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  40m Log, Page 246 of 341  Not logged in ELOG logo
ID Date Author Type Categoryup Subject
  4826   Thu Jun 16 00:39:08 2011 KojiUpdatePEMPEM AA Board has been diagnosed and fixed

As seen in the photo, the board has a strange bulge on the board,
and
the color of the internal line around the bulge got darkened.

I don't trust this board any more. We should switch to the alternative one.

Quote:

Steve will re-install the board in the rack in the morning.

 

  4937   Tue Jul 5 08:32:38 2011 steveUpdatePEMbad air quality in the lab

The fireworks of yesterday showing up in the lab. Pasadena out side air 6.6 million  cfm for 0.3 micron particles  and 1.5 million cfm for 0.5 micron size.

Attachment 1: badaq.jpg
badaq.jpg
Attachment 2: july4pem.jpg
july4pem.jpg
  5018   Fri Jul 22 14:22:13 2011 Ishwita, ManuelUpdatePEMSTS-2 seismometer hardware testing

We have two STS-2 seismometer boxes... the blue box & the purple box. Initially we used the blue box for the STS-2 seismometer (named Bacardi by Jenne).

  • Oscilloscope powered on battery was used to test the blue box by observing the velocity output of the three axes (X, Y, Z).  It was found out that the mean value of DC volt of...

X = +10 V

Y = +11 V

Z = -0.1 V

Thus, X and Y axes showed abnormally high DC volt. It was also found out that in AC coupling mode of the oscilloscope... changes were observed in the signal received from Z axis when some seismic wave was generated near the Bacardi by jumping near it. No such changes were observed from signals received from X & Y axes.

  • We removed the blue box and used the purple box for the same Bacardi seismometer & used the oscilloscope powered on battery to test it. It was found out that the mean value of DC volt of...

X = +4.4 V

Y = +4.4 V

Z = +4.4 V

In Ac coupling mode of the oscilloscope... changes were observed in the signals from X, Y, Z axes when someone jumped near Bacardi.

  • The above voltages from the two STS-2 seismometer boxes are unsuitable for the ADC box since it works with voltages ranging from +2 V to -2 V.... meaning it will consider any voltage signal above +2 V as +2 V and any signal below -2 V as -2 V. Hence we need to find out how to use these STS-2seismometer boxes with the ADC box.
  • We also tried measuring the DC volt from the shield and the center of a BNC connector corresponding to Y axis of the purple box (lets call it 'BNC-test') by using BNC-to-banana adaptors and banana wires. Signal from shield of BNC-test was sent to oscilloscope's channel 1 (connected to center of its BNC connector) and signal from center of BNC-test was sent to oscilloscope's channel 2 (connected to center of its BNC connector). On the oscilloscope screen it was observed that both the signals gave the same mean voltage output (-2.2V).
  5033   Mon Jul 25 18:51:38 2011 ManuelUpdatePEMSTS-2 seismometer hardware testing with Jan

[Jan, Manuel, Jenne]

Jenne called Jan to check and figure out why the Streckeisen seismometer (SN #100151) doesn't work, hence we checked the output of the seismometer boxes as we did last friday. (This is the problem of seeing the X and Y channels saturated, when we look at them on a floating 'scope, as in the linked elog entry.)

Jan unplugged and plugged again the orange cable into the seismometer and nothing happened.   Well, what Jan was listening for was "clicks" inside the seismometer indicating that it was receiving power.  We heard these, and moved on to examining the breakout boxes.  Also, we checked that we could hear the "clicks" (one per mass) when we pushed the mass-centering button on the little green companion box.

We weren't sure that the purple box was working properly, so since we had seen the blue box work last time, we changed the purple box with the blue box in rack 1X6.

The Z-channel of the purple box returns a correct signal, that means that all the masses in the seismometer work (because the Z-signal is a linear combination of the three masses U, V, W), the X and Y channel have a DC component of about 10 Volts, Jan said that the recentering of the seismometer masses could need all the night, so we keep the power of the box on. If tomorrow morning the X and Y signal won't  both be zero mean, we will open and check the box.

The power of the box is still on so that the masses can recenter overnight.

Edits by JD

  5045   Wed Jul 27 12:31:47 2011 Manuel, IshwitaSummaryPEMWeekly summary

We kept reading about digital filtering

We tested the seismometer last friday

Jan came and tested again the seismometer last monday

We wrote a simulation of the stacks transfer functions, and of the distance between the mirrors.

