RFAMPD_DCMON disappered on Nov 5, 2009
The concrete floor cutting has begun next door at CES
ATM1: Seismometers are saturating, suspensions are OK
Atm2 : activity next door, diesel Backhoe and diesel concrete cutter are running
Atm3: CES exhaust fans output is pick up by 40M-Annex-North AC unit intake. The 40m office room has some diesel smell...........see # 2377
I added ~500 cc of distilled water to the laser chiller yesterday.
8 days plot: Thurdsay, Friday, Sat and Sun without construction
This first plot shows the RC temperature channels' performance from 40 days ago, before we disabled the MINCO PID controller. Although RCTEMP is supposed to be the out of loop sensor, what we really care about is the cavity length and so I've plotted the SLOW. To get the SLOW on the same scale, I've multiplied the channel by 10 and then adjusted the offset to get it on the same scale.
The second plot shows a period after that where there is no temperature control of the can at all. Same gain scaling has been applied to SLOW as above, so that instead of the usual 1 GHz/V this plot shows it in 0.1 GHz/V.
The third plot shows it after the new PID was setup.
Summary: Even though the PID loop has more gain, the true limit to the daily fluctuations in the cavity temperature and the laser frequency are due to the in-loop sensors measuring the wrong thing. i.e. the out-of-loop temperature is too different from the in-loop sensor. This can possibly be cured with better foam and better placement of the temperature sensors. Its possible that we're now just limited by the temperature gradients on the can.
Here is a 7 years plot of of the 40m temperature variations.
I've changed the watchdog rampdown script so it brings the SUS watchdogs to 220, instead of the 150 it previously targeted. This is to make tripping less likely with the jackhammering going on next door. I've also turned off all the oplev damping.
Saturday's special event of braking up the large concrete pieces in CES bay was un event full.
Steve is summarizing the Video Matrix choices into this Wiki page:
Price: < 5k$
Control: RS-232 and Ethernet
Interface: BNC (Composite Video)
Please check into the page on Monday for a final list of choices and add comments to the wiki page.
Composite video matrix switchers with 32 BNC in and 32 BNC channels out are listed.
The construction activity is shaking the tables in the control room. The compactor- large remote controlled jackhammer is in the bottom of the 16-17 ft deep hole 15 ft east of ITMY in CES bay. The suspensions are holding OK. PRM, MC1 and MC3 are effected mostly.
Instead of doing RCG stuff, I went to Millikan to work on data analysis as I couldn't stand the fumes from the construction. (this morning, 8am)
Diesel fumes are pumped away from control room AC intakes with the help of newly installed reflector boxes on the CES wall fans.........see # 2272
The vacuum system is at 760 torr All chambers with doors on and their annuloses are pumped down.
PSL output shutter is still closed. We are fully prepared to star slow pump down tomorrow.
The plan is to reach 1 torr ~ in 6 hrs without a creating a sand storm.
Oplev positions before and after drag wiped arm TMs as of yesterday. Slow-mode pumpdown has started with 3/4 turn opened RV1 valve at 8am today.
Pump down is completed. Valve configuration is VACUUM NORMAL. CC1 pressure is in the ~8 e-5 torr PSL output shutter is opened.
We still had some ants visiting the sink area this morning. These ants seem to be addicted to our our Peet's coffe
Spectracide: Bug Stop insect killer was sprayed. Please wash your eating dishes well ! and keep area clean.
At ITMX, on the CES side, 5 Ft from the wall the jackhammer is on. The susses are holding well.
We have been waiting for this for 20 some years. Arrowhead water with cooler. AWESOME
I added 600 cc of Arrowhead Distilled Water to the chiller.
60 days plot shows that about every ~ 10 days I have to add some.
Please check the water level yourself.
We lost our key to the Lightwave 125/6-OPN-PS The key shop just made one look a like that works.
We are celebrating Rob's promotion to thesis poetry. These pictures were taken on December 9, 2009
Rob has finished all his measurements in the lab and is officially well prepared to graduate.
What was the power level, polarization and beam size at beam trap?
Rana noticed that recently the temperature inside the lab has been a little bit too high. That might be causing some 'unease' to the computers with the result of making them crash more often.
For the next hours I'll be paying attention to the temperature inside the lab to make sure that it doesn't go out of control and that the environment gets too cold.
Today the lab is perceptibly cooler.
The temperature around the corner is 73 F.
The 2W NPRO from Valera arrived today and I haf hidden it somewere in the 40m lab!
