PMC_cal (m/V) = (1064 nm)/2 / V_FSR

scp Particle.st username@lhocds.ligo-wa.caltech.edu:/cvs/cds/lho/target/t0sandbox0

ssh username@lhocds.ligo-wa.caltech.edu

ssh ops@control0

cd /cvs/cds/lho/target/t0sandbox0

setup epics

make Particle.o

scp Particle.o controls@nodus.ligo.caltech.edu:/cvs/cds/caltech/target/c1psl/

netgpibdata.py -i 131.215.113.106 -d AG4395A -a 10 -f spectrum01

elogkeywd keyword1 keyword2 keyword3

To use the Sensoray 2250 USB frame grabber:

Ensure you have the following packages installed: build-essential, libusb-dev

Download the Linux manual and linux SDK from the Sensoray website at:

http://www.sensoray.com/products/2250data.htm

Go to the Software and Manual tab near the bottom to find the links.  The software can also be found on the 40m computers at /cvs/cds/caltech/users/josephb/sensoray/

The files are Manual2250LinuxV120.pdf and s2250_v120.tar.gz

Run the following commands in the directory where you have the files.

tar -xvf s2250_v120.tar.gz

cd s2250_v120

make

cd ezloader

make

sudo make modules_install

cd ..

At this point plug in the 2250 frame grabber.

sudo modprobe s2250_ezloader

Now you can run the demo with

./sraydemo or ./sraydemo64

Options will show up on screen.  A simple set to start with is "encode 0", which sets the recording type, "recvid test.mpg", which starts the recording in file test.mpg, and "stop", which stops recording.  Note there is no on screen playback.  One needs an installed mpeg player to view the saved file, such as Totem (which can screen cap to .png format) or mplayer.

All these instructions are on the first few pages of the Manual2250LinuxV120 pdf.

I tested the cryopump interlock today. It is touchy. I do not have full confidence in it.

I'm proposing that VC1 gate valve should be kept closed while nobody is working in the 40m lab.

How to open gate valve:

1, confirm temp of 12K on the gauge at the  bottom of the cryopump

2, if medm screen cryo reads OFF( meaning warm) hit reset will result reading ON (meaning cold 12K )

3, open VC1 gate valve if P1 is not higher than 20 mTorr

VC1 was closed at 18:25,

IFO condition: not pumped,

expected leak plus  out gassing should be less than 5 mTorr/day

The RGA is in bg-mode, annuloses are closed off

To set the demod phase for RF CARM, sensed at REFL2 (REFL 166I), it suffices to set the demod phase for REFL2 to be the optimal phase for controlling SRCL in a no-arm state.

For POX33, the ideal phase for single arm locking does not yield a zero-offset CARM signal.  So the offset needs to be manipulated digitally. 

 The Cryo pump is running reliably since April 22 hence there is no need to close VC1 repeatedly.

The photo switch interlock was put back onto the H2 vapor pressure gauge and it is working.

The Elog started crashing last night. It turns out I was the culprit, and whenever I tried to upload a certain 500kb .png picture, it would die. It has happened both when choosing "upload" of a picture, and when choosing "submit" after successfully uploading a picture. Both culprits were ~500kb .png files.

Restarting the framebuilder didn't work, but the problem now appears to be fixed.

Upon reflection, we also decided to try killing all open DTT and Dataviewer windows.  This also involved liberal use of ps -ef to seek out and destroy all diag's, dc3's, framer4's, etc.

That may have worked, but it happened simultaneously to killing the tpman process on fb40m, so we can't be sure which is the actual solution.

To restart the testpoint manager:

what you type is in bold:

rosalba> ssh fb40m

fb40m~> pkill tpman

The tpman is actually immortal, like Voldemort or the Kurgan or the Cylons in the new BG.  Truly slaying it requires special magic, so the pkill tpman command has the effect of restarting it.

In the future, we should make it a matter of policy to close DTTs and Dataviewers when we're done using them, and killing any unattended ones that we encounter.