 

  5059   Fri Jul 29 12:25:54 2011 Ishwita, ManuelUpdatePEMSTS-2 seismometer box

The 'Bacardi' STS-2 seismometer was tested with the "purple" breakout box and it was found out that all the three axes gave a voltage of 11 V (as shown on the screen of the oscilloscope) before pressing the auto-zero button and after pressing it the voltage shown was 6 V. We tried again the blue box and it was working perfectly after pushing the auto zero button (the auto zero took a few seconds). The power of the purple box is still on, we will wait a few hours, to see if something changes.

  5063   Fri Jul 29 18:43:02 2011 Manuel, IshwitaUpdatePEMplugging seismometers to ADC

[Manuel, Ishwita, Jenne, Jamie]

We changed the C1PEM model and the names of the C1:PEM channels.

We reinstalled the blue breakout box, since the purple one still didn't work.

So, now the AA board channels are connected as follows...

C1 = C1:PEM-SEIS_GUR1_X

C2 = C1:PEM-SEIS_GUR1_Y

C3 = C1:PEM-SEIS_GUR1_Z

C4 = C1:PEM-SEIS_GUR2_X

C5 = C1:PEM-SEIS_GUR2_Y

C6 = C1:PEM-SEIS_GUR2_Z

C7 = C1:PEM-SEIS_STS_1_X

C8 = C1:PEM-SEIS_STS_1_Y

C9 = C1:PEM-SEIS_STS_1_Z

C11 = C1:PEM-SEIS_STS_2_X

C12 = C1:PEM-SEIS_STS_2_Y

C13 = C1:PEM-SEIS_STS_2_Z

C14 = C1:PEM-SEIS_STS_3_X

C15 = C1:PEM-SEIS_STS_3_Y

C16 = C1:PEM-SEIS_STS_3_Z

C17 = C1:PEM-ACC_MC1_X

C18 = C1:PEM-ACC_MC1_Y

C19 = C1:PEM-ACC_MC1_Z

C20 = C1:PEM-ACC_MC2_X

C21 = C1:PEM-ACC_MC2_Y

C22 = C1:PEM-ACC_MC2_Z

Although the channels for all 3 STS-2 seismometers are made but only one is installed. So only Channels C1 to C9 are now in operation...

We checked the data from the plugged channels with the Dataviewer. We could see the peak whenever someone jumped in the lab. Even Kiwamu jumped and saw his signal.

  5134   Sun Aug 7 14:11:53 2011 JenneUpdatePEMParticle counts through the roof

[Jenne, Kiwamu]

While Kiwamu was finalizing the X green alignment, I started to prepare to remove the ETMY door, and begin checking out its OSEMs, etc, so we could start moving it to it's new place, and figure out why it's been wonky for a while.  I ran the particle counter, and we have a factor of ~5 more particles than normal.  Kiwamu and I agreed not to open ETMY.  Since we had briefly opened the IOO and Output Optics chambers to check the X green's position on the PSL table, we immediately shut those doors.  They were probably open for ~15 minutes or so.  (Yes Steve, we should have checked before opening any doors, but at least we remembered to check at all, and the doors were only open for a few minutes rather than for a few hours.)

I attach a 24hrs trend of the particle counts, for reference.  It looks like it's been a little high for a while, but today it's really dirty in the air.

Attachment 1: ParticleCount_High_7Aug2011.png
ParticleCount_High_7Aug2011.png
  5140   Mon Aug 8 14:21:03 2011 steveUpdatePEMParticle counts controlled

Quote:

[Jenne, Kiwamu]

While Kiwamu was finalizing the X green alignment, I started to prepare to remove the ETMY door, and begin checking out its OSEMs, etc, so we could start moving it to it's new place, and figure out why it's been wonky for a while.  I ran the particle counter, and we have a factor of ~5 more particles than normal.  Kiwamu and I agreed not to open ETMY.  Since we had briefly opened the IOO and Output Optics chambers to check the X green's position on the PSL table, we immediately shut those doors.  They were probably open for ~15 minutes or so.  (Yes Steve, we should have checked before opening any doors, but at least we remembered to check at all, and the doors were only open for a few minutes rather than for a few hours.)

I attach a 24hrs trend of the particle counts, for reference.  It looks like it's been a little high for a while, but today it's really dirty in the air.

 The east end particle count is 155K for 0.3 micron and 15K for 0.5 micron  counts/cf min.  In order to minimize diffusion of dirt into the IFO we set up the mobile HEPA with CP Stat 100 tent.

This set up gives us practically ZERO inside the tent

Attachment 1: P1080149.JPG
P1080149.JPG
Attachment 2: P1080150.JPG
P1080150.JPG
  5148   Tue Aug 9 02:27:54 2011 Ishwita , ManuelUpdatePEMPower spectra and Coherence of Guralps and STS2

We did offline wiener filtering on 3rd August (Elog entry) using only Guralps' channels X and Y.

