40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 325 of 335  Not logged in ELOG logo
ID Date Author Type Category Subject
  537   Wed Jun 18 00:19:29 2008 robUpdatePSLMOPA trend
15 day trend of MOPA channels. The NPRO temperature fluctations are real, and causing the PMC to consistently run up against its rails. The cause of the temperature fluctations is unknown. This, combined with the MZ glitches and Miller kicking off DC power supplies is making locking rather tetchy tonight. Hopefully Yoichi will find the problem with the laser and fix it by tomorrow night.
Attachment 1: MOPAtrend.png
  536   Tue Jun 17 22:00:53 2008 JohnHowToPSLProblems turning MZ servo on/off
We were unable to toggle the MZ servo on/off (Blank/Normal) from MEDM. Pushing on the Xycom board and cables changed the fault from constant to intermittent. At least one lock loss has been caused by a MZ glitch.
  535   Mon Jun 16 18:26:01 2008 Max JonesUpdateComputer Scripts / ProgramsNoise Budget Changes
In the directory cvs/cds/caltech/NB the following changes were made:

I created temporary files in ReferenceData for the C1 by copying and renaming the corresponding H1 files.
- C1_SRD_Disp.txt
- C1IFOparams.m
- C1_NoiseParams.m

In getmultichan.m I added a C1 case.

In NoiseBudget.m I added a C1 case with modified sources array to include only DARM and Seismic

I appreciate and suggestions. Max.

  534   Fri Jun 13 11:17:25 2008 YoichiUpdatePSLPMC transmittance at high power
We received a new cable for the Scientech calorimeter. So I measured the transmittance of the PMC at higher power.

Input power = 2.298W
Output power = 1.364W
Transmittance = 59%

The input power to the PMC was measured between the two mode matching lenses by the calorimeter.
2.298W looks a bit too low. Actually, the calibrated monitor PD on the MEDM screen shows about 3W output from MOPA.
So we (me and Steve) measured the power right after the PBS after the periscope from MOPA with the HWP set to maximize the transmission of the PBS.
It was 2.77W. According to Steve's previous measurement, the first mirror of the periscope transmits about 200mW of the incoming light to the monitor PD. So the actual output of the MOPA is about 2.97W, which is consistent with the monitor PD reading.
The aperture of the EOM for the PMC control is glowing a lot. We suspect this is the main cause of the loss (from 2.77W to 2.298W).
We may want to re-align the EOM.

The output light from the PMC was picked off by a glass slide. The reflectance of the glass slide was measured first at a lower power (input 98mW, reflected power 1.58mW). Assuming that the reflectance is the same for the higher power, I turned up the input power to the PMC. This time, the picked off power was 22.45mW. This means the actual output power is 98/1.58*22.45=1364mW. The glass slide was kept at the same angle through out the measurement.
The measurement of the output power was done by the Ophir power meter. So calibration difference between the Ophir and the calorimeter may introduce some error.
  533   Thu Jun 12 15:55:15 2008 robUpdateLockingreport

Rob: Awesome figure. As you can imagine, I have lots of questions, and hope that you will consider this figure to be the beginning, leading to ever-more detailed versions. But for now, I just want to ask whether you understand *what* is twitchy, and what the twitchiness does to prevent you from taking this further?

I definitely don't understand what's twitchy, but I have suspicions. Tonight we'll try to start by revisiting the other loops (the non-CARM loops) and see how they're dealing with the changing power levels. It may be that the DARM loop is going unstable due to gain variations (due to either increasing power or to rotation of demod phase) or it could be the PODD (or SPOB) saturating with increased power in the recycling cavity. I just hope the glitchiness doesn't have a digital origin.
  532   Thu Jun 12 15:09:33 2008 alanUpdateLockingreport
Rob: Awesome figure. As you can imagine, I have lots of questions, and hope that you will consider this figure to be the beginning, leading to ever-more detailed versions. But for now, I just want to ask whether you understand *what* is twitchy, and what the twitchiness does to prevent you from taking this further?
  531   Thu Jun 12 01:51:23 2008 robUpdateLockingreport
rob, john

We've been working (nights) on getting the IFO locked this week. There's been fairly steady incremental progress each night, and tonight we managed to control CARM(MCL) using PO-DC, with the CARM(AO) path also on PO-DC. In the past, reaching this state has usually meant we're home free, as we could just crank the gain on the common mode servo and merrily reduce the CARM offset. Tonight, however, this state has been very twitchy, and efforts to ramp up the gain have been unsuccessful.

I've attached a diagram which I hope makes clear where we are in the stages of lock acquisition.
Attachment 1: lock_control_sequence.png
  530   Wed Jun 11 15:30:55 2008 josephbConfigurationCamerasGC1280
The trial use GC1280 has arrived. This is a higher resolution CMOS camera (similar to the GC750). Other than higher resolution, it has a piece of glass covering and protecting the sensor as opposed to a plastic piece as used in the GC750. This may explain the reduced sensitivity to 1064nm light that the camera seems to exhibit. For example, the image averages presented here required a 60,000 microsecond exposure time, compared to 1000-3000 microseconds for similar images from the GC750. This is an inexact comparison, and the actual sensitivity difference will be determined once we have identical beams on both cameras.

The attached pdfs (same image, different angles of view) are from 200 averaged images looking at 1064nm laser light scattering from a piece of paper. The important thing to note is there doesn't seem to be any definite structure, as was seen in the GC750 scatter images.

