Telescope front lens to wall distance 25 cm, GigE camera lenght 6 cm and cat6 cable 2cm
Atm3, Existing short camera can has 16cm lenght to lexan guard on viewport. Available 2" od periscope tube lenght is 8cm. The one in use 16 cm long.
Note: we can fabricate a lite cover with tube that would accomodate longer telescope.
Can we calibrate the AR coated M5018-SW and compare it's performance agains the 2" periscope
Look at the Edmond Optics 3" od camera lens with AR
This lower priced 1" apeture Navitar lens can be an option too.
Atm1, Now I can see dust. This is much better. The focus is not right yet.
Atm2, Chamber viewport wiped and image refocused. Actually I was focusing on the dust.
I calculated a better lens solution for the ETMX side view with the simple python script that's attached. The camera is still not as close to the viewport as we would like, and now the front lens is almost all the up to the end of the tube. With a little more playing around there maybe a better way, especially if we expand the repertoire of focal lengths. Using Steve's wonderful camera fixture I put the beam spot in focus. I turned the camera sideways for better use of the field of view, and now the beam spot actually fills the center area of the beam, to the point where we probably don't want more magnification or else we start losing the tails of the Gaussian.
We'll take a serious of images tomorrow, and will have an estimate of the scatter loss by the end of tomorrow.
I worked on the daughter board a little more in the evening. I have somehow managed to make the dark noise ~25% worse [Attachment #1].
After making all these changes, I re-installed the card in the eurocrate and repeated the measurement. The Q channel noise was close to the expected value (~50nV/rtHz), but the I channel is twice as noisy. I will continue this investigation tomorrow.
I tried replacing the AD797s on the daughter board with OP27s, and saw no significant improvement in the electronics noise of the demod board. Note that according to LISO, in this configuration, the voltage noise of the Op27 is expected to dominate the total noise of the daughter board. Measurement condition was that the RFPD input was terminated, but the LO input was still being driven (SR785 input range is -50dBVpk for all traces, and the input ranging was set to "UpOnly"). Need to do a more systematic investigation to figure out where this excess noise is coming from. I will upload photos of the board later.
This supports the hypothesis that something is wonky on the daughter board, because the purple trace should only be the quad sum of the orange and green traces. I will pull it out and have a look.
these are not the SR785 settings that you're looking for
Gautam and Steve,
All 3 show the same noise level ~80 nV / rt Hz at 1 kHz as shown. Batteries ordered to be replaced in the top 2
We'll do more measurement to see how can we get to 4 nV / rt Hz specification level.
To get low noise measurements on the SR785, you have to have the input range set to -50 dB, not +20 dB. Its not within the powers of commercial electronics ADCs to give you a 10 nV noise floor with +10 V input signals. The SR560 has an input referred noise of 5 nV/rHz, so the output noise should be 5e-9 x 500 = 2.5 uV/rHz. Your picture shows it giving 1 uV RMS, so you also need to use the PSD units.
I keep adding traces to this plot, here is the most complete one I have now. Looks like the input noise to the D040179 (measured at "Q out" SMA jack of D990511 with RFPD input terminated) is ~10nV/rtHz. This supports the hypothesis that something is wonky on the daughter board, because the purple trace should only be the quad sum of the orange and green traces. I will pull it out and have a look.
Some other follow-ups on the questions raised at the meeting:
I measured the output voltage noise of the Q output of the AS55 Demod Board with the PSL shutter closed, using the SR785 (see Attachment #1). The measured noise is consistent with the expected number of ~120nV/rtHz around 100Hz. I had measured the gain of this board from RFPD input to Q output to be ~5.1: so if the PD dark noise is 16nV/rtHz, this would be amplified to ~80nV/rtHz. Still a discrepancy of ~50%. I didn't measure the noise with the PD input terminated. Added the noise of the demod board output with the RFPD input terminated. The level of ~100nV/rtHz seems consistent with the actual PD dark noise being ~80nV/rtHz, as their quadrature sum is around 130nV/rtHz. Need to dig up the schematics for the demod board + daughter board, and check against LISO, to see if this is consistent with what is expected.