Here we report the Power spectrum of the 3 seismometers (Guralp1, Guralp2, STS1) during that time.

and also the coherence between the data from different channels of the 3 seismometers.

We see that the STS is less correlated with the two Guralps. We think it is due to the wrong alignment of the STS with the interferometer's axes.

We are going to align the STS and move the seismometers closer to the stacks of the X arm.

 Pw_gurs_correct.png

 

 


 Pw_gur1_sts1_correct.png


 

 


 

 Coher_gur1_gur2_BW0.01.png

 

 



Coher_gur1_sts1_BW0.01.png

 

 



Coher_sts1_gur2_BW0.01.png

  5168   Wed Aug 10 12:28:22 2011 Ishwita , ManuelUpdatePEMAA board gain

We used a function generator, an oscilloscope and the Data Viewer to check the gain of the new AA board (used for the seismometers). Putting a sine wave of 0.3V (using a function generator) to the AA board, we could see about 500 counts in the Data Viewer. The calibration of the ADC is 214 counts/volt, so the AA board gives to the ADC an output of 0.03V. This proves that the AA board has a gain of 0.1. Guralp1 and STS1 (Bacardi), both have a gain of 10 now, that balance the AAboard gain of 0.1. If we consider the gain of AA board in our calibrated power spectrum plot of seismic signals from Guralp1 and STS1 (Bacardi), we get the following plot:

pw_gur1_sts1_aug10.png

  5170   Wed Aug 10 12:33:34 2011 Manuel, IshwitaSummaryPEMWeekly summary

We got the results of the wiener filtering simulations (Elog Entry)

We got the power spectra and coherence of the seismic noise measurements from GURALPs and STS seismometers (Elog Entry)

We tried to whiten the target and the input signal for the computation of the wiener filter for the real data, but the results are unsatisfactory. We should not care about high frequencies in wiener filter computation so we will just filter them off in the filter output with a low pass filter.

We just found the right gain for the system seismometer-AAboard-ADC (Elog Entry)

  5171   Wed Aug 10 13:52:23 2011 Manuel , IshwitaUpdatePEMMoving Seismometers

We turned off the power of the seismometers and moved the Guralp1 close to the STS. Both are now situated below the center of the mode cleaner vacuum tube.

We oriented the X axis of the STS & Guralp1 along the X axis of the interferometer. Then we turned on the power again, but the STS channels don't give any signal. We think this is, because we didn't push the auto zero button.

  5172   Wed Aug 10 14:27:39 2011 Ishwita , ManuelUpdatePEMCalibration of Guralp and STS2

ADC: 216counts = 4V Hence, calibration of ADC is 214counts/V.

Gain of the AA board, g1 = 0.1


GURALP

Sensitivity = 800 V/ms-1

214 counts/V x 800  V/ms-1 = 13107200 counts/ms-1 -----> 7.6294e-08 ms-1/count

Gain, g2 = 10

Calibration = 7.6294e-08 ms-1/count x g1 x g2 = 7.6294e-08 ms-1/count


 STS

Sensitivity = 1500 V/ms-1

214 counts/V x 1500  V/ms-1 = 24576000 counts/ms-1 -----> 4.069e-08 ms-1/count

Gain of the STS electronic breakout box, g3 = 10

Calibration = 4.069e-08 ms-1/count x g1 x g3 = 4.069e-08 ms-1/count

  5174   Wed Aug 10 14:35:39 2011 ranaUpdatePEMCalibration of Guralp and STS2

I'm pretty sure that don't have any ADC's with this gain. It should be +/- 10V for 16 bits. 

  5175   Wed Aug 10 15:17:39 2011 Ishwita, ManuelUpdatePEMCalibration of Guralp and STS2

Quote:

I'm pretty sure that don't have any ADC's with this gain. It should be +/- 10V for 16 bits. 

Jenne told us that the ADC was +/- 2V for 16 bits so our calibration is wrong. Since, the ADC is +/- 10V for 16 bits we need to change our calibration and now we can also use the purple STS breakout box.

  5185   Thu Aug 11 09:39:25 2011 Ishwita, ManuelUpdatePEMCalibration of Guralp and STS2

Quote:

Quote:

I'm pretty sure that don't have any ADC's with this gain. It should be +/- 10V for 16 bits. 

Jenne told us that the ADC was +/- 2V for 16 bits so our calibration is wrong. Since, the ADC is +/- 10V for 16 bits we need to change our calibration and now we can also use the purple STS breakout box.