One possibility is that too much power is reaching the CMOS detector, penetrating, and then reflecting back to the back side of the detector. Lower power and higher exposure times may avoid this problem, and the glass of the GC1280 is simply cutting down on the amount passing through.

This theory will be tested either this evening or tomorrow morning, by reducing the power on the GC750 to the point at which it needs to be exposed for 60,000 microseconds to get a decent image.

The other possibility is that the GC750 was damaged at some point by too much incident power, although its unclear what kind of failure mode would generate the images we have seen recently from the GC750.
Attachment 1: GC1280_60000E_scatter_2d.pdf
Attachment 2: GC1280_60000E_scatter_3d.pdf
  529   Wed Jun 11 11:45:25 2008 steveUpdatePSLss trap works
The trap works well at 3 W level. No back reflected beam coming out of the trap on low power
sensing card level. The back scattering was not measured. The trap is insensitive to small pointing variations.
The SS surface did not show any visible degradation after 16 hrs of 3w exposure at elliptical beam size 4x8 mm

It is ready to be placed into the 35 W beam.
Attachment 1: P1020534.png
Attachment 2: P1020533.png
  528   Tue Jun 10 08:37:18 2008 steveUpdatePSLbeam trap is being tested
High power beam trap is being tested just west of FSS area on psl enclosure.

When the pmc is operating at low power that means that the rest of the 3W is going into the
circular SS trap.

Please beware of the high power beam trap test
Attachment 1: trapss3w.png
  527   Mon Jun 9 17:57:59 2008 YoichiConfigurationPSLPMC input power backed to the original
I rotated back the HWP before the PBS to restore the input laser power to the PMC.
Now the reading of PSL-PMC_PMCTRANSPD is 2.7.
  526   Mon Jun 9 17:32:14 2008 YoichiConfigurationPSLPMC transmittance
I checked the current PMC transmissivity at a low power.
The input laser power to the PMC was reduced to 75mW by rotating the HWP in front of the PBS.
In this configuration, the output power from the PMC was 50mW. So the transmittance is about 66%.
The reading of C1:PSL-PMC_PMCTRANSPD is now 0.1 whereas it was 2.7 before turning the power down.

I will check the transmittance at a higher power when I get the cable for the 35W calorie meter, which is missing now.
  525   Fri Jun 6 16:47:04 2008 josephbConfigurationCameras GC650 scatter images of 1064nm light
Took images similar to the scattered light images from earlier, except with the CCD GC650 camera. The first three attached plots are an average of all 200 images, an average of the first 100 and then an average of the last 100 images.

They show no definite structure. The big red blob which changes with time may be a brighter reflection, although it virtually the same type of setup as the GC750 images.

To do this properly, I should grab a short focal length lens and simply blow up the beam to a size greater than the detector area and simply fix both cameras looking into.

The last set of plots are mean and standard deviation plots from a previous set of runs on 5/29/08 with the GC750 and GC650 running at the same time. The GC650 was receiving approximately 33% of the total power and GC750 was receiving 66% (in otherwords a factor of 2 more).
Attachment 1: GC650_scatter_200.pdf
Attachment 2: GC650_scatter_100a.pdf
Attachment 3: GC650_scatter_100b.pdf
  524   Fri Jun 6 16:10:51 2008 steveUpdatePSLHEPA filters are running at 100%
The psl HEPA filters were turned up to run at 100% to accommodate beam trap work on Tuesday, June 3, 2008
  523   Fri Jun 6 15:56:00 2008 steveBureaucracySAFETYYoichi received safety training
Yoichi Aso received 40m specific safety training.
  522   Fri Jun 6 11:19:13 2008 CarynSummaryPEMFiltering MC_L and MC_F with PEM:ACC and microphone
Tried to filter MC_L and MC_F with acc/seis data and microphone data using wiener filter (levinson)

-Used get_mic_data.m and miso_filter_lev.m to make SISO filter for 2 minutes of IOO-MC_F data. Used PEM-AS_MIC signal as noise input data. Filters calculated at initial time were applied to later data in 1 hour intervals.
-microphone filter did not seem to filter MC_F very well in high frequency range using this filtering procedure.
-residual is larger than est (see MC_F pdf)
-Used do_all_time_lev.m to make graph of max(rms(residual)) to N(order) for different times.(note for each N, filter was calculated for initial time and then applied to data at other times).
-relation of max(rms(residual)) to N(order) is time sensitive (note-on graph, time interval is 1hour) (see MC_F pdf)
-Presumably, max(rms(residual)) should decrease as N increases and increase as time increases since the filter probably becomes worse with time. I think the reason this isn't always true in this case is that the max(rms(residual)) corresponds to a peak (possibly a 60Hz multiple) and the wiener filter isn't filtering out that peak very well.

-Used get_z_data.m and miso_filter_lev.m to make MISO filter for 2 minutes of IOO-MC_L used the following signals as noise input data
-Filter was applied to later data in 2hour intervals.
-Used do_all_time_lev.m to make graph of max(rms(residual)) to N(order) for different times.(note for each N, filter was calculated for initial time and then applied to data at other times).
-acc/seis filter seemed to filter MC_L OK for 128,256,512Hz srates. 64 Hz wasn't ok for certain N's after a period of time.
-residual is smaller than est for srates not 64Hz (see MC_L pdf)
-residual is larger than est for 64Hz at N=1448 for later times (see MC_L pdf)
-relation of max(rms(residual)) to N is not as time sensitive for higher sample rates (note-on graph, time interval is 2hours) (see MC_L pdf). Perhaps the levinson 64Hz sample rate filter doesn't do as well as time passes for these signals. When the filter didn't do well, the max(rms(residual)) seemed to increase with N.
-For 512Hz sample rate filter the max(rms(residual)) decreased with time. If the max(rms(residual)) were an indication of filter performance, it would mean that the 512Hz filter calculated at the initial time was performing better later as hours passed by! Perhaps max(rms(residual)) isn't always great at indicating filter performance.