Also - I think I was using the wrong value of the DC power on the AS55 photodiode for shot noise calculations - 13mW was for REFL55, not AS55. I did a crude measurement of the power by sticking the Ophir power meter (filter removed) in front of the AS55 PD with the Michelson flashing around, and noticed the maximum value registered was ~1.2mW. So in the DRMI lock, there would be ~2.4mW, which is 10x lower than the value I was assuming. I've made the correction in the NB code, for the next time the plot is generated. A more rigorous measurement would involve sticking the Ophir in front of the AS110 PD during a DRMI lock. The light from the AS port is split by a 50-50 BS to the AS55 and AS110 PDs (so measuring at AS110 is a reasonable proxy for power at AS55), and the AS110 signals are not used for triggering in the DRMI lock, so this is feasible.
how about calibrate the DC channels so that you can just get the acutal power levels from the trend data?
My last characterization of the AS55 PD was on Feb 2013. ELOG 8100
There I said the dark noise at the PD output was 16nV/rtHz. I don't have the measurement of the Voltage noise at the output of the demod board.
Note that the PD can only be limited by shot noise when the DC current is larger then 4mA.
I spent this weekend doing a more careful investigation of the DRMI noise. I think I have some new information/insights. Attachment #1 is the noise budget (png attached because pdf takes forever to upload, probably some ImageMagick problem. The last attachment is a tarball of the PDF). Long elog, so here are the Highlights:
The DAC noise is not limiting us anywhere when the coil de-whitening is switched on.
So I don't understand the measured Dark Noise level, and it is limiting us at frequencies > 200Hz. Some busted electronics in the input signal chain? Or can the LSC demod daughter board gain of ~5 explain the observed noise?
Edit 1730 9 Oct: I had missed out the factor of 5 gain in the demod board in calculating the shot noise curve. Attachment #7 shows the corrected shot noise level. Explicitly:
, where is to convert shot noise in W to displacement units.
This seems to be limiting us from saturating the dark noise once the coil de-whitening is engaged. But lack of coherence means the mechanism is not re-injection of SRCL/PRCL sensing noise? Need to think about what this means / how we can mitigate it.
I've also made several changes to the NB code - will push to git once I finish cleaning stuff up, but it is now much faster to make these plots and see what's what.
There are no more double sided tape on this table.
Gabriele had prepared a C code implementation of his NN for MICH/PRCL state estimation. He had been trying to get it going on some of the machines in WB, but was unsuccessful. The version of RCG he was trying to compile and run the code on was rather dated so we decided to give it a whirl on our new RCG3.4 here at the 40m. Just noting down stuff we tried here:
All models have been reverted to their state prior to this test, and everything on the CDS_OVERVIEW MEDM screen is green now.
Looks to have worked this time around.
controls@fb1:~ 0$ sudo dd if=/dev/sda of=/dev/sdc bs=64K conv=noerror,sync
33554416+0 records in
33554416+0 records out
2199022206976 bytes (2.2 TB) copied, 55910.3 s, 39.3 MB/s
You have new mail in /var/mail/controls
I was able to mount all the partitions on the cloned disk. Will now try booting from this disk on the spare machine I am testing in the office area now. That'd be a "real" test of if this backup is useful in the event of a disk failure.
The 4TB HGST drives have arrived. I've started the FB1 dd backup process. Should take a day or so.
Steve, can you please connect this fan to the rack power and remove this extra power supply?
Re-arranged the DC bench supply on the shelf in the PSL enclosure, whose only purpose seems to be to supply 12V to a fan attached to the rear of the PSL NPRO controller. Seems to be a waste of space! The fan was momentarily disconnected but has since been reconnected and is spinning again.
I've located the Stanford Research FS725 Rb reference unit. The question is where to put it. This afternoon Steve and I put it inside the little electronics rack next to 1X3, but in hindsight, this probably isn't such a great place for a timing reference as there are a bunch of Sorensen power supplies in there (and presumably the accompanying harmonics from these switching supplies).
The unit itself was repaired in 2015, and powering it on, it locked to the internal reference within a few minutes as prescribed in the manual.