 New calibration for Guralp:

ADC: 216counts = 20V Hence, calibration of ADC is (215x0.1) counts/V.


GURALP

Sensitivity = 800 V/ms-1

(215 x 0.1) counts/V x 800  V/ms-1 = 2621440 counts/ms-1 ----->  3.8147e-07 ms-1/count

Calibration = 3.8147e-07 ms-1/count


Using the above calibration we obtain the following plot:

pw_gurs_aug11.png

When we compare this plot with the old plot (see here) we see that in our calibration, we have got a factor of 10 less than the old plot. We do not know the gain of the Guralp. If we assume this missing 10 factor to be the gain of Guralp then we can get the same calibration as the old plot. But is it correct to do so?

  5186   Thu Aug 11 10:56:08 2011 Ishwita, ManuelUpdatePEMMoving Seismometers

Quote:

We turned off the power of the seismometers and moved the Guralp1 close to the STS. Both are now situated below the center of the mode cleaner vacuum tube.

We oriented the X axis of the STS & Guralp1 along the X axis of the interferometer. Then we turned on the power again, but the STS channels don't give any signal. We think this is, because we didn't push the auto zero button.

 After pressing the auto-zero button (a lot of times) of the STS breakout box & aligning the bubble in the STS, we could finally get data from STS (Bacardi). So, now STS2 (Bacardi - Serial NR. 100151) is working!

  5187   Thu Aug 11 11:50:56 2011 Manuel , IshwitaUpdatePEMCalibration of Guralp and STS2

 

 We just checked with a function generator the calibration of the ADC. We set a square wave with amplitude 1V. We measured the voltage with the oscilloscope and we found on the data viewer that one volt is 3208 counts. That's what we expected (+/- 10V for 16bits) but now we are more sure.

 

  5190   Thu Aug 11 13:41:36 2011 Ishwita, ManuelUpdatePEMCoherence of Guralp1 and STS2(Bacardi, Serial NR 100151)

Following is the coherence plot obtained when Guralp1 and STS2(Bacardi, Serial NR 100151) are placed very close to each other (but they aren't touching each other):

coher_gur1_sts1_near.png

The seismometers were placed as shown in the picture below:

coherence_pic.JPG

They are placed below the center of the mode cleaner vacuum tube.

  5196   Thu Aug 11 16:15:59 2011 Ishwita, ManuelUpdatePEMCalibration of Guralp and STS2

 

Finally, we have found the correct calibration of Guralp and STS2 seismometers.

ADC: 216counts = 20V Hence, calibration of ADC is 3.2768e+03 counts/V.


 

GURALP

Sensitivity of seismometer = 800 V/ms-1

Gain of the guralp breakout box (reference elog entry) = 20

Calibration = 3.2768e+03 counts/V x 800  V/ms-1 x 20 = 52428800 counts/ms-1 -----> 1.9073e-08 ms-1/count


STS

Sensitivity = 1500 V/ms-1

Gain of the STS electronic breakout box = 10

Calibration = 3.2768e+03 counts/V x 1500  V/ms-1 x 10 = 49152000 counts/ms-1 -----> 2.0345e-08 ms-1/count

 

  5197   Thu Aug 11 16:21:16 2011 Ishwita , ManuelUpdatePEMPower spectra and Coherence of Guralps and STS2

 

 Following is the power spectrum plot (with corrected calibration [see here]) of seismometers Guralp1 and STS2(Bacardi, Serial NR 100151):

Pw_gur1_sts1_correct.png

 

 The seismometers are placed approximately below the center of the mode cleaner vacuum tube.

  5200   Thu Aug 11 19:14:22 2011 Ishwita , ManuelUpdatePEMSeismometer STS2(Bacardi, Serial NR 100151) moved near ETMX

We moved the STS2(Bacardi, Serial NR 100151) to his new location and laid his cable from rack 1X7 to ETMX. The seismometer was below the mode cleaner vacuum tube before.