Programming notes
-I had to modify values in do_all_time_lev.m to get the program to loop over the srates,N's,times I wanted
-do_all_time_lev.m is not as clean as do_all_lev.m
-for making the plots do_all_lev.m (which isn't really a procedure and is messy) has some examples of how to plot things from do_all_time_lev.m.
Attachment 1: MC_F.pdf
MC_F.pdf MC_F.pdf MC_F.pdf
Attachment 2: MC_L.pdf
MC_L.pdf MC_L.pdf MC_L.pdf MC_L.pdf MC_L.pdf MC_L.pdf MC_L.pdf MC_L.pdf
Attachment 3: miso_filter_lev.m
function [s] = miso_filter_lev(N,srate,rat,z)
%MISO_FILTER_LEV(N,srate,z) uses miso_firlev to get levinson
%   FIR Wiener filter of order N-1, using impulse response of 
%   N/srate. z is a structure gotten from the get_data function. 
%   z(end) is the signal which is filtered using z(i) for all i.
%   'rat' is the fraction of z which will be put into filter
%   funtion. The data from z is downsampled using srate and 
%   detrended. Let rat=1. I don't have that part working yet.

... 107 more lines ...
Attachment 4: get_mic_data.m
%get_mic_data gets data for'C1:IOO-MC_F', 'C1:PEM-AS_MIC,
% Example:  z = get_mic_data('now',120,60)
%  start time is 't- d_t' so  d_t should be given in seconds. t should be given
%  as a number like 893714452. d is duration in seconds. get_mic_data saves
%  data to a file in current directory named 'temp_mic'. You will be asked to
%  save file as 'mic_(start_time)_(duration)'.

duration = d;

... 32 more lines ...
Attachment 5: do_all_time_lev.m
function[r] = do_all_time_lev(n,t0,int,duration,N,srate,rat,order,time,MC_L,MC_F,sample_rate)
%do_all_time explores how filter performance changes with time, sample rate,
%and order of filter. Outputs data,noise estimate, structure of max
%rms error and other info. It uses get_data, miso_filter_lev, and miso_filter_int and retrives
%MC_Ldata or MC_Fdata for multiple times, calculates a miso_filter for initial-time data
%file, applies filter to the other data files, and keeps track of the...
%max(rms(residual)) for each filter. n+1 is number of data files. int is time interval between
%data files, t0 is start time, duration is duration of each data file, srate
%is the sample rate for which filter is calculated, n_N is number of orders
%of the filter you want the program to calculate,int_N is interval by which N
... 215 more lines ...
Attachment 6: do_all_lev.m
function[r] = do_all_lev(n,t0,int,duration,n_N,int_N,n_srate,int_srate,rat,MC_L,MC_F)
%do_all_lev explores how filter performance changes with time, sample rate,
%and order of filter. Outputs data,noise estimate, structure of max
%rms error and other info. It uses get_data, miso_filter_lev, and miso_filter_int and retrives
%MC_Ldata or MC_Fdata for multiple times, calculates a miso_filter for initial-time data
%file, applies filter to the other data files, and graphs the rms of the cost
%function vs time. n+1 is number of data files. int is time interval between
%data files, t0 is start time, duration is duration of each data file, srate
%is the sample rate for which filter is calculated, n_N is number of orders
%of the filter you want the program to calculate,int_N is interval by which N
... 283 more lines ...
Attachment 7: do_all_plot.m
function[r] = do_all_plot(r,x,v)
 %do_all_plot plots variables contained in r(structure from
 %do_all_time_lev).Plots error(r.B.y) vs x. x can be
 %'s'(srate),'N'(order),'t'(time),'p'(impulse response). v can be 's','N','t'. 
 %example: do_all_plot(r,'s','t') makes a plot of error vs srate for
 %different times.


... 388 more lines ...
Attachment 8: miso_filter_int.m
function [s] = miso_filter_int(s,y)
%miso_filter_int inputs a filter and a structure array of data sets y, applies filter to data, and
%outputs a structure with fields: ppos(signal frequ spectrum),perr(cost
%function frequ spectrum),pest(signal estimate frequency
%spectrum),f(frequency),target(signal),est_darm(noise estimate),t(time).
%data file for which filter has been calculated is s (obtained using miso_filter). 
%y consists of data structures which will be filtered using
%filter from s. Then the power spectrum of the difference between signal and filtered-data is
%graphed for all the data files of y for comparison too see how well filter performs
%over time. Note if you want to create a y, take z1,z2,z3,etc. structures
... 120 more lines ...
  521   Thu Jun 5 13:35:23 2008 josephbConfigurationCamerasGC750 looking at 1064nm scattered light
I've taken 200 images of the GC750 (CMOS) camera while holding it by hand up to a beam card (also held by hand) in the path of ~5mW of beam power. I then averaged the images to produce the fourth attached plot.