Q. When should we use plano-convex lenses, and when should we use bi-convex?

As I had the same question from Jenne and Dmass in a month,
I just like to introduce a good summary about it.
Lens selection guide (Newport)
http://www.newport.com/Lens-Selection-Guide/140908/1033/catalog.aspx

At a first order, they have the same function.
Abberation (= non-ideal behavior of the lens) is the matter.

There are two new Matlab files on the svn in /mDV/extra/C1. 'mycsd.m' is to calculate the cross-spectral density between two channels, 'csd_40T_40T_SS1.m' calls this function with the available seismic channels and derives a self-noise spectrum for the vertical axis using all three seismometers. The method requires that there are no correlations between two instruments only which is a bad idealization for certain frequencies if you have seismometers of totally different types.

'mycsd.m' uses the high-gain, low-resolution Nuttall window (built-in Matlab function 'nuttallwin.m'). High-gain windows are used for broad-band spectra like seismic spectra, but it should be exchanged by another window if you plan to look at small-bandwidth features like peaks.

Since the three-channel analysis does not require knowledge of response functions, it could be used to evaluate the performance of the adaptive filter. For example, if three channels responding to the same signal are available, then the ratio of any two csds corresponds to one of the relative transfer functions. You can then compare this function with the result produced by the adaptive filter.

 The control room desk tops heights on the east side were lowered by 127 mm

The new APC Smart -UPS 2200VA is now running at  the vacuum rack. There are 2 load monitoring leds on out of 5

Maglev, dry pumps and roughing pumps are not using UPS.

The switch over went smoothly with Yoichi's help.

First we closed all vacuum valves and stopped the two small turbos.

Than turned power off to instruments in the vac-rack and VME: c1vac1 & c1vac2

Maglev was left running.

Now we moved the AC plugs from the wall receptacles over to the back of the UPS and powered them up.

Varian turbos were restarted and vacuum valves were restored in order to reach  vacuum normal condition.

See 40m Vacuum System States and Sequences Manual of 10-24-2001

Linux 3 desk top computer is out of order at the pump spool. We should replace it.

The vacuum control screen can be pulled up on a lap top: /cvs/cds/caltech/medm/c0/ve/VacControl_BAK.adj

I've created a 40m Google account. Please post all the 40m related photos to this site. If you don't already have it, download Picasa to make this easier.

40m Installation Photos">

the password is in the usual password place.

I drove MC2 in POS and used the resulting response in MC_F to calibrate the IOO-MC_L channel.

Yoichi did an excellent job of calibrating MC_F last year. I have used his calibration of MC_F (220 Hz/count @ DC) to get the MC_L calibration at DC as well as at high frequencies. The hardware dewhitening was OFF for all these measurements.

Method

1. For the DC measurement I excited C1:SUS-MC2_MCL_EXC at 0.0731 Hz. At these frequencies, the MC_L path has much more gain than the MC_F path. So this excitation at the error point makes the length path to drive itself to cancel the digital excitation. Since the overall MC servo gain is huge, this causes the MC_F path to compensate the residual MC_L motion. One can simply take the ratio of MC_L/MC_F to get the calibration of MC_L in Hz.

2. For the AC measurement, I engaged FM9 of the MC2_MCL filter bank. This guy is an elliptic LP with a notch at 660.38 Hz. I then drove MC2_LSC at 660.38 Hz with a sine wave of 500 counts amplitude. The notch makes the gain of the MC_L feedback zero at that frequency. So MC_F has to do all the work. We can simply measure the ratio of MC2_LSC/MC_F to get the AC calibration of MC2_MCL_OUT (aka IOO-MC_L) and MC2_LSC_OUT (aka LSC-MC_L).

Results:

MCF/MCL @ 0.0731 Hz = 569.4. So the MC_L calibration at DC is 220 x 569.4 = 125 kHz/count or 6.02 nm/count.

From this we would expect the AC calibration to be (6 nm/count)*(660.38/f_pend)^2 = 13.0 x10^-15 m/count.

