jon->Koji)
  • Satellite Box upgrade
    • Rack mount? Front panel DB connectors. New circuits (PD-LED)
       
  • Acromag iscaux1/2 & isc whitening upgrade
     
  • new RC mirror characterization -> installation
  2639   Thu Feb 25 11:21:06 2010 KojiUpdateGeneralTanks opened

[Steve, Bob, Joe, Zach, Alberto, Kiwamu, Koji]

We opened the OMC-IMC access connector, ITMX North door, and ITMY West door.
We worked from 9:30-11:00.
The work was quite smooth thanks to the nice preparation of Steve as usual.

Thank the team for the great work!

 

  4088   Wed Dec 22 15:47:22 2010 KojiUpdateVACTank closing procedure

[Jenne Kiwamu Joe Osamu Steve Koji]

Yesterday (21st), we closed the BSC and the four testmass chambers.

We splitted the team into three.

- Wiping team (Jenne/Kiwamu)
- Suspension team (Osamu/Koji)
- Door closing team (Joe/Steve)

While the wiping team was working, the suspension team prepared the next suspension.
Once the mirror was wiped, the suspension team restored that suspension at the position of the markings on the table.

After the wipe of the first mirror, the wiping team got experienced and they were the fastest among the teams.
So the wiping team worked as the second suspension team when necessary.

All of us became the closing team after the last suspension has been restored.

We checked that we still have the Michelson fringes and the oplev pointings.

In total, the work was very efficient such that we only took four hours for the entire process.

We left the suspension marking on the optical tables because they are quite useful.

  5274   Sat Aug 20 23:01:39 2011 JennyUpdatePSLTaking temperature step-response data: successes and tribulations

After finishing my last elog entry, I monitored the digital loop's error signal (the control signal for the fast loop) and the output to the laser heater remotely, (from West Bridge), using dataviewer. The ref cav surrounding can temperature was set to 36 degrees C.

With the loop closed and a gain of 0.008, after seeing the output voltage to the laser heater (TMP_OUTPUT) remain fairly constant and the error signal (TMP_INMON) stay close to zero for ~3 hours, I tried to step the temperature. (This was at 2am last night). I was working remotely from West Bridge. To step the temperature I used the following command:

ezcawrite C1:PSL-FSS_RCPID_SETPOINT 35.5

 

Rather than change the can temperature to 35.5 C, it outputted:

C1:PSL-FSS_RCPID_SETPOINT=0.

 

It had set the setpoint to 0 degrees C, which was essentially turning the heater off. I tried resetting it back to 36 and had no luck. I tried changing the syntax slightly.: ezcawrite C1:PSL-FSS_RCPID_SETPOINT=36 and ezcawrite C1:PSL-FSS_RCPID_SETPOINT (36). No success.

I ran over to the 40m and changed the temperature back to 36 manually. The in-loop temp sensor had decreased to 31.5 degrees C before I was able to step the setpoint back up. The system seems to have recovered from this large impulse though, and the laser has remained locked.

5hourwbigimpulse.jpg

 5hourwbigimpulse2.jpg

(5 hours of minute-trend data)

From left to right: 

Top: Out-of-loop can temp sensor; Voltage sent to heat can

Middle: signal sent to heat the laser (TMP_OUTPUT); room temp

Bottom: Error signal for slow loop (sampled control signal from fast loop); In-loop can temp sensor

 

At 9:30 this morning (7 and a half hours after accidentally setting the setpoint to zero), I came in to the 40m. TMP_OUTPUT was still decreasing but was slowing somewhat, so I decided to step the can temperature up half a decree to 36.5 C.

TMP_OUTPUT responded to the step, but it is also oscillating slowly with room-temperature changes, and these oscillations are on the same order as the step response. The oscillations look like the room-temp oscilations, but inverted. (TMP_OUTPUT reaches maxima when RMTEMP reaches minima). Oddly, there does not appear to be much of a time delay between the room temperature and TMP_OUTPUT signals. I would expect a time delay since there's a time constant for a room-temperature change to propagate into the cavity. Perhaps the laser itself is susceptible to room-temperature changes and those propagate into the laser cavity on a much faster time scale. I don't know the thermal coupling of ambient temperature changes into the laser.

