 Tue Apr 9 14:55:13 2013, Jamie, Update, CDS, overbooked test points cause of DAQ problems 
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Folks were complaining that they were getting zeros whenever they tried to open fast channels in DTT or Dataviewer. It turned out that the problem
was that all available test points were in use in the c1lsc model:
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 Thu Jan 10 10:23:46 2019, gautam, Update, VAC, overnight leak rate
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Overnight, the pressure increased from 247 uTorr to 264 uTorr over a period of 30000 seconds. Assuming an IFO volume of 33,000 liters, this corresponds
to an average leak rate of ~20 uTorr L / s.
It'd be interesting to see how this compares with the spec'd leak rates of the Viton O-ring seals and valves/ outgassing rates. The two channels |
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Sat Feb 2 21:53:24 2019, Koji, Update, VAC, overnight leak rate
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The pressure of the main volume increased from ~1mtorr to 50mtorr for the past 24 hours (86ksec). This rate is about x1000 of the reported number on
Jan 10. Do we suspect vacuum leak?
Quote:
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Sun Feb 3 15:15:21 2019, gautam, Update, VAC, overnight leak rate
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I looked into this a bit today. Did a walkthrough of the lab, didn't hear any obvious hissing (makes sense, that presumably would signal a much larger
leak rate).
Attachment #1: Data from the |
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Sun Feb 3 20:52:34 2019, Koji, Update, VAC, overnight leak rate
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We can pump down (or vent) annuli. If this is the leak between the main volume and the annuli, we will be able to see the effect on the leak rate. If
this is the leak of an outer o-ring, again pumping down (or venting) of the annuli should temporarily decrease (or increase) the leak rate..., I
guess. If the leak rate is not dependent on the pressure of the annuli, we can conclude that it is internal outgassing. |
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Mon Jul 22 07:21:13 2019, gautam, Update, CDS, painosa messed with
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Somebody changed the settings on painosa without elogging anything about it. Why does this keep happening? I thought the point of the elog was to communicate.
I think there are sufficient number of problems in the lab without me having to manually reset the control room workstation settings every week. Please
make an elog if you change something. |
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Wed Feb 15 00:26:44 2017, Johannes, Update, DAQ, panels and pcbs
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I finished designing the PCBs for the VME crate back sides (see attached). The project files live on the DCC now at https://dcc.ligo.org/LIGO-D1700058.
I ordered a prototype quantity (9) of the PCB printed and bought the corresponding connectors, all will arrive within the next two weeks. See also attached
the front panels for the Acromag DAQ chassis and Lydia's RF amplifier unit (the lone +24V slot confuses me: I |
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Wed Feb 15 09:06:13 2017, ericq, Update, DAQ, panels and pcbs
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The amplifier unit should use the three pin dsub connectors (3w3?) that we use on many of the other units for DC power, and preferably go through the
back panel. You can leave out the negative pin, since you just need +24 and ground. |
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Wed Feb 15 22:21:12 2017, Lydia, Update, DAQ, panels and pcbs
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This is already how it's hooked up. The hole on the from that says +24 V is for an indicator light.
Quote:
The amplifier unit should |
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Sat Mar 5 01:58:49 2022, Koji, Summary, CDS, paola rescue
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ETMY end ThinkPad "paola" could not reboot due to "Fan Error". It seems that it is the failure of the CPU fan. I really needed a
functional laptop at the end for the electronics work, I decided to open the chassis. By removing the marked screws at the bottom lid, the keyboard was
lifted. I found that the CPU fan was stuck because of accumulated dust. Once the fan was cleaned, |
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Fri Sep 16 14:15:28 2016, steve, Update, PEM, partical counts
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South end flow bench and both clean room assembly flow benches measured zero counts for 0.3 and 0.5 micron size particales.
The counting efficiency of 0.5 micron is 100%
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Tue Nov 27 11:27:22 2012, Steve, Update, PEM, particle count is going up
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Jeff is still working on the filter banks. |
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Mon Nov 10 16:44:14 2008, steve, Update, PEM, particle counter at MC2
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The particle counter was moved to MC2 table temporarily.
It is clamped to the table at the south west corner.
It is pumping for 20s and waiting for 2 minutes now. |
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Mon Mar 20 17:12:08 2017, steve, Update, PEM, particle counter inside of PSL enclousure
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The logging script is multiplying by 100 instead of 10 !
Quote:
The MET#1 particle counter |
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Mon Mar 27 15:36:27 2017, Steve, Update, PEM, particle counter inside of PSL enclousure
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Quote:
The logging script is |
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Thu Aug 14 11:39:06 2008, steve, Update, PEM, particle counter is out of order
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| The 40m ifo paricle counter sensor failed last night. |
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Fri Feb 17 10:56:12 2017, steve, Update, PEM, particle counter moved into PSL enclousure
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The MET#1 particle counter was moved from CES wall at ITMX to PSL enclousure south west corner at 11am.