The AC measurement gave 1445 counts_peak** of MC_F for the 500 counts (peak) excitation in MC2_LSC. From Yoichi's entry we get that the high frequency calibration of MC_F should be 0.089 Hz/count. So the MC_L calibration at 660 Hz is 0.089*1445/500 = 0.25 Hz / count or 12.3 x 10^-15 m/count. So the AC/DC ratio is close to 1.

Splitting the difference, the new official MC_L calibration is 5.87 nm/counts @ DC with a complex pole pair at 0.972 Hz.

** note:  To convert from the peak height observed in DTT with a 50% Overlap Hanning window you must use the following intuitive formula:  counts_peak = (counts / rHz) * sqrt(2 * BW). In this case, BW is the number that DTT reports as BW on the screen, NOT the BW that you asked for on the measurement tab.

*** note: when measuring peak heights in a DTT FFT, make sure to unclick the box for 'Bin' under the config tab. Bin suppresses peaks in a plot with a lot of points and is ON by default.

**** note: I have updated the MCF reference in the Templates directory with the Yoichi calibration - spectrum attached. This is probably the most accurate MCF spectrum we have ever put in the elog in the history of the 40m. The implication is that the VCO phase noise is ~5 mHz/rHz. Not bad.

***** note: with the OAF off, I drove a 1.55 Hz sine wave into MC1 and measured the ratio of MC1_MCL_OUT/IOO-MC_L. This gives the DC calibration of MC1_MCL_OUT = 7.98 nm/count.

I have gotten the hang of the procedure for measuring phase noise on the AOMs. 

Koji suggested I right up a short guide (wiki page?) on how to do this. 

I will finish up here, then go measure the AOMs at the other lab (may have to be tomorrow, after laser safety), and then write up the instructions.

Kiwamu, Alex and Zach are practicing mandatory IR-safety scan at the 40m-PSL

40m specific safety indoctrination were completed.

 Koji did a nice job increasing light power with some joggling.

1/4" exposure, standard room lights                                                                              3" exposure, slowly moving LED bar light from ~60 cm distance

Note:
Because of the light behind, the focus was attracted by the far objects...
Evenso the magnet ball looks better in the right picture.

The technique is as follows:
Use longer exposure time, move the LED bar illumination through the area like painting the light everywhere.
It is supposed to provide a picture with more uniform light and the diminished shadow.

(KA)

Need to measure the length of the cable, but too lazy to use a measuring tape?

Then you too can become an expert cable length measurer by just using an RF signal generator and a scope:

1. Disconnect or short (not 50 Ohm term) the far side of the cable.
2. Put a T on the near side of the cable.
3. Drive the input of the T with your signal source.
4. Look at the output of the T with the scope while sweeping the signal source's frequency knob.

The T is kind of acting like a beamsplitter in an asymmetric length Michelson in this case. Just as we can use the RF phase shift between the arms to measure the Schnupp asymmetry, we can also use a T to measure the cable length. The speed of light in the cable is documented in the cable catalog, but in most cases its just 66% of the speed of light in the vacuum.

The elog has been quite slow for the last two days. The cause is nodus, that has been slowing down the access to it.

I looked at the list of the running processes on nodus by typing the command prstat, which is the equivalent for Solaris of the Linux "top". I didn't see any particular process that might be absorbing too many resources.

I remember Rana fixing the same problem in the past but couldn't find his elog entry about that. Maybe we should just restart nodus, unless someone has some other suggestion.

 Problem solved. Nodus and the elog are running fine. It's just that the elog takes some time to make a preview of complex pdf attachments, like those in Kiwamu's entry 2405.

In order to see the Contec DO-32L-PE Digital output PCIe card with the new controls, we had to add the CDO32 part to the CDS_PARTS.mdl file in control /cds/advLigo/src/epics/simLink/ directory on megatron, as well as create the actual model mdl file (based on cdsDio.mdl) in the control/cds/advLigo/src/epics/simLink/lib directory. 