23hoursbefore920pm.jpg

23hoursbefore920pm2.jpg

(24-hours of second-trend data)

 

Options are:

--If the system can handle it, do a larger temperature step (3 degrees, say), so that I can more clearly distinguish the oscillations with room temp from the step response.

--Insulate the cavity with foam (will in principle make the temperature over the can surrounding the ref cav more uniform and less affected by room temperature changes).

--Insulate the laser? Is this possible?

--Leave the system as is and, as a first approximation, fit the room-temp data to a sine wave and subtract it off somehow from my data to just see the step response.

--Don't bother with steps and just try to get the transfer function from out-of-loop temperature (RCTEMP, which is affected by temperature noise from the room) to TMP_OUTPUT via taking the Fourier transforms of both signals.

 

I'm flying out tomorrow morning, so I'll either need to figure out how to step the temperature set point of the can remotely, successfully, or I'll need someone to manually enter in the temperature steps for me in the control room.

  17112   Mon Aug 29 18:25:12 2022 CiciUpdateGeneralTaking finer measurements of the actuator transfer function

Took finer measurements of the x-arm aux laser actuator tranfer function (10 kHz - 1 MHz, 1024 pts/decade) using the Moku.

--------------------------------------

I took finer measurements using the moku by splitting the measurement into 4 sections (10 - 32 (~10^4.5) kHz, 32 - 100 kHz, 100 - 320 kHz, 320 - 1000 kHz) and then grouping them together. I took 25 measurements of each ( + a bonus in case my counting was off), plotted them in the attached notebook, and calculated/plotted the standard deviation of the magnitude (normalized for DC offset). Could not upload to the ELOG as .pdf, but the pdf's are in the .zip file.

--------------------------------------

Next steps are to do the same stdev calculation for phase, which shouldn't take long, and to use the vectfit of this better data to create a PZT inversion filter.

Attachment 1: PZT_TF_fine.png
PZT_TF_fine.png
Attachment 2: PZT_TF_fine_mag_stdev.png
PZT_TF_fine_mag_stdev.png
Attachment 3: ATF_fine.zip
  660   Fri Jul 11 20:16:01 2008 EricDAQCamerasTaking data from the GC 750 Camera
Mafalda has been set up with a background process to constantly take data from the GC 750 camera (at the end of the x-arm) for the weekend. This camera will otherwise be inoperable until then.

In the small chance that this slows either Mafalda or the network to a crawl, the process to kill should have PID 26265.
  3007   Fri May 28 11:35:33 2010 josephbUpdateCDSTaking a step backwards to get stuff running

I've modified the lsc.mdl and lsp.mdl files back to an older configuration, where we do not use an IO processor.  This seems to let things work for the time being on megatron while I try to figure out what the is wrong with the "correct" setup which includes the IO processor.

Basically I removed the adcSlave = 1 line in the cdsParameters block.

I've attached a screen shot of the desktop showing one filter bank in the LSP model passing its output correctly to a filter block in the LSC.  I also put in a quick test filter (an integrator) and you can see it got to 80 before I turned off the offset.

So far this is only running on megatron, not the new machine in the new Y end.

The models being use for this are located in /cvs/cds/caltech/cds/advLigoRTS/src/epics/simLink

Attachment 1: working_lsc_lsp.png
working_lsc_lsp.png
  14049   Tue Jul 10 16:59:12 2018 Izabella PastranaHowToComputer Scripts / ProgramsTaking Remote TF Measurements with the Agilent 4395A

I copied the netgpibdata folder onto rossa (under the directory ~/Agilent/), which contains all the necessary scripts and templates you'll need to remotely set up, run, and download the results of measurements taken on the AG4395A network analyzer. The computer will communicate with the network analyzer through the GPIB device (plugged into the back of the Agilent, and whose communication protocol is found in the AG4395A.py file in the directory ~/Agilent/netgpibdata/).