Rob has pointed out the image looks a lot like PCB traces. So perhaps we're seeing the electronics behind the CMOS sensor?

I repeated the same experiment with HeNe laser light (again scattered off a card). These show none of the detailed structure (just what looks to be a large reflection from the card moving around depending on how steady my hand was). These are the first 3 attached plots. So only 1064nm light so far sees these features.

As a possible solution, I did a quick and dirty calibration by dividing a previous PSL output beam by the 1064 average scatter light values. These produce the last attached pdf (with multiple images). The original uncalibrated image is on top, while the very simply calibrated image is on the bottom of each plot.

It seems as the effect may be power dependent (which could still be calibrated properly, but would take a bit more effort than simply dividing), as determined by looking at the edges of the calibrated plot.
Attachment 1: GC750_HeNe_scatter_avg.pdf
Attachment 2: GC750_HeNe_scatter_avg2.pdf
Attachment 3: GC750_HeNe_scatter_avg3.pdf
Attachment 4: GC750_scatter_avg.pdf
Attachment 5: GC750_nitrogen_white.pdf
GC750_nitrogen_white.pdf GC750_nitrogen_white.pdf GC750_nitrogen_white.pdf GC750_nitrogen_white.pdf GC750_nitrogen_white.pdf GC750_nitrogen_white.pdf GC750_nitrogen_white.pdf
  520   Thu Jun 5 10:46:26 2008 josephbConfigurationCamerasApproximately uniform reflected white light
In an attempt to investigate the structures seen in previous images for the GC750, I aimed it at a relatively clean section of gray table top roughly a cm or two from the surface and took images (without a lens). As I was holding this with my hand, the angle wasn't completely even with the table, and thus there's a gradient of light in the pictures. However, one should in principle be able to pick out features (such as a circular spot with less sensitivity), but these do not show up.

In my mind, these images seem to indicate the electronics are fine, and suggest that the CMOS or CCD detectors themselves are undamaged (at least in regards to white light, as opposed to 1064nm). An issue with the plastic cap (protective piece) may be the culprit, or perhaps a tiny bit of dust, which the incoherent light from all angles goes around efficiently?

Will try blowing the cameras with clean nitrogen today and see if that removes or changes the circular structure we have seen.
Attachment 1: GC650_white_light.pdf
Attachment 2: GC750_white_light.pdf
  519   Wed Jun 4 16:57:12 2008 josephbConfigurationCamerasDark images from cameras (electronics noise measurement)
The attached pdfs are 1 second and 1 millisecond long integrations from the GC650 and GC750 cameras with a cap in place - i.e. no light.

They include the mean and standard deviation values.

The single bright pixel in the 1 second long exposure image for the GC650 seems to be a real effect. Multiple images taken show the same bright pixel (although with slightly varying amplitudes).

The last pdf is a zoom in on the z-axis of the first pdf (i.e. GC650 /w 1 sec exposure time).

I'm not really sure what to make of the mean remaining virtually fixed for the different integration times for both cameras. I guess 0 is simply offset, but doesn't result in any runaway integrations in general. Although there are certainly some stronger pixels in the long exposures when compared to the short exposures.

Its interesting to note the standard deviation actually drops from the long exposure to the short exposure, possibly influenced by certain pixels which seem to grow with time.

The one with the least variation from its "zero" was the 1 millisecond GC750 dark image.
Attachment 1: GC650_1sec_dark.pdf
Attachment 2: GC650_1msec_dark.pdf
Attachment 3: GC750_1sec_dark.pdf
Attachment 4: GC750_1msec_dark.pdf
Attachment 5: GC650_1sec_dark_zoom.pdf
  518   Wed Jun 4 16:25:06 2008 CarynSummaryPEMmicrophone moved
The microphone 'C1:PEM-AS_MIC' has been moved right a bit. This change didn't seem to have much effect on filtering the 'C1:IOO-MC_L' signal, at least not compared to how the filter changes with time. Also used microphone data to filter MC_L data using firwiener filter/levinson. The N(order) and sample rate were varied to see how the filter changed. Attached are graphs of the max(rms(noise_estimate)) vs N or IR for varying srate. Note that filtered_signal=signal-noise_estimate. So, the larger the noise_estimate, the more the filter subtracts from the signal.
Green-filtered signal
blue-noise estimate
red-MC_L signal
note decreasing sample rate is more effective than increasing N (higher N takes more time to compute)
note sample rate doesn't change the max(rms(noise_estimate)) very much if impulse response time remains constant
note the 64hz, N=7000 (impulse response about 110s) filter is a better filter than the 512Hz, N=7000(impulse response about 14s)
Attachment 1: 1_MC_L.pdf
1_MC_L.pdf 1_MC_L.pdf 1_MC_L.pdf 1_MC_L.pdf
  517   Wed Jun 4 13:46:42 2008 josephbConfigurationCamerasChanging incident angle images
Attached are images from the GC650 and GC750 when the incident angle was varied from 0 tilt (normal incidence) to 5,10, and 20 degrees. Each time the beam was realigned via the last turning mirror to be on roughly the same spot. This light was a pickoff of the PSL table light just before it leaves the table.

Images include the raw data, fit to the data, residual normalized by peak power "w(1)", and normalized by the individual bin power.

The first pdf includes 0 degrees (normal) and ~5 degrees of tilt for the GC650 (CCD) camera.