The CDO32.pm file (in /home/controls/cds/advLigo/src/epics/util/lib) has existed for some time, it was just missing the associated pieces in simlink.  However, Alex also checked out a newer version Dio.pm in the process.  As we are not using this part at this time, it should be fine.

The code now compiles and sees the digital output card.

You need a special care on this block as it turned out that the code does not compiled if the "constant" block is connected to the input. You must use appropriate block such as bitwise operator, as shown below.

Joe let me use the resonant EOM for GigE phase camera for a while.
Then, I immediately started to open it :)

it uses the MiniCIrcuits T5-1T transformer and a TOKO RCL variable inductor.

The photos are on the Picasa 40m album.

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

Steve showed me how to send an international fax today:

1. Load paper.
2. Dial:   011 - (country code) - number
3. Press START (either the black or color option)
4. wait for the screaming fax noise
5. Done

I just put a script in the /cvs/cds/caltech/scripts/general/netgpibdata/ directory to control the network analyzer called AG4395A_Run.py .   A section has been added to the wiki with the other GPIB script sections (http://lhocds.ligo-wa.caltech.edu:8000/40m/netgpib_package#AG4395A_Run.py)

I'd like to try installing an updated multi-threaded ezca extension later this week, allowing for 64-bit builds of GDS ezca tools, provided by Keith Thorne.  The code can be found in the LDAS CVS under gds, as well as in CDS subversion repository, located at 

https://redoubt.ligo-wa.caltech.edu/websvn/

Its under gds/epics/ in that repository.  The directions are fairly simple:

1) to install ezca with mult-threading in an existing EPICS installation
-copy ezca_2010mt.tar.gz (EPICS_DIR)/extensions/src
-cd (EPICS_DIR)/extensions/src
-tar -C -xzf ezca_2010mt
-modify (EPICS_DIR)/extensions/Makefile to point 'ezca' at 'ezca_2010mt'
-cd ezca_2010mt
-set EPICS_HOST_ARCH appropriately
-make


I took data for the 2 NPRO PLL using the script I wrote for the AG4395, but it is very noisy above about 1 MHz.  I assume this is something to do with the script (since I am fairly confident we don't have 600 dB response in the PZT), so I will go in tomorrow to more carefully understand what is going on, I may need to include a bit more latency in the script to allow the NA to settle a bit more.  I am attaching the spectrum just to show the incredibly high noise level, 

In order to minimize the diffusion of more dust particles into the vented IFO vacuum envelope

BEFORE opening chamber:

-Have a  known plan,

-Heavy 1" thick door requires 3 persons- of  one experienced and one certified crane operator and steel tow safety shoes

-Block IFO beams, be ware of experimental set up of other hazards: 1064,  visible or new-special installation

- Look at the particle counter, do not open above 6,000 particles of 0.5 micron. Construction activities are winding down. See  plot of 35 days since we  vented.

-Have clean door stand for heavy door, covered with merostate at the right location and dry-clean screws for light covers,

-Prepare lint free wipers for o-rings,(no solvent on o-ring!) Kimwipes for outside of chamber and metal covers, methanol and powder free gloves

-Wipe with wet Kimwipe-tissue of methanol around the door, chamber of interest and o-ring cover ring

-Cut door covering merostate and tape it into position,..if in place...check  folded-merostate position, if dusty... replace it

-Is your cleanroom garment clean?.......if in doubt ....replace it

-Keep surrounding area free and clean

-Make sure that HEPAs are running: PSL-enclosure, two mobile units and south end flow banch

-Check the tools: are they really clean? wipe it with wet Kimwipe, do you see anything on the Kimwipe?

-You are responsible to close chamber ASAP with light door or doors as you finished for the day.

Merostate cover down is appropriate during daily brakes.

Frank noticed that this particular SR560 had an offset on the output which was unzeroable by the usual method of tuning the trim pot accessible through the front panel.

I tried to zero the offset using the trimpots inside, but it became clear that the offset was due to a damaged FET, so Steve ordered ~20 of the (now obsolete*) NPD5564.