The parameter template file you'll be concerned with is TFAG4395Atemplate.yml (again, under ~/Agilent/netgpibdata/), which you can edit to fit your measurement needs. (The parameters you can change are all helpfully commented, so it's pretty straightforward to use! Note: this template file should remain in the same directory as AGmeasure, which is the executable python script you'll be using). Then, to actually set up, run, and download your measurement, you'll want to navigate to the ~/Agilent/netgpibdata/ directory, where you can run on the command line the following: python AGmeasure TFAG4395Atemplate.yml

The above command will run the measurement defined in your template file and then save a .txt file of your measured data points to the directory specified in your parameters. If you set up the template file such that the data is also plotted and saved after the measurement, a .pdf of the plot will be saved along with your .txt file.

Now if you want to just download the data currently on the instrument display, you can run: python AGmeasure -i 192.168.113.105 -a 10 --getdata

Those are the big points, but you can also run python AGmeasure --help to learn about all the other functions of AGmeasure (alternatively, you can read through the actual python script).

Happy remote measuring! :)

 

 

 

 

  13077   Fri Jun 23 02:43:43 2017 KaustubhHowToComputer Scripts / ProgramsTaking Measurements From AG4395A

Summary:

I have written a code(a basic one which needs a lot of improvements, but still does the job) for taking multiple measurements from the AG4395A. I have also written a separate code for plotting the data taken from the previoius code along with the error bars upto 1 standard deviation.

 

Details on How To Operate AG4395A:

  1. Under 'Measurement' tab, press the 'Meas' button and select the Analyzer Type (Network Analyzer or Spectrum Analyzer).
  2. Then under the same options select which 'ratio' needs to be measured (A/R, B/R or A/B).
  3. Then press the 'Format' button to select what needs to be measured (Eg - Log|Mag|, Phase, etc.).
  4. In order to measure and see two channels at the same time (Eg - Log|Mag| and Phase), press the 'Display' button and select 'Dual Channel'.
  5. Using the 'Scale' button we can set the scale/div or use autoscale and also set the attenuator values of the different channels.
  6. The 'Bw/Avg' option gives us an averaging option which averages few sets of data to produce the result. In doing this we lose quiet a lot of data and the resulting plot isn't able to give us the information on the statistical errors.
  7. This option also allows us to set the 'Intermediate Frequency' Bandwidth. This basically dictates the sampling rate of the Analyzer. The lower the IF bw, the higher is lesser is the noise (due to less uncertainty in Frequency).
  8. The 'Cal' button helps us calibrate the Analyzer to the current connections and signals. This is done because there is usually a difference in the 'cable lengths' for the two channels which introduces an extra phase term depnding upon the rf frequency. The calibration can be simply done by removing the Device Under Test (DUT) and diectly connecting the coaxial cables to the channels. After this the 'Calibrate Menu' allows us to calibrate the response using the short, open and thru methods.
  9. Now, under the 'Sweep' tab, the 'Sweep' button allows us to select various sweep options such as 'Sweep Time' (Auto, or set a time), 'Number of Points' (b/w 201-801) and 'Sweep Type' (Linear, Log, List Freq. etc.).
  10. Using the 'Source' button we can set the source power in dBm units (Usually kept as -20 to -10 dBm).
  11. The Scan Range can be set in a few ways such as using the start and end points or using the center and span range/width.
  12. After setting up all of the above, we can take the measurement either from the analyzer itself or using one of the control PCs. The command to download the data from AG4395A is netgpibdata -i 192.168.113.105 -d AG4395A -a 10 -f [filename].

 

Brief Details on How the 'AGmeasure' command works:

AGmeasure is a python script developed by some of the people who work at 40m. It is set as a global command and can be used from within any directory. The source code is in the scripts folder on the network, or else it can also be found in Eric Quintero's git repository. This command accepts at the very least a parameter file. This is supposed to be a .yml file. A template (TFAG4395Atemplate.yml) can be found in the scripts folder or in Eric's repo. There are some other options that can be passed to this command, see the help for more details.

 

The Multi_Measurement Script:

This script calls the 'AGmeasure' command repetitively and keeps storing the data files in a folder. Right now, the script needs to be fed in th template file manually at prompt.