The second pdf includes ~10 and ~20 degrees of tilt images for the GC650 (CCD) camera.

The third pdf includes 0 and ~5 degrees of tilt for the GC750 (CMOS) camera.

The fourth pdf includes ~10 and ~20 degrees of tilt for the GC750 (CMOS) camera.

Things to note:
1) GC750 camera seems to have a structure on the camera itself, somewhat circular in nature. One possible explanation is the camera was damage at a previous juncture due to too much light. Need to check earlier images for this problem.
2) GC650 has "bands" which change direction and thickness with angle. Also at higher incidence angle, the sensitivity seems to drop (unlike the GC750 where overall power level seems to stay constant with increasing angle of incidence).
3) GC650 seems to have a higher noise floor,seen from the last plot of each pdf (where each pixel of the residual is normalized by the power in the corresponding pixel of the fit).
Attachment 1: GC650_0dg_5dg.pdf
GC650_0dg_5dg.pdf GC650_0dg_5dg.pdf GC650_0dg_5dg.pdf GC650_0dg_5dg.pdf GC650_0dg_5dg.pdf GC650_0dg_5dg.pdf GC650_0dg_5dg.pdf
Attachment 2: GC650_10dg_20dg.pdf
GC650_10dg_20dg.pdf GC650_10dg_20dg.pdf GC650_10dg_20dg.pdf GC650_10dg_20dg.pdf GC650_10dg_20dg.pdf GC650_10dg_20dg.pdf GC650_10dg_20dg.pdf
Attachment 3: GC750_0dg_5dg.pdf
GC750_0dg_5dg.pdf GC750_0dg_5dg.pdf GC750_0dg_5dg.pdf GC750_0dg_5dg.pdf GC750_0dg_5dg.pdf GC750_0dg_5dg.pdf GC750_0dg_5dg.pdf
Attachment 4: GC750_10dg_20dg.pdf
GC750_10dg_20dg.pdf GC750_10dg_20dg.pdf GC750_10dg_20dg.pdf GC750_10dg_20dg.pdf GC750_10dg_20dg.pdf GC750_10dg_20dg.pdf GC750_10dg_20dg.pdf
  516   Wed Jun 4 10:18:52 2008 steveUpdatePSLwedged SS beam trap
I moved the SS trap over to the psl table.
Texas super # 8 was used from the large shipment.
TXs#8 scattering measured as before, meaning the polishing is good.

Go's squeezing power pick up 350 mW was used.
I made two ~30 degrees wedge traps using 6" x 4" and 12" x 4" SS 0.039" thick
with copper backing of similar size.

There was too much scattering and I could not minimize them all.
It is very helpful to have so much space on the psl table.
It shows more of the weakness of this kind of trap.
I did not dare to turn up the power.
Attachment 1: trap1.png
Attachment 2: trap2.png
  515   Tue Jun 3 12:33:36 2008 AndreyUpdateCamerasAndrey, Josephb

Continuing our work with cameras,

1) we removed both cameras from their places on Monday afternoon, and were taking the beam-scans with a special equipment (see elog-entry 511) from Bridge bld.,

2) and on Tuesday morning we putted back the GC-750 camera into the transmitted beam path, camera GC-650 into the reflected beam path. We plan to compare the images from the "reflection camera" for several different angles of tilt of the camera.
  514   Tue Jun 3 10:40:27 2008 tobinConfigurationComputersnew dataviewer
Alex let me know the secret location of the latest dataviewer executable for Linux. It is:


If your linux dataviewer on linux2 has the "year field not filled in" bug, you should download this into /usr/local/bin/dc3 (after making a backup of that file).

It looks like there's no dataviewer installed on rosalba yet. We should figure out a better directory layout for the linux machines; currently dataviewer is installed locally on linux2. It should be in /cvs/cds/caltech/apps/linux/something so that all the linux machines see the same installation.
  513   Tue Jun 3 10:19:45 2008 tobinConfigurationComputersbig machine
Several of us transported the big new awesome Sun box from Bridge over to
the 40m last week. If I recall correctly, it's a SunFire X4600 with
something like sixteen 64-bit AMD processor cores at 2.8 GHz. It sounds
like a jet engine when it starts up (before the cooling fans are throttled
back) and has four power supplies (each with its own connection
to the wall). It has slick removable hard disks and fan units too. Our
working name for it is "megatron".

Anyway. It came with two hard disks, one with Solaris 10 installed. I took
the other hard disk over to Alex, who copied a Realtime Linux installation
onto it. Alex says it boots and runs fine.

It remains for you guys to install the machine onto rails and install the
whole thing into a rack. Before it goes into service as a realtime control
machine, you might as well install Matlab on it and do some heavy-duty

  512   Tue Jun 3 02:15:29 2008 AndreySummaryCamerasFitting results

There have been a lot of work going on related to the processing of images captured by the cameras GC-650 and GC-750 recently.

In the end of the week of May 30 Joseph and me (Andrey) installed the two cameras capturing the images of the pick-off of the main beam on the PSL optical table. The cameras are located after the picked-off beam going towards the "PSL position QPD", after the 33-66 beamsplitter (33% of reflection and 66% of transmission).

Initially (on May 30) the GC-650 camera was taking the images of reflected beam, while the camera GC-750 was taking images of transmitted beam. On Monday June 2 we switched the positions of the cameras, so GC-650 appeared to be on the path of the transmitted beam and GC-750 on the path of the reflected beam.