Now, (since 6:05pm PDT) its placed near the ETMX.

cable_to_etmx.pngsts2_etmx.png

 

  5201   Fri Aug 12 00:18:30 2011 Ishwita, ManuelUpdatePEMCoherence of Guralp1 and STS2(Bacardi, Serial NR 100151)

 

 We moved the seismometer STS2(Bacardi, Serial NR 100151) as we told in this Elog Entry, so the distance between Guralp1 and STS2 is 31.1m. Following is the coherence plot for this case:

coher_gur1_sts1_31m.png

then we also moved the Guralp1 under the BS and plugged it with the Guralp2 cable (at 7:35pm PDT), so now the distance between the two seismometers is 38.5m. Following is the coherence plot for this case:

coher_gur1_sts1_38.png

  5213   Fri Aug 12 17:05:22 2011 Manuel, IshwitaConfigurationPEMSTS2 Cable configuration

The WWF_M connector is the end of the STS2 seismometer orange cable and the S1 connector is the end of the gray 26-pin-cable

01050901.PDF

  5366   Thu Sep 8 13:20:07 2011 steveUpdatePEMvac envelope at atm for 36 days

We tried not to open chambers above 10,000 particles of 0.5 micron cf/min

New items going in:                       2 rasor beam traps, 5 badly oxidized old silver plated  setscrew with spring loaded tips......to be replaced in the future, viton tips for eq screws....some are lose, gold plated allen wrench installed at ITMX bottom, reglued magnet on ITMX

Bad hardware things found:          nylon ball "locking elements" on OSEM locking set screws with screwdriver  slot, lose  1064 nm filter on OSEM pd

Attachment 1: vent70.jpg
vent70.jpg
  5407   Wed Sep 14 15:05:52 2011 steveUpdatePEMair cond maintenance

Jeff has changed our AC filters inside the lab this morning. Now he is checking on the main filters at CES.  He will finish the roof units tomorrow.

Met One #1 counter is on the top of IOO chamber.  It is measuring 1 and 0.5 micron size particles.  One year of lab condition plot below.

 

Attachment 1: ac1y.jpg
ac1y.jpg
  5567   Wed Sep 28 18:39:50 2011 MirkoUpdatePEMBLRM seismic channels in c1pem

[Mirko,Jenne]

Created 5-band BLRMS for seismometer data (Gur1, Gur2 and STS1 each in x,y,z respectively) and accelerometer 1 through 6.

Bands are:
0.1Hz-0.3Hz
0.3Hz-1Hz
1Hz-3Hz
3Hz-10Hz
10Hz-30Hz
each with a fitting 4th order butterworth bandpass.

Data is recorded at 256Hz as e.g. C1:PEM-ACC1_RMS_RMS_0p3_1_OUT_DQ. For the 75 channels we have that corresponds to the data rate of just 1.2 16kHz channels.

c1pem execution time increased fom 6-7us to 15-16us out of 480us available.

  5700   Wed Oct 19 15:48:20 2011 MirkoUpdatePEMMoved the STS1 from x-arm end to vortex

[Jenne, Mirko]

We moved our one STS1 from the x-arm end to the vortex. We record the data as STS1 in c1pem @ 256Hz. x is still north-south.

JD:  This is actually an STS-2.  We just call it C1:PEM-SEIS_STS1.... to differentiate the 3 STSs that we have from one another (assuming we plug in the other two).

19102011061.jpg

  5986   Wed Nov 23 02:34:28 2011 MirkoUpdatePEMSeismic spectrum & Striptool

The Striptool for the BLRMS seismic channels is running now. Channels are ( still ) recorded as slow EPICS channels.

A big peak in the 0.1 - 0.3Hz seismic region in both GUR1 and STS1 irritated us for a while. I added an extra LP filter @ 0.05Hz to the RMS_LP modules.

SeismicSpectrum.pdf

 

  6058   Thu Dec 1 11:25:10 2011 steveUpdatePEM40m infrastructure holds up well in strong wind condition

 Santa Anna wind speed was locked around 60 kmph last night on campus. The strongest in 30 years.  The lab hold up well. We did not lose  AC power either.

Threes and windows were blown out and  over on campus.

We have 4 sliding glass windows without "heavy-laser proved" inside protection.

We should plan to upgrade ALL  sliding glass windows with metal protection from the inside.The strongest in 30 years.

Attachment 1: santaannawind.png
santaannawind.png
Attachment 2: wind.png
wind.png
  6139   Tue Dec 20 15:49:21 2011 steveUpdatePEMoptical table top

3/4 " thick colored acrylic material will be used in this air tight design. Surgical tubing for o-ring. We may have to put an o-ring into the bottom to have it really air tight.

Feedtrouhs: www.roxtec.com

The top drawing is not ready. It will have handle and industrial grade L-handle lock pin to hold cover down. There will be 2  one inch od post in the midle of the table to hold the cover and lock  the ball pin.

I'm waiting for your inputs, so I can send this preliminary design out for quote.

 

Attachment 1: 05150901.PDF
05150901.PDF
  6190   Thu Jan 12 10:11:59 2012 steveUpdatePEMoptical table top with 1" wall

Quote:

3/4 " thick colored acrylic material will be used in this air tight design. Surgical tubing for o-ring. We may have to put an o-ring into the bottom to have it really air tight.