MC Autolocker was umnhappy because c1iool0 was unresponsive and hence it couldn't write to the "C1:IOO-MC_AUTOLOCK_BEAT" channel. I keyed the crate and IMC locked almost immediately. I'm moving this channel into the RTCDS model as we did for the IFO_STATE EPICS channel so that the autolocker isn't dependant on c1iool0 (which was the whole point of migrating the IFO-STATE variable anyways). I also commented out all of these channels in /cvs/cds/caltech/target/c1iool0/autolocker.db so that there aren't duplicate channels.
Eurocrate key turning reboots for c1susaux, c1auxex,c1auxey, c1iscaux, c1iscaux2 and c1aux. Usual precautions were taken for ITMX. Did burtrestore for c1iscaux andc1iscaux2 in order to restore the LSC PD whitening gains.
Un-related to this work: input pointing into PMC was tweaked as the PMC_REFL spot was pretty bright.
In the end I decided to access the available spare DAC channels via the C1ASS model - for this purpose, I added a namespace block "TEST" in the C1ASS simulink model, which is a SISO block. Inside is just a single CDS filter module. My idea is to use the EXC of this filter module to inject excitations for measuring various couplings. Rather than have a simple testpoint, we also have the option of adding in some filter shapes in the filter module which could possibly allow a more direct read-off of some coupling TF. Recompiling the model went smooth - there was a crash earlier in the day which required me to hard-reboot c1lsc (and also restart all models on c1sus and c1ioo but no reboots necessary for those machines).
Note that to get the newly added channels to show up in the channel lists in DTT/AWGGUI etc, you need to ssh into fb1 and restart the daqd processes via sudo systemctl restart daqd_*. If I remember right, it used to be enough to do telnet fb 8088 followed by shutdown. This is no longer sufficient.
It took me a while to get the DRMI locking going again. The model restarts earlier in the evening had changed a bunch of EPICS channel settings (and out config scripts don't catch all of these settings). In particular, I forgot to re-enable the x3 digital gain for the ITMs, BS and SRM (necessitated by removing an analog x3 gain on the de-whitening boards). I was hesitant to spend time re-adjusting all damping / oplev loop gains because if we change the series resistor on the coil driver board, we will have to do this again. I also didn't want this arbitrary FM to be enabled in the SDF safe.snap. But maybe it's worth doing it anyways - if nothing it'll be good practise.
Once I hunted down all the setting diffs and tweaked alignment, the DRMI locks were pretty robust.
I had hoped to make some of these TF measurements tonight. But I realized I needed to look up a bunch of stuff in manuals/datasheets, and think about these measurements a little. I wasn't sure if the DW/AI board could drive a signal over 40m of BNC cabling so I added an SR560 (DC coupled, gain=1, low noise mode, 50ohm output used) to buffer the output. The Marconi's external modulation input is high impedance (100k) but for the AOM driver we want 50ohm. For the Marconi, the external input accepts 1Vrms max, while for the AOM driver, we want to drive a signal between 0V and 1V at most.
The general measurement setup is schematically shown in Fig 1. Questions to address:
Am I missing something?
There are at least 5 free DAC channels (4 if you discount the one channel from these that I am hijacking) available in the 1Y2 electronics rack.
Jamie's nice wiring diagram shows the topology - the actual DAC card sits in 1Y3 inside the c1lsc expansion chassis (while the c1lsc frontend itself is in 1X4). The output of the DAC goes via SCSI to an interface box (D080303) and then to some dewhitening/AI boards (D000316). There are a total of 16 DAC channels available, out of which 8 are used for the TTs, 2 are used for the DAFI model, and one is labeleld "From c1ioo 1X2" (I don't know what this one is for). So I'm going to use some of these channels for measuring the coupling of oscillator noise and intensity noise to MICH in the DRMI lock.
The de-whitening/AI board seems to be old - it has 2x 800Hz Butterworth LPFs and no notch for the clock frequency, but maybe this doesn't matter for the tests I have in mind. The AI board available on 1X2 is more modern but routing the DAC channels from 1Y2 to it is going to be some work.
I'm going to add my testpoint to c1daf given that it seems to be the least critical model on c1lsc.
EDIT: testpoints added to c1daf don't show up in the list of available channels - there was some issue with this model while we were getting the new RTCDS going. So I'm moving my temporary testpoint to c1cal instead.