I (Andrey Rodionov) was able in the weekend to succeed in writing a Matlab program that performs the two-dimensional Gaussian fitting of the captured images, and I used that program to fit the images from the cameras.

The program fits the camera data by a two-dimensional Gaussian surface:

Z = A * exp[ - 2 * (X - X_Shift)^2 / (Waist_X)^2 ] * exp[ - 2 * (Y - Y_Shift)^2 / (Waist_Y)^2 ] + CONST_Shift,

where A, X_Shift, Waist_X, Y_Shift, Waist_Y, CONST_Shift are 6 parameters of the fit.

Attached are the pdf-files showing the results: images taken with our cameras, the 2-dimensional Gaussian fit for these images and the surfaces of residuals. Residuals are differences between the exact beam profile and the result of fitting. In normalized version of residual graph I normalize it by the first coefficient of fitting A, the factor in front of the exponents.
Attachment 1: May30-GC650.pdf
May30-GC650.pdf May30-GC650.pdf May30-GC650.pdf May30-GC650.pdf May30-GC650.pdf May30-GC650.pdf
Attachment 2: May30-GC750.pdf
May30-GC750.pdf May30-GC750.pdf May30-GC750.pdf May30-GC750.pdf May30-GC750.pdf May30-GC750.pdf
Attachment 3: June02-GC650.pdf
June02-GC650.pdf June02-GC650.pdf June02-GC650.pdf June02-GC650.pdf June02-GC650.pdf June02-GC650.pdf
Attachment 4: June02-GC750.pdf
June02-GC750.pdf June02-GC750.pdf June02-GC750.pdf June02-GC750.pdf June02-GC750.pdf June02-GC750.pdf
  511   Mon Jun 2 12:20:35 2008 josephbBureaucracyCamerasBeam scan has moved
The beamscan has been moved from the Rana lab back over to the 40m, to be used to calibrate the Prosilica cameras.
  510   Sun Jun 1 19:39:35 2008 tobinConfigurationComputerselog, etc
Phil Ehrens gave me a DVD of the 40m elog, apache, and (Jamie's) SVN archive.
I copied it to nodus:/home/controls/dvd-from-ehrens.  Once we get the elog
running on nodus, we can copy the datafile over again from dziban (so that
we don't lose any elog entries) and switch over.
  509   Sun Jun 1 19:25:10 2008 ranaConfigurationComputersnew monitor on op440m
I installed the new 24" flat screen on op440m. I increased the screen resolution from 1280x1024 to 1900x1200 using
the obscure 'fbconfig' command. You can type Google it if you want.

The old monitor is on the surplus cart. If you are reading this and think you might walk from the 40 over to
Bridge, please wheel the cart full of old computer equipment (on the north side of the control room) over to Larry.

I also copied over all the images on the D40 to a folder on Kirk's computer and deleted the originals.

Dan Busby also visited us last week to help us move the drill press from the Y arm down into the sub basement
of W Bridge.
Attachment 1: Andrey-440.jpg
Attachment 2: Busby08.jpg
  508   Fri May 30 21:30:15 2008 tobinConfigurationComputerssvn on solaris
I installed svn on op440m.  This involved installing the following packages from sunfreeware:

apache-2.2.6-sol9-sparc-local  libiconv-1.11-sol9-sparc-local   subversion-1.4.5-sol9-sparc-local
db-4.2.52.NC-sol9-sparc-local  libxml2-2.6.31-sol9-sparc-local  swig-1.3.29-sol9-sparc-local
expat-2.0.1-sol9-sparc-local   neon-0.25.5-sol9-sparc-local     zlib-1.2.3-sol9-sparc-local
gdbm-1.8.3-sol9-sparc-local    openssl-0.9.8g-sol9-sparc-local

The packages are located in /cvs/cds/caltech/apps/solaris/packages.  The command line to install
a package is "pkgadd -d " followed by the package name.  This can be repeated on nodus to get
svn over there.  (Kind of egregious to require an apache installation for the svn _client_, I 
  507   Fri May 30 12:37:45 2008 robUpdateSUSetmy oplev is back

I relayed the optics for ETMY-oplev as shown in pictures below.
The reflected beam goes directly to the qpd

I turned on the servo. UGFs in PIT and YAW are ~3Hz. I had to flip the sign of the YAW.
  506   Fri May 30 12:03:08 2008 josephb, AndreyConfigurationCamerasHead to head comparison of cameras
Andrey and myself - Joseph B. - have examined the output of the GC650 (CCD) and GC750 (CMOS) prosilica cameras. We did several live motion tests (i.e. rotate the turning mirror, move and rotate the camera, etc) and also used a microscope slide to try to eliminate back reflections and interference.

Both the GC650 and GC750 produce dark lines in the images, some of which look parallel, while others are in much stranger shapes, such as circles and arcs.

Moving the GC750 camera physically, we have the spot moving around, with the dark lines appearing to be fixed to the camera itself, and remain in the same location on the detector. I.e. coming back to the same spot keeps showing a circle. In reasonably well behaved sections, these lines are about 10% dips in power, and could in principle be subtracted out. Its possible that the camera was damaged with too much light incident in the past, although going back to the pmc_trans images that were taken, similar lines are still visible.