I replaced this part and adjusted the offsets and balanced the CMRR of the differential inputs mostly according to the manual (p. 17). There are a few notes that should be added to the procedure:

1. It can sometimes be that the gain proscribed by the manual is too high and saturates the output for large offsets. If that's the case, simply lower the gain, trim the offset, then return the gain to the specified value and trim again.
2. The limit in trimming the offset is the stick slip resolution in the trim pot. This can potentially leave the whole preamp in an acoustically sensitive state. I tapped the pots with a screwdriver after tuning to make sure it was in more of a 'sticky' rather than 'slippy' region of the knob. A better design would allow for more filtering of the pot.
3. In the CMRR tuning procedure it says to 'null sine wave output' but it should really say 'null the sine wave component at the drive frequency'. The best CMRR tuning uses a 1 kHz drive and leaves a residual 2 kHz signal due to the distortion imbalance (of the FETs I think).
4. The CMRR tuning upsets the DC offset trim and vice versa. The best tuning is gotten by iterating slightly (go back and forth once or twice between the offset and CMRR tuning procedures).

It looks like its working fine now. Steve's ordering some IF3602 (low-noise, balanced FET pair from Interfet) to see if we can drop the SR560's input noise to the sub-nV level.

Noise measured with the input terminated with a BNC short (not 50 Ohms) G=100, DC coupled, low-noise mode:

 To try the 3-corner hat method on the Marconis, I started to set up the measurement into the DAQ system.

I have set the bottom 2 in the PSL rack to 11.1 MHz. I use a ZP-3MH level 13 mixer as the phase detector. The top one is the LO, it has an output of +13 dBm.

The bottom one is the test unit, it has an output of +6 dBm (should be close to the right level - the IP3 point is +9 dBm). The top one has external DC FM modulation enabled with a FM dev range of 10 Hz.

Mixer output goes through a 50 Ohm in-line termination and then a BLP-5 low pass filter (Steve, please order ~7 of the BLP-1.5 or BLP-1.9 low pass filter from Mini-Circuits) and then into

the DC coupled of a SR560. After some gain and filtering that feedback goes back to the FM input of the top-Marconi to close the PLL. I adjusted the gain to be as small as possible and still stay locked and not

saturate the ADC.

The input to the SR560 is Tee'd into another SR560 with AC coupled input, G = 1000, low-noise. Its output is going directly to the ADC channel - C1:IOO-MC_DRUM1.

I calibrated the channel by opening the loop and setting the AC coupled gain to 1. This lets the Marconis beat at several Hz. The peak-peak signal is equivalent to pi radians.

As usual, I was befuddled by the FM input. For some reason I always forget that since its a straight FM input, we don't need any filtering to get a plain 1/f loop. The attached plot shows how we get bad gain peaking if you forget this and use a 0.03 Hz pole in the SR560.

The grey trace is the ADC signal with everything hooked up, but the RF input set to zero (via setting Carrier = OFF in the bottom Marconi). It is the measurement noise.

The BLUE trace is very close to the true phase noise beat of the two Marconis with a calibration error of ~5%. I have not corrected for the loop gain: its right now around a 1 Hz UGF and 1/f. Next, I will measure the loop and compensate for it in the DTT calibration.

Then I'll measure the relative phase noise of 3 of the signal generators to get the individual noises.

Bottom line is that the sensitivity of this approach is good and we should do this rather that use spectrum analyzers since its easy to get very long averages and high res spectra. To get 5x better sensitivity, we can just use the Rai-FET box instead of a SR560 for the readout, but just have to contend with its batteries. Also should try using BALUNs on the RF and LO signals to get rid of the ground loops.

To check the UGF, I increased the gain of the PLL by 10 and looked at how much the error point got suppressed. The green trace apparently has a UGF of ~50 Hz and so the BLUE nominal one has ~5 Hz.

The second attachment shows the noise now corrected for the loop gain. IF the two signal generators are equally noisy, then you can divide the purple spectrum by sqrt(2) to get the noise of a single source.

The .xml file is saved as /users/rana/dtt/MarconiPhaseNoise_100504.xml