The HEPA filter speed at the Variac was turned down to 20V from 40
This counter pumps air for 1 minute in every 20 minutes. Soft foam in bags used to minimize this shaking as it is clamped. |
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Wed Sep 8 16:17:58 2010, steve, Update, PEM, particle counter problem
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I played with the particle counter this morning. Now it's running and reading the correct numbers on the old COCHECKLIST.adl medm screen.
However, it can not be seen with dataviewer.
Koji just rebooted the frame builder and the problem was solved. |
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Fri Aug 22 16:06:29 2008, steve, Update, PEM, particle counter replaced, flowbenches & HEPAs checked
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MetOne #2 counter was swapped in (on the top of IOC, facing SW direction, at ~75 deg upwards)
with channel one size 0.3 micron and channel two size 1.0 micron.
Sampling time was reduced from 60s to 6 sec at 0.1 cf/min at 25 min rate.
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Tue Oct 1 10:06:27 2013, Steve, Update, PEM, particle counts
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How can we improve the cleanliness
of the 40m IFO room 104 ? May be Mario Batali crocs if you chief chef of the lab likes it. We can do more effective things.
Atm 1 is showing the lab air quality dependence on outside air measured at the top of the IOO chamber. This made me to measure the |
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Tue Oct 1 11:24:02 2013, rana, Update, PEM, particle counts
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Probably more important is to establish quantitatively how particle counts affects the lock acquisition or noise in the interferometer.
We don't want to adopt a "Sky is Falling" mentality as was done previously in LIGO when people were trying to outlaw burritos and perfume.
Dust monitor counts and human noses do not correlate well with the interferometer's nose. |
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Thu Sep 3 10:19:35 2009, steve, alberto, Update, PEM, particle counts and burning hillsides
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The San Gabriel mountain has been on fire for 6 days. 144,000 acres of beautiful hillsides burned down and it's still burning. Where
the fires are.
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Wed Jun 10 09:06:12 2009, steve, Update, PEM, particle counts and turbulance
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I moved the mobile HEPA filter from ITMX's north door to ITMX-ISCT and covered it up with a merostate tent to accommodate the aluminum foil particle
measurement on June 5
It lowered the 40m baseline counts by about a factor of 3 of 0.5 micron and a factor of 2 of 1.0 micron. |
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Fri Mar 20 11:01:02 2009, steve, Update, PEM, particle counts are high
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The outside particle counts for 0.5 micron are 3 million this morning at 9am. Low clouds, foggy condition with low inversion layer.
This makes the 40m lab 30-50K
I just turned on the HEPA filter at the PSL enclosure. |
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Thu Nov 8 11:40:21 2007, steve, Update, PEM, particle counts are up
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I turned up the psl HEPA filter to 100%
This 4 days plot shows why |
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Wed Jun 6 15:12:29 2018, Kira, Update, PEM, parts from lab
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Got this 1U box from the Y arm that we could potentially use (attachment 1). It doesn't have handles on the front but I guess we could attach them
if necessary. Attachment 2 is a switch that could be used instead of a light up switch, but now we need to add LEDs on the front panel that indicate that
the switch is functional. Attachment 3 is a terminal block that we can use to attach the 16 gage wire to since it is thick and attaching it directly to |
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Thu May 24 16:08:12 2018, Kira, Update, PEM, parts list
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We will need to order a few things for our final setup.
1U box to place the heater circuit and temperature circuits in. The minimum depth that will fit all the electronics is 10 inches
according to my sketch.
I found two possibilities online for this. I don't know exactly what our budget is, but this |
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Tue May 29 16:22:43 2018, Kira, Update, PEM, parts list
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I've updated the parts list to be an excel document and included every single part we will need. This is ony a first draft so it will probably
be updated in the future. I also made a mistake in hole sizing for the front panel so I've updated it and attached it as well (second attachment).
Edit: re-attached the EX can panel fpd file so that everything is in one place |
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Mon Feb 11 18:44:34 2013, Jamie, Update, Computers, passwerdz changed
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Quote:
Be Prepared |
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Wed Sep 29 01:53:44 2010, rana, Update, PSL, paths broken and VCO turned off
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I found that several linux libraries have been moved around and disabled today. In particular, I see a bunch of new stuff in apps/linux/ and ezca tools
are not working.
Who did this and why is there no ELOG ???
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Thu May 14 00:47:55 2020, gautam, Summary, Computer Scripts / Programs, pcdev1 added to authorized keys on nodus
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This is to facilitate the summary page config fines to be pulled from nodus in a scripted way, without being asked for authentication. If someone knows of a better/more secure way for this to be done, please let me know. The site summary pages seem
to pull the config files from a git repo, maybe that's better? |
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Thu Jul 1 10:26:34 2010, steve, Configuration, VAC, pd68 at vacuum normal state
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Slow pump down _pd68 has reached the vacuum normal state. CC4_Rga region is pumped now. The RGA is still off.