Feedtrouhs: www.roxtec.com

The top drawing is not ready. It will have handle and industrial grade L-handle lock pin to hold cover down. There will be 2  one inch od post in the midle of the table to hold the cover and lock  the ball pin.

I'm waiting for your inputs, so I can send this preliminary design out for quote.

 

 The present plan to go with clear cast acrylic plexiglass 1" thick side wall  and  two  clear  1/2 thick top cover.

The inside would be lined with light braun YAG safety window sheets 0.14"  VLT ~25%  OD 4 @ 532nm & OD 5 @ 1064nm

 

Attachment 1: 101122012atc.PDF
101122012atc.PDF
  6191   Thu Jan 12 11:08:23 2012 Leo SingerUpdatePEMFunky spectrum from STS-2

I am trying to stitch together spectra from seismometers and accelerometers to produce a ground motion spectrum from Hz to 100's of Hz.  I was able to retrieve data from two seismometers, GUR1 and STS_1, but not from any of the accelerometers.  The GUR1 spectrum is qualitatively similar to other plots that I have seen, but the STS_1 spectrum looks strange: the X axis spectrum is falling off as ~1/f, but the Y and Z spectra are pretty flat.  All three axes have a few lines that they may share in common and that they may share with GUR1.

See attached plot.

Attachment 1: spectrum.jpg
spectrum.jpg
  6210   Wed Jan 18 12:38:44 2012 steveUpdatePEMAcrylic plexiglass transmittance

Acrylite-Gp.pptx

Transparent- clear plexyglass from tree different sources were measured in 1064 and 532 nm light.

Samples: a, clear Acrylic-GP 0F00  from Ridout Plastics in thickness 0.7" ,  made by  Evonic Ind

                   b, clear cast acrylic from Mc Master Carr in thickness 0.94" , likely  made by Reynolds-Cast

                   c, clear cell cast  plexyglass from Delvie's Plastics - Utah in thickness  0.93" , maker not known

PMC reflected beam was used at 92 mW and 6 mm diameter at incident angle 0-25 degrees.

All tree samples agreed on Transmittance of ~90%, Reflectivity ~3-4% and calculated Adsorption ~6-7%

 

Transparent Colored Acrylic orange-amber #2422   from www.eplastics.com in 0.12" thickness gave  T 96%,  R 1% and  Ab-calc ~3% in the beam of 92 mW 1064  nm at 6 mm diameter.

 

Transparent , colored   Light Red #26 thin film filter   policarbonate-polyester   0.002" thick   from Roscolux measured T 81% of 115 mW 1064 nm

 

Now I changed power meter FieldMate to Ophir and the light source to laser pointer 2.2 mW  ~532 nm  with 1-2 mm beam diameter.

Orange - amber #2422  sample, 0.12" thick,  T 1% ,  R 4%  and  Ab-calculated ~95%, estimated visibility  ~50% It does cut out the green at this low power level.

 Light red #26  sample  T 0.5%  at 2.5 mW of 532 nm . The transparent green is not visible.  The softening point of this sandwiched polycarbonate-polyecter filter is 160C. Estimated VLT of this film ~40%

 

SUMMERY:

Clear and colored acrylics'  @ 1064 nm  transmittance 90% or higher  regardless of thickness. Softenig point 115 degrees C

Colored acrylic and colored policarbonate film are adsorbing the low power green and they  transmit the 1064nm beam.

Options to consider: a, acrylic laser safety shield liner of  0.125" thick inside of 1" thick clear acrylic  box, OD +5 @1064 and OD +4 @ 532nm,  amber color VLT 27%,  150$/sqft

                                      b, thin metal liner for 1" wall acrylic box, VLT 0%

                                     

 

Attachment 2: roscogel_red#26_film.pdf
roscogel_red#26_film.pdf
  6237   Mon Jan 30 16:18:51 2012 steveUpdatePEMRoscolux colored film transmittance at 1064 nm

 

 Roscolux filter films  #74 night blue,  0.003" thick  and  #26 light red, 0.002" thick  were measured in the beam path of  ~6 mm diameter,  1W 1064 nm .

T 90%  + - 5% at 0-30 degrees of  incident angles and R ~10 % 

These sandwitched thin films of policarbonate-polyester filters are not available in thicker forms. Rosco is recommending them to be cooled by air if used in high power beam.

These filters did not get warm at all in 1W, so absorption must be very small.

  6245   Fri Feb 3 14:47:51 2012 steveUpdatePEMlaser interlock drawing

 Rough draft of      updated interlock drawing by Ben is here.

