 Tue Mar 20 16:56:01 2018, Kira, Update, PEM, test setup 
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The MOSFET was getting pretty hot, so I switched it out to a larger heat sink and it's fine now. I then used a function generator in place of the
DAC to provide ~3.5V. I got the current in the circuit to 1.7A, which is as expected, since we have 24V input, the heater resistance is 12.5ohm and the
resistor we are using is 1ohm, so 24V/(12.5+1)ohm = 1.7A. The temperature inside the can rose about 5 degrees in half an hour. The only issue now |
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Tue Mar 20 19:48:10 2018, gautam, Update, PEM, test setup
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according to the temp sensor readout, which was ~-3.35V which corresponds to ~335K, the temperature of the can is now 60
deg C. This is a bit warm for my liking so i'm turning the heater current down to 0 now by writing 0 to C1:PEM-SEIS_EX_TEMP_CTRL |
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Fri Mar 23 12:00:20 2018, rana, Update, PEM, test setup
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we don't ever want to use our 16 kHz real time system for such low frequency action; its main purpose is for real-time controls, whereas we are OK
with multiple seconds of delay in a thermal loop. The Python PID script is sufficient and highly reliable (after years of testing). |
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Fri Mar 23 12:45:08 2018, Kira, Update, PEM, test setup
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I fit the data that we got from the test. The time constant for the cooling came out to be about 4.5 hours. The error is quite large and we should add
a low pass filter to the temperature sensor eventually in order to minimize the noise of the measurements. |
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Thu May 17 15:38:19 2018, Kira, Update, PEM, test setup with seismometer
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I've moved my setup to the actual seismometer. I attached the temperature sensor to the seismometer (attachment 1) with duct tape, though this is
temporary. I will be monitoring the temperature fluctuations of the seismometer for a whole day then take the can off and repeat the test. The can isn't
clamped down so the insulation isn't perfect, so I'd expect to see some noticeable fluctuations even with the can on. I've also labeled the |
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Fri May 18 14:33:34 2018, Kira, Update, PEM, test setup with seismometer
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Here is the result of my test. I think I'll leave the can on over the weekend because there's a long period of time where the seismometer heated
up by 0.8 degrees so I can't fully see the fluctuations over a full 24 hour period. |
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Mon May 21 10:15:35 2018, gautam, Update, PEM, test setup with seismometer
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I guess it's fine for now while we are still finalizing the setup at EX, but we should eventually line up the seismometer axes with the IFO axes.
Is there a photo of the orientation of the seismometer pre heater can tests? If not, probably good to make some sort of markings on the granite slab /
seismometer to allow easy lining up of these axes... |
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Mon May 21 14:17:28 2018, Kira, Update, PEM, test setup with seismometer
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I have attached the graph for the seismometer temperature fluctuations over 3 days. As we can see, there is a noticeable fluctuation in daily temperature
as well as a difference between days in the maximum and minimum temperatures. I will repeat this test but take the can off to see if there's any difference
between having the can on or off. |
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Tue May 22 14:49:03 2018, Kira, Update, PEM, test setup with seismometer
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It appears that one of the wires was disconnected overnight or this morning so I wasn't able to gather data over a full 24 hour period. Perhaps someone
accidentally kicked it. I placed some cones in that area so hopefully the wires won't be in the way as much and I can get the data tomorrow. From the
data I do have it seems that the seismometer is at a colder temperature when the can is not on, though it is difficult to see by how many degrees the temperature |
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Wed May 23 14:50:33 2018, Kira, Update, PEM, test setup with seismometer
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This time the test went without issue. The first attachment is the data for the past 24 hours and the second attachment is the full data over 6 days.
The average temperature fluctuations (from highest point to lowest point) for the can on was 0.43 C and for the can off it came out to 0.55 C. In addition
the seismometer with the can off is about 1 C cooler than with the can on. I'd like to leave the can off until the end of the week so we can get a |
 Fri Sep 24 00:56:35 2010, koji, tara, Update, Electronics, testing TTFSS
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We found that a transistor was broken from yesterday spark too. We partially fixed TTFSS, and it should be enough
for testing purpose.
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Fri Sep 24 23:47:10 2010, koji, tara, Update, Electronics, testing TTFSS
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Q3, a PZT2222A transistor, on D0901846 is replaced by a GE-82. However, the board is still not fully function.
Since Q3, PZT2222A, was broken, I went to Wilson house and got some SP3904's for replacement. But somehow, |
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Sat Sep 25 19:01:13 2010, Koji, Update, Electronics, testing TTFSS
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How much current do you need for each voltages?