Disclaimer: Wrong calibration factors! See https://nodus.ligo.caltech.edu:8081/40m/13391
The factors were indeed enormously off. The correct table reads:
I did subtract a 'dark' frame from the images, though not in the sense of your point 1, just an exposure of identical duration with the laser turned off. This was mostly to reduce the effect of residual light, but given similar initial conditions would somewhat compensate for the offset that pre-existing charge and electronics noise put on the pixel values. The white field is of course a difference story.
I wonder how close we can get to a white field by putting a thin piece of paper in front of the camera without lenses and illuminate it from the other side. A problem is of course the coherence if we use a laser source... Or we scrap any sort of screen/paper and illuminate directly with a strongly divergent beam? Then there wouldn't be a specular pattern.
I'm not sure I understand your point about the 1.5V/A. Just to make sure we're talking about the same thing I made a crude drawing:
The PD sees plenty of light at all times, and the 1.5V/uW came from a comparative measurement PD<-->Ophir (which took the place of the CCD) while adjusting the power deflected with the AOM, so it doesn't have immediate connection to the conversion gain of silicon in this case. I can't remember the gain setting of the PD, but I believe it was 0dB, 20dB at most.
GV Oct 6: This coupling is probably not correct - Finesse outputs TF magnitude in units of W/W, and not W/RIN.
Since I was foiled (by lack of DAC) in my attempt to measure the coupling of laser intensity noise to MICH in the DRMI (no arms) configuration, I decided to try understanding the effect with a simulation.
For this purpose, I used my DRMI Finesse model - this had mirror positions tuned for locking and photodiode demod phases tuned to give a sensing matrix model that wasn't too far from an actual measurement (within factor of a few). So the model seems okay for a first pass at estimating this coupling.
Measuring transfer functions in Finesse is straightforward - use the fsig command to modulate some quantity (in this case the input beam intensity), and use the pd2 detector to demodulate the effect of this modulation at the port of interest (in this case AS55_Q).
**Note that to apply a modulation to an input beam (i.e. Laser) in Finesse, the keyword for the "type" argument given to fsig is "amp" and not "amplitude" as the manual would had me believe. In fact, there seem to be quite a few such caveats. The best way to figure this out is to go to the pykat installation directory, find the file components.py, and look for the fsig_name for the component of interest. It is also indicated in the same file, via the canFsig argument, if that property of the component can be modulated for transfer function measurements.
Attachment #1 shows the result of such a sweep.
To estimate what the actual contribution to the displacement noise is, I used the DQ-ed MC transmission (recorded at 1024Hz) from the DRMI lock, computed the ASD using scipy.signal.welch, divided by the nominal MC transmission of ~15,000 counts to convert to RIN/rtHz. The RIN was then multiplied by the above calculated coupling function, and divided by the sensing matrix element for AS55_Q (in units of W/m) to give the curve shown in Attachment #2. If we believe the simulation, then Laser Intensity Noise shouldn't be the limiting noise between 10Hz-1kHz.
I will of course measure the actual coupling and see how it lines up with Attachment #1 - would be a nice additional validation of the Finesse model. I will also try using the Finesse model to estimate some other coupling transfer functions (e.g. Laser Frequency Noise, Oscillator Noise).
The absence of evidence is not evidence of absence.
Going through some astronomy CCD calibration resources (-), I gather that there are in general 3 distinct types of correction that are applied:
The flat-field calibration seems to be the most complicated - the idea is to use a source of known radiance, and capture an image of this known radiance with the CCD. Then assuming we know the source radiance well enough, we can use some math to back out what the actual response function of individual pixels are. Then, for an actual image, we would divide by this response-map to get the actual image. There are a number of assumptions that go into this, such as:
I am not sure what error is incurred by ignoring 2 and 3 in the list at the beginning of this elog, perhaps this won't affect our ability to estimate the scattered power from the test-masses to within a factor of 2. But it may be worth it to do these additional calibration steps.