Moving the GC650 camera physically seems to change the position of the lines (if one also rotates the turning mirror to get to the same spot on the CCD). It seems as if a slight change in angle has a large effect on these dark bands, which can either be thin, or very large, bordering on the size of the spot size. My guess is (as the vendor suggested) the light is interacting with the electronics behind the surface layer rather than a surface defect producing these lines. Using a microscope slide in between the turning mirror and the GC650, we were able to produce new fringes, but didn't affect the underlying ones.

Placing a microscope slide in between the last turning mirror and the GC750 does not affect the dark lines (although it does seem to add some), nor does turning the final turning mirror, so it seems unlikely to be caused by back reflection in this case.

So it seems the CMOS may be more consistent, although we need to determine if the current line problems are due to exposure to too much light at some point in the past (i.e. I broke it) or they come that way from the factory.

Attached are the results of image-processing of the images from the two our cameras using Andrey's new Matlab script.
Attachment 1: Waveform_Reconstruction_May30-2008.pdf
Waveform_Reconstruction_May30-2008.pdf Waveform_Reconstruction_May30-2008.pdf Waveform_Reconstruction_May30-2008.pdf Waveform_Reconstruction_May30-2008.pdf Waveform_Reconstruction_May30-2008.pdf Waveform_Reconstruction_May30-2008.pdf
  505   Thu May 29 16:49:49 2008 steveBureaucracyPhotosYoichi has arrived
Yoichi had his first 40m meeting. We welcomed him and Tobin, who is visiting, by sugar napoleons that
Bob made.
Attachment 1: yoichi.png
Attachment 2: bobsn.png
  504   Thu May 29 16:32:09 2008 steveUpdateSUSetmy oplev is back
I relayed the optics for ETMY-oplev as shown in pictures below.
The reflected beam goes directly to the qpd
Attachment 1: P1020417.png
Attachment 2: P1020420.png
  503   Thu May 29 15:58:44 2008 JohnSummaryIOOMC realignment
I repeatedly adjusted the yaw of the upper mirror on the input periscope and re aligned the MC. With the PRM aligned I tried to optimise MC transmission and DC refl simultaneously. I subsequently centred the beams on WFS1/2. Attached is a 30 day trend of MC alignment and transmission.
  502   Wed May 28 14:19:47 2008 steveUpdatePSLkaleidoscope of psl
atm 1: scattering psl table optics from the top of the output periscope f4, 60s @MOPA 3 W
atm 2: scattering psl table optics from the top of the output periscope f4, 20s
atm 3: competing GigE cameras on the north end of psl table
atm 4: yellow "soft" washer to be replaced on psl output periscope
atm 5: ETMY-ISCT in disarray
Attachment 1: pslscat.png
Attachment 2: pslscat2.png
Attachment 3: 2GigEs.png
Attachment 4: perwash.png
Attachment 5: etmydisarray.png
  501   Wed May 28 12:51:32 2008 josephbConfigurationComputersTwo more switches mounted
Two more Prosafe 24 port switches have been mounted in the racks, one in 1Y9 and one in 1Y6. (The first one was placed in 1X4).

The one in 1Y9 has been set to an IP address of, while the one in 1Y6 is set to, and these have been labeled as such.
  500   Tue May 27 16:24:54 2008 tobinConfigurationComputer Scripts / Programsndsproxy
The NDS Proxy is a program that accepts NDS (LIGO Network Data Server) connections from the internet and relays them to
our internal frame-builder, so that you can get DAQ and test-point channel data from off-site.

I stopped the ndsproxy that was running on rana and started it on nodus, its new home. This will be
documented in the wiki.

So far I haven't found a mechanism by which the ndsproxy was restarted automatically on rana. Has it just been
restarted by hand?

The ndsproxy stuff lives in target/ndsproxy. Restarting it seems to be just a matter of running "start_ndsproxy" in
that directory.
  499   Sun May 25 22:33:00 2008 ranaUpdateSUSETMY Oplev Work
I found the ETMY table in disarray and put the panels back on and put the ETMY OL laser back on the quad.

The next thing to do is clean up the table (there's a lot of junk on it) and then put in a lens within
6" of the laser to focus the beam on the quad (no metal diving boards and the lens should be either
uncoated (from our Edmunds collection) or a red lens, not 1064).

Then we have to put the beam cover back on between the viewport and the table.
  498   Sun May 25 21:14:14 2008 tobinConfigurationComputersEPICS proxy server
I set up an EPICS gateway server on Nodus so that we can look at 40m MEDM screens from off-site.
The gateway is set up to allow read access to all channels and write access to none of them.

The executable is /cvs/cds/epics/extensions/gateway; it was already installed. A script to start
up the gateway is in target/epics-gateway. For the time being, I haven't set it up to start itself
on boot or anything like that.

To make it work, you have to set the environment variable EPICS_CA_ADDR_LIST to the IP address of
Nodus. For instance, something like this should work:


On Windows you can set up environment variables in the "System" Control Panel. On one of the tabs
there's a button that lets you set up environment variables that will be visible to all programs.

On Andrey's machine I installed the Windows EPICS extensions, i.e. MEDM and its friends. I also
installed the cool Tortoise SVN client which lets you interact with SVN repositories through
the windows explorer shell. (The right-click menu now contains SVN options.) I checked out
the MEDM directory from the 40m SVN onto the desktop. You should be able to just right-click in
that window and choose "SVN Update" to get all the newest screens that have been contributed to
SVN; however, there are currently some problems with the 40m SVN that make that not go smoothly.