GE-82 was the only PNP transister I could find in the lab. It's too old but we just like to confirm any other components are still functioning.
Similarly, we can confirm the functionality of the other components by skipping those current boost transisters, |
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Tue Aug 30 11:42:29 2011, jamie, Update, CDS, testpoint.par file found to be completely empty
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The testpoint.par file, located at /opt/rtcds/caltech/c1/target/gds/param/testpoint.par, which tells GDS processes where to find the various awgtpman
processes, was completely empty. The file was there but was just 0 bytes. Apparently the awgtpman processes themselves also consult this file
when starting, which means that none of the awgtpman processes would start. |
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Thu Jun 21 09:01:18 2012, steve, Update, STACIS, the resurrection of STACIS -surf
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There is a small wood cabinet under the south end flow bench, labeled STACIS.
Unit is complete with extension cards and cables. |
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Tue Oct 12 15:51:18 2010, yuta, Bureaucracy, SAFETY, the 40m squad received safety training from Peter
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Yuta, Joonho, and Suresh received the Basic Laser Safety Training from Peter King today.
Now, we got homework. |
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Fri Jul 11 09:29:02 2008, steve, Update, PSL, the PMC still hangs up
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Morning alarms:
PMC high voltage is railing, it's auto locker is frosen
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Mon Sep 13 21:52:53 2010, kiwamu, Update, Green Locking, the X end laser is ON
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I turned ON the laser at the X end station, which had been OFF
for several weeks because of the crane business.
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Tue Aug 30 09:51:37 2016, Steve, Update, SUS, the chamber HEPA tents are back
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How to minimize particles entering the vacuum envelope.
Just the way it was in August 2011 vent and before. |
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Wed Aug 31 23:01:02 2016, gautam, Update, SUS, the chamber HEPA tents are back
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Some more numbers we found while working in/around the chamber today:
Particle counts
Area
0.3 |
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Thu Dec 23 08:54:32 2010, Suresh, Update, elog, the delhi univ syndrome
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Sorry folks! I couldnt get to the elog and didnt know that the elog was crashing every time I tried to access it.
But have found other means to access it and the elog is safe for now! |
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Mon Aug 4 12:12:20 2008, steve, Configuration, VAC, the ifo is at atm
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The 40m vac envelope was vented this morning.
P1 is at 760 Torr |
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Mon Aug 22 16:33:32 2016, Steve, Update, PEM, the lab temp is up
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| The IFO room temp is up a bit and it is coming down. The out side temp is not really high. |
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Mon Aug 22 18:35:16 2016, Praful, Update, PEM, the lab temp is up
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The temperature is decreasing slowly but is still above 24 C.
temp_plot.png |
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Fri Oct 7 15:36:03 2016, Steve, Update, PEM, the lab temp is up
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The IFO room temp is up
Quote:
The IFO room temp is |
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Fri Nov 2 08:59:30 2007, steve, Bureaucracy, SAFETY, the laser is ON
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| The psl laser is back on ! |
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Thu Feb 21 09:56:26 2008, steve, Update, PSL, the laser is back
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The laser and the psl recovered.
The water chiller temp is 19.98C and head temp 18.4C
Power 3.2W
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Fri May 29 18:57:09 2009, steve, Update, PSL, the laser is back
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Steve, Rob and Alberto
Starting capacitor 216 miroFarad was installed on the compressor. Water lines were connected to the MOPA as corrected, so the flow meter readings |
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Wed Feb 20 16:24:37 2008, steve, Update, PSL, the laser is recovering slowly
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Head temp is still 20.5C and decreasing slowly.
Power output 2.9W
NPRO power 22 mW is increasing as head is cooling down |
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Thu Jan 24 11:52:56 2008, steve, Update, PEM, the mud is cleaned up & MOPA shutter is opened
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Safety glasses are required again!
I have just opened the mopa shutter.
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Tue Nov 23 10:48:31 2010, Koji, Update, IOO, the plan of the day
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[Kiwamu/Koji]
- The tanks are open
Plan |
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Mon Sep 8 10:57:49 2008, steve, Update, IOO, the psl and mc are back to normal
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The alarm handler is silent this morning.
This is almost unbelievably pleasant after two mount of harassment.
The MC did not lose lock for three days.
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Wed Jan 10 09:49:28 2018, Steve, Update, PEM, the rat is back
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Five mechcanical traps set inside of boxes. Red-white warning tape on top of each.
Quote:
Last jump at rack Y2. |
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Mon Oct 29 09:16:31 2007, steve, Routine, VAC, the rga is back
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We had no filament current since last power glitch of Oct. 8, 2007
First I thought that the filament was lost, but it was only bad contact.