I also wonder what the uncertainty in the 1.5V/A number for the photodiode is (i.e. how much do we trust the Ophir power meter at low power levels?). The datasheet for the PDA100A says the transimpedance gain at 60dB gain is 1.5 MV/A (into high impedance load), and the Si responsivity at 1064nm is ~0.25A/W, so naively I would expect 0.375 V/uW which is ~factor of 4 lower. Is there a reason to trust one method over the other?
Also, are the calibration factor units correct? Jigyasa reported something like 0.5nW s / ct in her report.
The incident power can be calculated as Pin =CF*Total(Counts-DarkCounts)/ExposureTime.
This did the trick - I simply ran
sudo systemctl restart daqd_*
on FB1, and now all the CDS overview lights are green again.
I thought I had done this already, but I realize that I was supposed to restart the daqd processes on FB1 (which is where they are running) and not on c1ioo .
Thanks Jamie for the speedy resolution!
From page 21 of T1100625, DAQ status "0x2000" means that the channel list is out of sync between the front end and the daqd. This usually happens when you add channels to the model and don't restart the daqd processes, which sounds like it might be applicable here.
It looks like open-mx is loaded fine (via "rtcds lsmod"), even though the systemd unit is complaining. I think this is because the open-mx service is old style and is not intended for module loading/unloading with the new style systemd stuff.
I was trying to set up a DAC channel to interface with the AOM driver on the PSL table.
[4072817.132040] c1als: Failed to allocate DAC channel.
[4072817.132040] c1als: DAC local 0 global 16 channel 4 is already allocated.
[4072817.132040] c1als: Failed to allocate DAC channel.
[4072817.132040] c1als: DAC local 0 global 16 channel 5 is already allocated.
[4072817.132040] c1als: Failed to allocate DAC channel.
[4072817.132040] c1als: DAC local 0 global 16 channel 6 is already allocated.
[4072817.132040] c1als: Failed to allocate DAC channel.
[4072817.132040] c1als: DAC local 0 global 16 channel 7 is already allocated.
[4073325.317369] c1als: Setting stop_working_threads to 1
controls@c1ioo:~ 130$ sudo systemctl status mx
● open-mx.service - LSB: starts Open-MX driver
Loaded: loaded (/etc/init.d/open-mx)
Active: failed (Result: exit-code) since Tue 2017-10-03 00:27:32 UTC; 34min ago
Process: 29572 ExecStop=/etc/init.d/open-mx stop (code=exited, status=1/FAILURE)
Process: 32507 ExecStart=/etc/init.d/open-mx start (code=exited, status=1/FAILURE)
Oct 03 00:27:32 c1ioo systemd: Starting LSB: starts Open-MX driver...
Oct 03 00:27:32 c1ioo open-mx: Loading Open-MX driver (with ifnames=eth1 )
Oct 03 00:27:32 c1ioo open-mx: insmod: ERROR: could not insert module /opt/3.2.88-csp/open-mx-1.5.4/modules/3.2.88-csp/open-mx.ko: File exists
Oct 03 00:27:32 c1ioo systemd: open-mx.service: control process exited, code=exited status=1
Oct 03 00:27:32 c1ioo systemd: Failed to start LSB: starts Open-MX driver.
Oct 03 00:27:32 c1ioo systemd: Unit open-mx.service entered failed state.
The two acA640-120gm Basler GigE-Cams have been calibrated. I used the collimated output of a fiber that carried the auxiliary laser light from the PSL table. With a non-polarizing beam splitter some of the light was picked off onto a PD, and I modified the RF amplitude of the AOM drive signal to vary the power coming out of the fiber. The fiber output was directed at a white paper, which was placed 1.06m from the front of the lens tube assembly, which is where the focal plane is. Using the Pylon Viewer App I made sure that the entirety of the beam spot was imaged onto the CCD. Since the camera sensor is 1/4" across, I removed the camera from the lens tube and instead placed the Ophir power meter head at the position of the sensor and measured the power reported versus PD voltage, which turned out to be 1.5 V/uW.
The camera was put back in place and I used the Pypylon package Gautam had stumbled upon to sweep the exposure time from 100us to 10ms at different light power settings including no laser light at all for background subtraction, and rather than keeping the full bitmap data for O(100s) of images I recorded only the quantities
I performed this procedure for both the 152 and 153 cameras and plotted the pixel sum and the pixel max vs the exposure time. All the exposures were taken at a gain setting of 100, which is the smallest possible setting (out of 100-600). To obtain the calibration factor I use the input power Pin=75nW in the 'safe' region 1ms to 10ms where the pixel sum looks smooth and the CCD is reportedly not saturated.