 

  6247   Fri Feb 3 16:13:49 2012 steveUpdatePEMLED lights for chamber illumination

Cold LED lights replaced hot halogen ones. Flat LED MYAL 6S,  model #112560002  24VAC

This is a LATE ENTRY.  They were purchased  in Jan 2010 and installed 6 of them around May 2010

Attachment 1: P1080526.JPG
P1080526.JPG
  6271   Fri Feb 10 15:47:38 2012 ranaUpdatePEMseismic noise back to normal

 

 Kiwamu and Steve maybe don't know about how to trend seismic noise. If you just take the mean of the time series, you don't prove that the seismic noise got any higher. The STS has a nominally zero DC output, so the long period level shifts that you see tell you just that there was a DC offset.

This is NOT an increase in seismic noise. To see a seismic trend you should plot the trend of the BLRMS channels that we made especially for this purpose.

  6272   Fri Feb 10 15:52:35 2012 JenneUpdatePEMseismic BLRMS loud too

Quote:

 

 Kiwamu and Steve maybe don't know about how to trend seismic noise. If you just take the mean of the time series, you don't prove that the seismic noise got any higher. The STS has a nominally zero DC output, so the long period level shifts that you see tell you just that there was a DC offset.

This is NOT an increase in seismic noise. To see a seismic trend you should plot the trend of the BLRMS channels that we made especially for this purpose.

 So, none of our PEM BLRMS channels are recorded as of right now.  All we have for long-term record is the StripTool on the wall.  The 0.1-0.3Hz and 0.3-1 Hz traces both show these weirdo things, but the 1Hz and up BLRMS don't have any unusual noise.

  6273   Fri Feb 10 15:54:27 2012 steveUpdatePEMAC turned back ON

The air cond was off for 2 hrs.  I just switched it back on at 15:51

  6275   Fri Feb 10 23:58:30 2012 ranaUpdatePEMseismic BLRMS loud too

Quote:

 

 So, none of our PEM BLRMS channels are recorded as of right now.  All we have for long-term record is the StripTool on the wall.  The 0.1-0.3Hz and 0.3-1 Hz traces both show these weirdo things, but the 1Hz and up BLRMS don't have any unusual noise.

 Seems like a problem to solve on Monday so that we don't end up without trends like this again.

  6276   Mon Feb 13 11:30:51 2012 JenneUpdatePEMseismic BLRMS loud too

Quote:

Quote:

 

 So, none of our PEM BLRMS channels are recorded as of right now.  All we have for long-term record is the StripTool on the wall.  The 0.1-0.3Hz and 0.3-1 Hz traces both show these weirdo things, but the 1Hz and up BLRMS don't have any unusual noise.

 Seems like a problem to solve on Monday so that we don't end up without trends like this again.

 Tragically, this is more tricksy than I would have thought. The channels we need are "cdsEpicsOutput"s in the model.  They don't show up in Dataviewer (fast or slow channels) or the regular fast channel .ini file.  Jamie and I don't remember where these channels live and how to get them saved to frames.  I'm on top of it though.

I did notice however, that the striptool for seismic trends is showing the wrong channels for 3-10 and 10-30 Hz.  The other 3 channels are correctly the output after the sqrt is taken, but those two (orange and red on striptool) are before the sqrt, but after the bandpass and low pass.  I'll fix that now...

  6277   Mon Feb 13 12:02:17 2012 KojiUpdatePEMseismic BLRMS loud too

I reported the procedure to add slow channels to the FB. I guess you already have done Step.1

http://nodus.ligo.caltech.edu:8080/40m/5991

Quote:

 Tragically, this is more tricksy than I would have thought. The channels we need are "cdsEpicsOutput"s in the model.  They don't show up in Dataviewer (fast or slow channels) or the regular fast channel .ini file.  Jamie and I don't remember where these channels live and how to get them saved to frames.  I'm on top of it though.

 

  6328   Mon Feb 27 21:26:22 2012 DenUpdatePEMseis box

I did liso simulation of the circuit in the seis box. I think that AD620 (first amplifier in the circuit) noise might be much less with the signal from guralps from 0.01 Hz. Here is the TF of AD620 output / circuit input.

ad620.pdf

The noise spectrum is at this node is

noise.pdf

The psd of the seismic noise below 1 Hz ~ 1u m/s => circuit input signal is ~1mv.

The TF of the whole circuit is

whole.pdf

This result differs from the graph on the circuit sheet, but may be it was done before the resistor parameteres changed. Back of the envelop calculations also show that it is not possible to acheive DC gain 200 while 50-800 Hz gain = 5000. I'll check with the spectrum analyzer.