 

The Test_Plotting Script:

This script plots the a set of data files obtained from the above mentioned script and produces a plot along with the errors bands upto 1 standard deviation of the data. The format (names) and total number of text files need to be explicitly known, for now at least.

 

Attachments:

  1. The output test files and the two scripts.
  2. This is the 'Bode Plot' for a data set made using the above two scripts.

 

To Do:

  • Improve upon the two scripts to be as compatible as the AGmeasure function itself.
  • Try and incorporate the whole script into AGmeasure itself along with improving upon the templates.
  • The above details, with some edits perhaps, can go into the 40m wiki too(?).

 

Update: Increased the font size in the plot. Added a few comments to the two scripts

To Do: Need to consider the transfer function as a single physical quantity (both the magnitude and phase) and then take the averages and calculate the standard deviation and then plot these results. 

 

EDIT:

The attachment with the test files and the code now also contains a pdf with all the relations/equations I have used to calculate the averages and errors.

Attachment 1: Test_Files_and_Code.zip
Attachment 2: Bode_Plot_with_Error_Bands.pdf
Bode_Plot_with_Error_Bands.pdf
  869   Fri Aug 22 10:39:41 2008 JenneUpdateSUSTaking Free Swinging spectra of PRM, SRM, ITMX, BS
I'm taking free swinging spectra of PRM, SRM, ITMX and BS, so I've turned off their watchdogs for now. I should be done around 11:15am, so I'll turn them back on then.
  13926   Thu Jun 7 14:35:26 2018 keerthanaUpdateelogTable- useful for doing the scanning.

I think this table will help us to fix the scanning range of the Marconi frequency. This will also help in predicting the position of the resonance peak corresponding to the injected frequency.

fdiff = fm ±80 MHz ;                     fdiff = N*FSRy ;              FSRy = 3.893 MHz.

N = Integer number fdiff =injected fm = Marconi frequency
1 3.893 76.107
2 7.786 72.214
3 11.679 68.321
4 15.572 64.428
5 19.465 60.535
6 23.34 56.66
7 27.251 52.749
8 31.144 48.856
9 35.037 44.963
10 38.93 41.07
11 42.79 37.21
12 46.716 33.284
13 50.609 29.391
  2419   Tue Dec 15 17:16:22 2009 KojiUpdateGeneralTable distance measurements

During the vent we have tried to measure the distances of the optical tables for BS-ITMX and BS-ITMY.
We need to take into account the difference between the AutoCAD drawing and the reality.

X direction distance of the table center for BS and ITMX:
84.086" (= 2135.8mm)
(This is 84.0000" in AutoCAD drawing)

Y direction distance of the table center for BS and ITMX:
83.9685" (= 2132.8mm)
(This is 83.5397" in AutoCAD drawing)

We used two scales attached each other in order to measure the distance of the certain holes on the tables.

We got more numbers that were estimated from several separated measurements.
I think they were not so accurate, but just as a record, I also put the figure as an attachment 2.

Attachment 1: Table_distance_by_metal_scale.pdf
Table_distance_by_metal_scale.pdf
Attachment 2: Table_distance_by_chambers.pdf
Table_distance_by_chambers.pdf
  8282   Wed Mar 13 03:12:47 2013 Manasa, JenneUpdateLockingTWO arms TWO colors

[Jenne, Manasa]

2 colors 2 arms realized!

1. Spot centering:

We spot centered the IR in both arms.
- Use TT1 and TT2 to center in Y arm (I visually center the spots on the ITM and ETM and then use TTs iteratively)
- Use BS-ETM to center in X arm

Spot positions after centering
               X arm            Y arm
         itmx    etmx        itmy    etmy
pitch    -0.86    0.37        1.51    0.05
yaw      0.01    -0.1        0.08    0.10


2. TT1 drifting in pitch (Bistable)
During the arm alignment routine for spot centering, we observed that TRY dropped (from TRY = 0.9 until the arm lost lock) every 40minutes or so. The arm was relocked by moving TT1 in pitch. The (locking - unlocking due to drift - relocking) cycle was monitored and we observed that it was bistable i.e. if TT1 was moved up in pitch (0.2 on the slider) to relock for the first time ; the next time it lost lock, TT1 had to be moved down by nearly the same distance to relock the arm.
Moving TT2 or the testmasses did not help with relocking the arms; so TT1 seems to be the one causing all th trouble atleast for today.