BS connections and damping restored.
The first Faraday isolater rejected beam path from the NPRO is fixed.
The FB1 dd backup process seems to have finished too - but I got the following message:
dd: error writing ‘/dev/sdc’: No space left on device
30523666+0 records in
30523665+0 records out
2000398934016 bytes (2.0 TB) copied, 50865.1 s, 39.3 MB/s
Running lsblk shows the following:
controls@fb1:~ 32$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 23.5T 0 disk
└─sdb1 8:17 0 23.5T 0 part /frames
sda 8:0 0 2T 0 disk
├─sda1 8:1 0 476M 0 part /boot
├─sda2 8:2 0 18.6G 0 part /var
├─sda3 8:3 0 8.4G 0 part [SWAP]
└─sda4 8:4 0 2T 0 part /
sdc 8:32 0 1.8T 0 disk
├─sdc1 8:33 0 476M 0 part
├─sdc2 8:34 0 18.6G 0 part
├─sdc3 8:35 0 8.4G 0 part
└─sdc4 8:36 0 1.8T 0 part
While I am able to mount /dev/sdc1, I can't mount /dev/sdc4, for which I get the error message
controls@fb1:~ 0$ sudo mount /dev/sdc4 /mnt/HGSTbackup/
mount: wrong fs type, bad option, bad superblock on /dev/sdc4,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so.
Looking at dmesg, it looks like this error is related to the fact that we are trying to clone a 2TB disk onto a 1.8TB disk - it complains about block size exceeding device size.
sudo dd if=/dev/sda of=/dev/sdb bs=64K conv=noerror,sync
in a tmux session on nodus (as I did for chiara and FB1, latter backup is still running).
I've modified the __init.py__ file located at /ligo/apps/linux-x86_64/cdsutils-480/lib/python2.7/site-packages/cdsutils/__init__.py so that you can now simply import pyawg from cdsutils. On the control room workstations, iPython is set up such that cdsutils is automatically imported as "cds". Now this import also includes the pyawg stuff. So to use some pyawg function, you would just do (for example):
One could also explicitly do the import if cdsutils isn't automatically imported:
from cdsutils import awg
Linking this useful instructional elog from Chris here: https://nodus.ligo.caltech.edu:8081/Cryo_Lab/1748
? Why aren't you able to just import 'awg' directly? You shouldn't have to import it through cdsutils. Something must be funny with the config.
As Rana pointed out to me, one important fact to keep in mind w.r.t. DAC noise is that it can be non-linear. So the RMS of the DAC noise in a higher frequency band (say 60-100Hz) can be affected by the RMS of the requested DAC signal in some lower frequency band (say 10-20Hz). One test to see if this hypothesis can explain the difference @100Hz between the ITMX channels and BS channels I observed a couple of days ago is to see if the noise around 100Hz becomes lower when I enable a 20-40Hz bandstop in the digital signal chain.
The nodus backup too is now complete - however, I am unable to mount the backup disk anywhere. I tried on a couple of different machines (optimus, chiara and pianosa), but always get the same error:
mount: unknown filesystem type 'LVM2_member'
The disk itself is being recognized, and I can see the partitions when I run lsblk, but I can't get the disk to actually mount.
Doing a web-search, I came across a few blog posts that look like the problem can be resolved using the vgchange utility - but I am not sure what exactly this does so I am holding off on trying.
To clarify, I performed the cloning by running
After consulting with Jamie, we reached the conclusion that the reason why the root of FB1 is so huge is because of the way the RAID for /frames is setup. Based on my googling, I couldn't find a way to exclude the nfs stuff while doing a backup using dd, which isn't all that surprising because dd is supposed to make an exact replica of the disk being cloned, including any empty space. So we don't have that flexibility with dd. The advantage of using dd is that if it works, we have a plug-and-play clone of the boot disk and root filesystem which we can use in the event of a hard-disk failure.