The rga head pins were oxidized. Rga was turned back on last Friday.
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Thu May 28 18:41:26 2009, steve, Update, PSL, the saga of the chiller is ending
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I drained the water and removed side covers from the Neslab RTE 140 refrigerated water cooler unit this morning. The hoses to the laser were disconnected.
This abled you to see the little window of refregerant R404A was free of bubles, meaning: no recharge was needed.
The circulator bath was refilled with 7 liters of Arrowhead distilled water and the unit was turned on. |
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Wed Sep 9 10:13:31 2009, steve, Bureaucracy, General, the use of FAX machine, scanner & toaster
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You said that the use of FAXST was forbidden for phds and graduate students. I had to swear on the promise of not ever buying an other FAXST |
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Fri Jun 29 11:02:00 2012, steve, Update, VAC, the vent is at 500 torr
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Quote:
Steve, Yuta and Jamie |
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Tue Jul 23 14:00:03 2013, Steve, Update, VAC, the vent is completed
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The 40m IFO has reached atmospher in 5 hours. It is ready to open chamber condition. The RGA is pumped with the maglev.
P1 pirani gauge is contact dependent as you see it on the linear plot It will be replaced during this vent.
The venting speed was 2-4 Torr / min |
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Wed Feb 24 09:06:25 2016, Steve, Update, Treasure, the way it happened
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Celebration
Quote:
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Thu Apr 16 16:37:42 2009, Alberto, Update, Auxiliary locking, the zipper
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It takes 18 months to double the computational power of microprocessors but it took man thousands of years to invent the zipper. I never really understood
that till these days.
Here is a sample of my latest results from Optickle simulations of the locking signal for the Power Recycling Cavity. |
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Thu Apr 16 17:19:44 2009, Alberto, Update, Auxiliary locking, the zipper
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Quote:
It takes 18 months to double the computational power of microprocessors but it took man thousands of years to invent |
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Thu Jul 11 09:24:03 2013, Steve, Update, General, there should be nothing left on optable tops
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| There are 4 oscilloscopes left on the AP optical table top.... It's only 25 lbs... Do not leave anything on the optical table tops! |
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Tue Feb 16 09:13:39 2016, Steve, Update, General, there was a power outage & EQ
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Pasadena reported the Sunday night event as a power transient caused by the trip of a power transmission line. This affected the entire city. Once the
loss was detected, the system automatically switches to an alternate source. It was about one second for the system to recover.
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Fri Sep 5 10:36:34 2008, steve, Update, PEM, thermostate setting changed
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Some one changed the thermostat (old control room ) setting behind 1Y6 from 73 to 79F
It should be in the elog.
The temp changed from freezing 20 to sunny 25 C |
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Fri Sep 5 15:09:50 2008, rana, Update, PEM, thermostate setting changed
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[quote]Some one changed the thermostat (old control room ) setting behind 1Y6 from 73 to 79F
It should be in the elog.[/quote]
In fact, it is.[FONT=Comic Sans MS] I demand satisfaction for the injury to my elogging reputation![/FONT] |
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Mon Sep 8 13:47:35 2008, steve, Update, PEM, thermostate setting changed
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[quote][quote]Some one changed the thermostat (old control room ) setting behind 1Y6 from 73 to 79F
It should be in the elog.[/quote]
In fact, it is.[FONT=Comic Sans MS] I demand satisfaction for the injury to my elogging reputation![/FONT][/quote]
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Thu May 1 17:14:36 2014, steve, Update, PSL, thin window AR measured
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CVI broadband AR coating was measured at the PSL-enclosure table around 9-10am today. The 2W Innolight first PBS S polarization beam was used with
an other 1/2 wave plate and PBS.
W2-PW1-1004-C-633-1064-0 This 0.045" thick window has 0.7- 0.8 % reflected beam on each sides at 5 degrees of incidence, P polarization. |
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Fri May 2 10:38:29 2014, steve, Update, PSL, thin window AR measured
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Quote:
CVI broadband AR coating was measured at the PSL-enclosure table around 9-10am today. The 2W Innolight first PBS S polarization beam |
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Fri Sep 30 16:17:10 2011, kiwamu, Update, Green Locking, things to be done for the Yarm green lock
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Thank you for the summary.
I think now you are getting into a phase where you should start doing some quantitative and careful checks.
1. Calculate how much light will be reflected from the cavity if the alignment is perfect. |
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Tue Oct 26 16:02:55 2010, yuta, HowTo, CDS, things to do after making a new Simulink model
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(Joe,Yuta)
Things to do after making a new Simulink model. |