3. ALS - green alignment

We then moved on to Ygreen.  We used the out of vac steering mirrors to center the beam on the 2 irises that are in place on the table, which was a good starting place.  After doing that, and tweaking a small amount to overlap the incident and reflected beams on the green steering mirrors, we saw some mode lock.  We adjusted the end table steering mirrors until the Ygreen locked on TEM00.  We then followed Rana's suggestion of locking the IR to keep the cavity rigid while we optimized the green transmission.  Yuta, while adjusting ITMY and ETMY (rather than the out of vac mirrors) had been able to achieve a green transmission for the Yarm of ~2700 counts using the GTRX DC PD that's on the table. We were only able to get ~2200, with brief flashes up to 2500.

After that, we moved on to the X arm.  Since there are no irises on the table, we used the shutter as a reference, and the ETM optic itself.  Jenne looked through the viewport at the back of the ETM, while Manasa steered mirrors such that we were on the center of the ETM and the shutter.  After some tweaking, we saw some higher order modes lock.  We had a very hard time getting TEM00 to stay locked for more than ~1 second, even if the IR beam was locked.  It looks like we need to translate the beam up in pitch.  The leakage of the locked cavity mode is not overlapped with the incident beam or the promptly reflected beam.  This indicates that we're pretty far from optimally aligned.  Manasa was able to get up to ~2000 counts using the same GTRX PD though (with the Ygreen shutter closed, to avoid confusion).  Tomorrow we will get the Xarm resonating green in the 00 mode.

We need to do a little cleanup on the PSL green setup.  Yuta installed a shutter (I forget which unused one he took, but it was already connected to the computers.), so we can use it to block the PSL green beam.  The idea here is to use the 4th port of the combining beam splitters that are just before each beat PD, and place a PD and camera for each arm.  We already have 2 PDs on the table connected to channels, and one camera, so we're almost there. Jenne will work on this tommorrow during the day, so that we can try to get some beat signals and do some handoffs in the evening.

  8283   Wed Mar 13 08:34:33 2013 yutaUpdateLockingTWO arms TWO colors

- I took the shutter from AS table to use it for the PSL green. It was sitting near MC REFL path unused (elog #8259).

- If X green lock is not tight, maybe temporarily increasing loop gain helps. This can be done by increasing the amplitude of the frequency modulation or increasing green refl PD gain. Also, if X green beam spot is too wiggly compared with Y green, it is maybe because of air flow from the air conditioner (elog #6849). I temporarily turned it off when I did X green steering last summer.

- X green transmission on PSL table reached ~270 uW last summer (elog #6849, elog #6914). Y green transmission is now ~240 uW and ~2700 counts at maximum. So, X green transmission should reach ~3000 in counts.

- Did you have to re-align TRX path? We moved the harmonic separator on X end table horizontally to avoid IR TRX clipping before beam centering on X arm (elog #8162). I wonder what is the current situation after the beam centering.

  8289   Wed Mar 13 16:29:25 2013 ManasaUpdateLockingTWO arms TWO colors

Quote:

- If X green lock is not tight, maybe temporarily increasing loop gain helps. This can be done by increasing the amplitude of the frequency modulation or increasing green refl PD gain. Also, if X green beam spot is too wiggly compared with Y green, it is maybe because of air flow from the air conditioner (elog #6849). I temporarily turned it off when I did X green steering last summer.

- Did you have to re-align TRX path? We moved the harmonic separator on X end table horizontally to avoid IR TRX clipping before beam centering on X arm (elog #8162). I wonder what is the current situation after the beam centering.

 - We tried locking with the air conditioning switched off at the X-end

- TRX path is unaltered (IR still goes through the center of the harmonic separator.

ELOG V3.1.3-