This is not quite right. First of all, /frames is not NFS. It's a mount of a local filesystem that happens to be on a RAID. Second, the frames RAID is mounted at /frames. If you do a dd of the underlying block device (in this case /dev/sda*, you're not going to copy anything that's mounted on top of it.
What i was saying about /frames is that I believe there is data in the underlying directory /frames that the frames RAID is mounted on top of. In order to not get that in the copy of /dev/sda4 you would need to unmount the frames RAID from /frames, and delete everything from the /frames directory. This would not harm the frames RAID at all.
But it doesn't really matter because the backup disk has space to cover the whole thing so just don't worry about it. Just dd /dev/sda to the backup disk and you'll just be copying the root filesystem, which is what we want.
I am trying option 3 now. dd however does requrie that the destination drive size be >= source drive size - I'm not sure if this is true for the HGST drives. lsblk suggests that the drive size is 1.8TB, while the boot disk, /dev/sda, is 2TB. Let's see if it works.
Backup of chiara is done. I checked that I could mount the external drive at /mnt and access the files. We should still do a check of trying to boot from the LaCie backup disk, need another computer for that.
nodus backup is still not complete according to the console - there is no progress indicator so we just have to wait I guess.
We also wanted to do a backup of the root of FB1 - but I'm not sure if dd will work with the external hard drive, because I think it requires the backup disk size (for us, 1TB) to be >= origin disk size (which on FB1, according to df -h, is 2TB). Unsure why the root filesystem of FB is so big, I'm checking with Jamie what we expect it to be. Anyways we have also acquired 2TB HGST SATA drives, which I will use if the LaCie disks aren't an option.
Since you're monitoring two channels simultaneously, you could try subtracting them, as an alternative to carving out bandstops.
Subtraction can conceal certain annoying effects (like numerical noise or level crossing glitches) that remain coherent for two identical outputs. It might be worth experimenting with a differential offset or sinusoid, to try to break up that kind of coherence if it exists.
Attachment #1 is a sketch of the proposed setup to measure the PM response of the EX NPRO. Previously, this measurement was done via PLL. In this approach, we will need to calibrate the DFD output into units of phase, in order to calibrate the transfer function measurement into rad/V. The idea is to repeat the same measurement technique used for the AM - take ~50 1 average measurements with the AG4395, and look at the statistics.
Some more notes:
Attachment #1: Summary of results of measurements made on Friday. There is a lot in this plot, here is a breakdown:
Data + code for this plot will be attached later.
Attachment #1: Result of AM sweeps with EX laser crystal at nominal operating temperature ~ 31.75 C.
Attachment #2: Tarball of data for Attachment #1.
Attachment #3: Result of AM sweeps with EX laser crystal at higher operating temperature ~ 40.95 C.
Attachment #4: Tarball of data for Attachment #2.
I configured the remaining GigE-Camera to work on the 40m network. We currently have 3 operational Basler cameras:
The 120gm's have been assigned the IPs 192.168.113.152 (was already configured) and 192.168.113.153 (freshly configured) and have been labeled accordingly. Note that it was not necessary to connect the out-of-the-box camera directly to a dedicated ethernet adapter whose IP was set manually to 169.254.0.XXX as pointed out in earlier posts - a few seconds after connecting the camera to the control room switch (with PoE adapter to power it) the camera showed up in the configuration software tool which is launched via
and can be assigned a corrected, static IP.
We have a plethora of 2" tubes for the lens assembly, but not a great variety of focal lengths for 2" lenses. Present with the camera gear were two f=250 mm and one f=150 mm 2" lenses with a NIR broadband AR coating
To determine the lens positions relativ to the sensor I assumed that the camera we're setting up looks at its test mass from a distance of 1m. Using the two available focal lengths we can look for solutions which have reasonable lens separations <~10cm and suitable magnification. We primarily want to image the central mirror area onto a 1/4" sized sensor, which can be achieved with a magnification of ~1/8.
I chose a lens separation of 6cm, which gives a theoretical magnification of -.12 and a sensor-lens 2 distance of 7.95 cm. I placed the lenses accordingly in the tubes and checked the focusing with Gautam's help:
It's pretty close to what we would expect. We will do the calibration using the auxiliary laser on the PSL table. For this I temporarily routed a fiber from the PSL enclosure to the SP table. Since the main cable hole is sort of cramped it's going in through a gap near the ceiling instead.