AD620 might be a weak point in the simulation since this is not a "classical" operational amplifier, it contains a resistor that adjusts the gain. During the liso simulation I assumed that we have an ordinary opamp (with noise, gain and gbw parameters taken from the real ad620 datasheet) with a resistor parallel to the opamp = 50k and a resistor before the inverted input that corrsponds to R2. In this case the gain of the simulated opamp is the same as of the real one given by the formula 1 + 49.9k / R2, though noise parameters may change. This should be also checked with the spectrum analyzer.

  6338   Wed Feb 29 01:02:06 2012 DenUpdatePEMseis box measured

I've measured the input signal to the seismic box from seismometer Guralp 1. The spectrum of the signal in the "input +" (TP 1) is

input.png

 

The spectrum below 1 Hz is ~250 uV/sqrt(Hz). As the input is differential, then the input voltage is 0.5 mV/sqrt(Hz). The spectrum of the "output +" signal (TP 2) is

output.png

 

So the gain at ~ 1Hz is ~20. I've measured the transfer function between the "input +" and "output +" (TP1 and TP2) for all 9 circuits

tf.png

The channels 1-6 are of new modification and have gain ~20 at the frequencies 0.2 - 100 Hz. Below 0.2 Hz the gain is reduced. 100 Hz - cut off frequency of the low-pass filters. Meanwhile channels 7-9 (old configuration) have much more gain and 10_50 Hz filters work here.

The coherence between  "input +" and "output +" (TP1 and TP2) for 9 circuits is

 

coherence.png

We can see that channel VERT 3 is very bad. For others coherence is lost below 0.2 Hz. The spectrum analyzer noise measured is ~1000 times less then the signal at these frequencies. I'll pay more attention to this loss of coherence at low frequencies. Something is noisy.

  6343   Thu Mar 1 00:05:23 2012 DenUpdatePEMseis box noise

I've moved GUR1 seismometer from MC2 to the working tables in order not to disturb the MC while working with the seismometer box. The new place for the GUR1 for a few days is near the printer, cables and blue boxes. I've cleaned all mess and wires from the floor, so that seismometer now looks like that

DSC_3959.JPG

I've connected 2 inputs of the N/S 1 circuit of the seismometer box with a 50 Ohm resistor and measured the noise at the output. The comparison with the seismic signal is

noise.png

The noise increased at 0.5 Hz and is pretty big. This might explain the loose of coherence at low frequencies.

  6345   Thu Mar 1 21:48:34 2012 DenUpdatePEMseis box noise

Quote:

The noise increased at 0.5 Hz and is pretty big. This might explain the loose of coherence at low frequencies.

 This is because spectrum analyzer did not plot the real noise spectrum at the first few points at low frequencies. I've remeasured the noise at 1mHz - 3Hz at "output -" (TP9) and compared it to the seismometer signal

noise2.png

The noise seems to be much less then the signal. I've measured the noise several times and once I got a huge amount of noise

noise.png

 

I made another measurement in some time and got the low noise again. A circuit might have a bad contact somewhere.

The plan is to change AD620 adjustable resistor (R2) from 5.49kOhm to 500Ohm to increase the gain from 20 up to 200.

  6346   Fri Mar 2 11:05:28 2012 DenUpdatePEMseis box gain

I've replaced R2 resistor that adjusts the gain of the AD620 amplifier. Previous value 5491Ohm, new value 464Ohm, so the gain should increase up to ~200-250. Only at the N/S 1 circuit!

LISO simulation of the circuit transfer function and noise are

tf_new.pdf

noise_new.pdf

LISO predicts gain ~45-46 dB = 200 and noise at the level of 10uV at 1Hz. The transfer function and noise measured are

tf_analyzer.png

 noise_analyzer.png

The noise measured is 5 times higher then predicted by LISO. Though I described AD620 as an ordinary amplifier with 49.9kOhm resistor connecting output and inverted input. I specified the noise spectrum 10 nV and 1/f corner frequency 30 Hz. In the AD620 datasheet noise spectrum is 10 - 100 nV depending on the gain. However, the gain is 200 and noise spectrum should be 10 nV. May be in reality it is not the case. It also possible that the noise model used by LISO is not valid for AD620 as it is not an ordinary operational amplifier.

  6349   Fri Mar 2 18:55:06 2012 DenUpdatePEMseis box

I've put the seismometer box back to the 1x1, Guralp is back under MC2. When the seismometer is not plugged in, the noise is

dv_noise.png

Now, I'm going to collect some data from GUR 1 and MC_F and see if the problem with adaptive filter (increasing errror while decreasing mu) will be gone.

 

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