At the moment on Andrey's (Windows) machine you can go into the MEDM folder and double-click on
any screen and it will just work, with the exception that not all the screens are installed
due to SVN difficulties.
  497   Sun May 25 20:30:25 2008 ranaSummaryPSLPMC Mode Matching
I checked the PMC mode matching by ramping the gain down to -10 dB (from +20 dB) and
moving the DC offset around until it caught lock on the different HOMs. Then I recorded
the output power (PMCTRANSPD). The DC offset on this EPICS channel was -0.013 V, so I
used its AOFF field to zero this out. Here is a list of the power in the largest modes:
Mode    Power (V)
----    ---------
00        2.7
10        0.2
04        0.04
02        0.02
BE        0.36      **Bull's Eye mode is TEM02 + TEM20. This can be fixed by lens adjustment.

N.B. To make a PNG file with DTT, just make an EPS file -- then use the eps2png perl script.
Attachment 1: pmc.png
  496   Sun May 25 19:33:16 2008 ranaUpdateIOOMC Bad after Re-alignment
The MC pointing was off and the transmitted power was down after John and Andrey brought it back after the bootfest.

I tried getting it back on Friday but was unsuccessful. Today, after the Phoenix Landing, I got it back to someplace
reasonable, but it still seems to be far off. I will check with Rob before we recenter and of the QPDs.

I had to move all of the MC SUS and also align the beam using the IOO periscope. The attached PDF shows some trends
over the last 80 days. You can see that the drop in MC TRANS is about the same as the drop in PMC TRANS.
Attachment 1: e.pdf
Attachment 2: pmc.png
  495   Sun May 25 16:20:27 2008 ranaConfigurationComputersjoinPDF
I have installed joinPDF 2.1 on rosalba. Since its written in Java, I didn't have to tinker with it at all to work on a 64-bit machine. Now Caryn can put all of her plots into 1 file.
  494   Fri May 23 21:21:52 2008 CarynSummaryGeneralfiltering mode cleaner with wiener filter
I tried filtering some saved MC_L data (from Mon May19 4:30pm) with multiple MISO filters of different orders, with various sampling rates, at different times. Plotted the max rms error (where error is signal minus signal-estimate). 2min of data (around Mon May19 4:30pm) were used to calculate each filter. And each filter was applied to data at later times to see how well it performed as time progressed. Plots are attached. There appears to have been a disturbance during the 3rd hour. Rana pointed out perhaps it would be better to use data from the evening rather than during the day.
Attachment 1: error_vs_N_for_different_times_64Hz.pdf
Attachment 2: error_vs_N_for_different_times_128Hz.pdf
Attachment 3: error_vs_N_for_different_times_256Hz.pdf
Attachment 4: error_vs_N_for_different_times_512Hz.pdf
Attachment 5: error_vs_srate_for_different_times_256.pdf
Attachment 6: error_vs_srate_for_different_times_512.pdf
Attachment 7: error_vs_srate_for_different_times_1024.pdf
Attachment 8: error_vs_time_for_different_srates_256.pdf
Attachment 9: error_vs_time_for_different_srates_512.pdf
Attachment 10: error_vs_time_for_different_srates_1024.pdf
  493   Fri May 23 08:24:24 2008 ranaAoGTreasureYoichi Aso has arrived !
Attachment 1: Colossus_back_(800_x_600)-thumb.jpg
  492   Thu May 22 11:25:19 2008 josephbConfigurationComputers 
One of the new Netgear Prosafe 24 port switches was mounted in the 1X4 rack,, roughly in the middle, away from the top and bottom rack mounted electronics. At the moment, its IP has been set to, gateway (which is what I saw as the only listed gateway on linux1 using route -n) and mask

I'm planning to set the next three IP address for the switches as *.251, *.252 and *.253, which don't look to have been used yet.
  491   Thu May 22 11:21:45 2008 steveBureaucracySAFETYearly surf sudent
Caltech under grad Eric Mintun received the 40m safety training.
Now he has to read and sign SOP of laser and ifo.
He'll be working with GigE cameras with Joe
  490   Wed May 21 15:21:33 2008 robUpdateComputer Scripts / Programsautolockers and cron

I added hourly cron jobs to op340m to ensure that

MC autolocker
FSS Slow Servo
PSL watch

are running. I've also edited the wiki procedure to reflect the fact that these no longer need to be restarted by hand.
  489   Tue May 20 18:33:01 2008 Andrey, JohnConfigurationIOOMode Cleaner is locked again

It was noticed by Mr.Adhikari earlier today that the MC became unlocked at about 11AM.

There is no clear understanding what caused the problem.

Trying to restore the modecleaner locking, we noticed with John that the beam was not centered on the wavesensors (WFS1. WFS2 on the screen "C1IOO_LockMC.adl"). We decided to adjust the beam position moving slightly the bias sliders for pitch and yaw degrees of freedom for MC1.
This allowed to make the MC locked.

Old positions for the MC1 sliders: Pitch = 2.9934, Yaw = -0.6168;
New positions --------//---------: Pitch = 3.0604, Yaw = -0.7258.

At the same time, FSS for PSL is still showing the values in the range 0.720 - 0.750 which is lower than the usual values. The indicator for FSS value is yellow when it is below 0.750.
  488   Tue May 20 09:28:42 2008 steveBureaucracySAFETYsafety traning for 40m
Tara Chalernsongsak, new gradstudent for K. Libbrecht was introduced to the basics of the 40m operations.
ELOG V3.1.3-