The Fiber ALS box has been installed on the existing shelf on the PSL table. We had to re-arrange some existing cabling to make this possible, but the end result seems okay (to me). The box lid was also re-installed.
Some stuff that still needs to be fixed:
Beat spectrum post changes to follow.
Is it better to mount the box in the PSL under the existing shelf, or in a nearby PSL rack?
Further characterization needs to be done, but the results of this test are encouraging. If we are able to get this kind of out of loop ALS noise with the IR beat, perhaps we can avoid having to frequently fine-tune the green beat alignment on the PSL table. It would also be ideal to mount this whole 1U setup in an electronics rack instead of leaving it on the PSL table
I first initialized the drives by hooking them up to my computer and running the setup.app file. After this, plugging the drive into the respective machine and running lsblk, I was able to see the mount point of the external drive. To actually initialize the backup, I ran the following command from a tmux session called ddBackupLaCie:
sudo dd if=/dev/sda of=/dev/sdb bs=64K conv=noerror,sync
Here, /dev/sda is the disk with the root filesystem, and /dev/sdb is the external hard-drive. The installed version of dd is 8.13, and from version 8.21 onwards, there is a progress flag available, but I didn't want to go through the exercise of upgrading coreutils on multiple machines, so we just have to wait till the backup finishes.
Gabriele reported problems with the nds2 server again. I restarted it again.
update: had to do it again at 1730 today - unclear why nds2 is so flaky. Log files don't suggest anything obvious to me...
I was unable to download data using nds2. Gabriele had reported similar problems a week ago but I hadn't followed up on this.
I repeated steps 5-7 from elog 13161, and now it seems that I can get data from the nds2 servers again. Unclear why the nds2 server had to be restarted. I wonder if this is somehow related to the mysterious acromag EPICS server tmux session dropout.
I had to do a reboot + burt restore of c1psl today. It was unresponsive and I couldn't get the PMC to lock. I also had to slightly realign the PMC, and the IMC was too misaligned for the autolocker to catch lock. Adjusting it manually, it was predominantly MC1 PIT that was off. The YARM locked on a 10 mode and had to be aligned manually as well.
I left a script running on Donnatella that tilts ETMX and thus moves the beam on ITMX. I'm monitoring the transmitted power to evaluate sane thresholds for the demodulation offsets in a lossmap measurement. The script will return the IFO to normal after it is done and will take <2 hours to complete (no real clue, but there's no way it takes longer than that for ~50 datapoints).
I have made several changes to Craig's script for better pythonism. Its more robust with different libraries and syntaxes and makes a tarball by default (w/o a command line flag). These kinds of general util scripts will be going into a general use folder in the git.ligo.org/40m/ team area so that it can be used throughout the LSC.
I don't think we need/want a coherence calculation, so I have not included it. Usually, we use coherence to estimate the uncertainty, and here we are just plotting it directly from the dist of the sweeps so coherence seems superfluous.
I've been working on setting up some scripts for measuring the DAC noise.
In all the DRMI noise budgets I've posted, the coil-driver noise contribution has been based on this measurement, which could be improved in a couple of ways:
I only managed to get in measurements for the BS and ITMX today. ITMY to be measured later, and data/analysis to follow.
The ITMX and BS alignments have been restored after this work in case anyone else wants to work with the IFO.
Some slow machine reboots were required today - c1susaux was down, and later, the MC autolocker got stuck because of c1iool0 being unresponsive. I thought we had removed all dependency of the autolocker on c1iool0 when we moved the "IFO-STATE" EPICS variable to the c1ioo model, but clearly there is still some dependancy. To be investigated.
We laid out a 45m long BNC cable from the LSC rack to the IOO rack via overhead cable trays. There is ~5m excess length on either side, which have been coiled up and cable-tied for now. The ends are labelled "TO LSC RACK" and "TO IOO RACK" on the appropriate ends. This is to facilitate hooking up the output of the DFD for making a PM measurement of the AUX X laser. There is already a long cable that runs from the IOO rack to the X end.