Precondition to this pump down: &nb |
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Thu Jul 19 11:01:03 2018, Steve, Summary, VAC, pd81 @ 2e-5 Torr
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| Cold cathode gauge just turned on. |
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Wed Aug 20 11:42:49 2008, John, Summary, Computers, pdftk
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I've installed pdftk on all the control room machines.
http://www.pdfhacks.com/pdftk/ |
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Tue Aug 2 19:05:13 2011, kiwamu, Update, IOO, peparation for low power MC : HWP+PBS installed
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[Steve / Kiwamu]
An attenuator, consisting of two HWPs and a PBS, has been installed
on the PSL table for the MC low power state. |
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Wed Aug 3 04:29:48 2011, kiwamu, Update, IOO, peparation for low power MC : HWP+PBS installed
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[Suresh / Kiwamu]
The incident beam power going into MC was decreased down to 20 mW by rotating the HWP that we set
yesterday. |
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Tue Nov 4 01:03:01 2008, rana, Summary, PEM, periodic thump noise in MC1_ACC
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[B]There seems to be a periodic thump seen by the MC1 Accelerometers as well as the surrounding optics.[/B]
The first 5 hour minute-trend plot shows the periodic thumping as well as the one large saturating event which ruins the
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Tue Feb 21 08:33:16 2012, steve, Update, Green Locking, periscope adapter plate
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| Two extender plates ready for cleaning. The existing optical table tops have 38" OD. Using two of these the OD will be 44" |
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Thu Oct 16 13:12:58 2008, pete, Configuration, PSL, phase between FSS reference outputs
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| I verified the phase between the FSS reference outputs (used for LO and RF) using matched BNC cables. I measured 0.95 degree (average of 12 scope measurements). |
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Sun Sep 11 15:19:39 2011, kiwamu, Update, LSC, phase delay in RF signals
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A comment :
Since the LSC RFPD have a long cable of more than 6 m, which rotates a 33 MHz signal by more than 360 deg, so the delay has always existed in everywhere.
The circuit you measured is a part of the delay existing in the LSC system, but of course it's not a problem as you said. |
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Tue Sep 2 22:54:27 2014, Koji, Summary, LSC, phase tracker UGF
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FYI and FMI
Phase tracker UGF is Q_AMP * G * 2 PI / 360 where Q_AMP is the amplitude of the Q_ERR output and G is the gain of the phase tracker.
For example: Q_AMP = 270, G = 4000\ => UGF = 1.9kHz |
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Mon Jun 18 23:54:31 2012, yuta, Update, Green Locking, phase tracker for ALS
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[Koji, Jenne, Yuta]
Summary: |
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Sat Mar 2 20:09:12 2013, yuta, Update, RF System, phase tracker: DAQ noise limited
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[Koji, Yuta]
We found that our phase tracker noise is currently limited by the noise introduced in DAQ. |
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Sat Feb 16 18:32:01 2013, yuta, Summary, RF System, phase tracker: OLTF
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I measured openloop transfer function of the phase tracking loop for the first characterization of phase tracker.
What is phase tracker: |
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Thu Feb 28 05:54:54 2013, yuta, Update, RF System, phase tracker: calibration
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I swept the frequency of RF input to the beatbox to calibrate and check linearity range of phase tracker.
Calibration factors are;
C1:ALS-BEATX_FINE_PHASE_OUT 52.1643 +/- 0.0003 deg/MHz |
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Thu Feb 28 06:51:17 2013, yuta, Update, RF System, phase tracker: noise level
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I measured noise level of the phase tracker by inputting constant frequency RF signal from marconi.
Measured frequency noise was ~2 Hz/rtHz @ 100 Hz. It's not so good.
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Tue Jul 14 00:57:11 2009, Alberto, Update, Locking, photodiode alignment check
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Since lately the alignment of the input beam to the interferometer has changed, I went checking the alignment of the beam on the photodiodea. They were
all fine except for pd9, that is AS DD 199. Here the DC is totally null. The beam seems to go right on the diode but the scope on the PD's DC output shows
no power. This is really strange and bad. |
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Wed Jul 15 12:14:08 2009, Alberto, Update, Locking, photodiode alignment check
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Quote:
Since lately the alignment of the input beam to the interferometer has changed, I went checking the alignment of the |
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Wed Oct 2 23:21:54 2013, rana, Update, Computer Scripts / Programs, pianosa can't find Jamie PPA
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Message on 'pianosa':
Failed to fetch http://ppa.launchpad.net/drgraefy/nds2-client/ubuntu/dists/lucid/main/binary-amd64/Packages.gz 404 Not Found |
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Thu Oct 3 08:57:00 2013, jamie, Update, Computer Scripts / Programs, pianosa can't find Jamie PPA
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Quote:
Message on 'pianosa': |