Rana was so kind to make this entry for me
CES construction is progressing. The 40m suspensions are bearing well.
atm1, PEM vs sus plots of 120 days
atm2, big pool walls are in place, ~10 ft east of south arm
atm3, 10 ft east of ITMY
atm4, ~60 ft east of ITMY
atm5, cold weather effect of N2 evaporator tower
The low PMC transmission alarm was on this morning. The PMC alignment needs a touch up.
The electrical shop has to connect the new power transformer at CES. This means we will have no AC power for ~8 hrs on Saturday, February 20
Is this date good for us to power down ALL equipment in the lab?
I have installed a slow start throttle valve in front of V3 This spring loaded valve will cut down on the flow at high pressures. There will be no more sand storme
and static built-up during pump down.
IN VACUUM beam heights are ALL 5.5" This is measured from the top of the optical table to the center of all TMs, mirrors and other optical components. This beam is ~36" above the floor.
PSL (inside of enclosure) main-output beam: PMC, MZ, RC and ISS are at 3" heights. IOO Angle & Position, MC-Trans and RFAM qpds are at 4"
ALL OTHER beam heights at atmosphere and different ISCT (interferrometer sensing, control optical table)s are at 4"
Joe and Alex are working on the computers. Our vacuum system is temporary "All off" condition: meaning all valves are closed, so there is no pumping. cc1 = 1.6e-6 Torr
Designated vacuum control lap top is trouble some to use. Joe finally fixed it and I switched valve configuration back to vacuum normal. Shutter is open
Only the 40m cranes are running on 480VAC The electricians are rewiring this transformer on the mezzanine so it was shut down.
I tested all three cranes before the 480V power was turned off. The last thing to do with the cranes to wipe them down before use.
It will happen on next Tuesday morning.
Our janitor dropped one 48" long fluorescent tube on the top cover of ETMX-isct. This accident made glasses fly all over the place.
He cleaned up nicely, but please beware of small glass pieces around ETMX chamber.
We did not clean up on the table in order to reserve oplev and green ITMX pointing alignment.
Plot below shows that the alignment was not effected.
As preparation for the upcoming planned power outage we turned turbos, RGA off and closed valves.
IFO chamber is not pumped now. Small leaks and out gassing will push the pressure up slowly. At 3 mTorr of P1 the PSL output shutter
will be closed by the interlock.
It is OK to use light in the IFO up to this point.
Our vacuum was not pumped for 4 days. The computers were not up when we started pumping again. The manual reading on P1 was 15 mTorr.
This means that our outgassing plus leakrate is ~3.8 mTorr /day
3-5 mTorr / day is normal
There is a planned power outage tomorrow, Saturday from 7am till midnight.
I vented all annulies and switched to ALL OFF configuration. The small region of the RGA is still under vacuum.
The vac-rack: gauges, c1vac1 and UPS turned off.
The 40m safety audit will be at Wednesday afternoon, March 3
Please participate getting our lab to inspection grade safety level.
Vac- rack is powered back up. UPS first, than all other power switches from top to bottom of the rack, except Maglev
Manually started one by one TP2 and TP3 to accelerate to 50 KRPM
Brought up vac.control screen on lap-top at /cvs/cds/caltech/medm/c0/ve/VacControl_BAK.adl
V5 and VM3 were opened so TP3 can pump on the RGA
V4 was opened so TP2 can pump on the Maglev-TP1. The Maglev power was turned on and started acceleration.
The vac control screen positions indicators were checked for true position and annulies vent valves were opened.
RGA manual on/off switch was turned at the top of the RGA-head. Ubuntu copmuter was started at cc4 1.1e-6 Torr
The RGA communication was started with: ssh c0rga from control room
The rga-script was started ./RGAset.py This script turns on the filament, rs-232 and scan parameters etc
Vac -configuration: IFO-P1 at atm, RGA is pumped and running in background mode, all annulos at atm
Jenne and Koji
We successfully hung ITMX on the SOS. Side magnet is ~2mm off from the center of the OSEM. ITMX aligned using the QPD. The OSEMs changes the alignment. It looks that something magnetic is inside the OSEM PD or LED.
Reguled ITMY side magnet.
Cleaned up the lab for the safety inspection.
The brand new OSEM LED and PD can be picked up with a weak magnet. These ferrous metals of LEDs and PDs will be magnetized by sitting in the sus next to the
magnets for years. I hanged optics with new OSEMs and never saw this effect before.
We have to demagnetize them.
They are sandblasting at CES: our particle counts are very high. DO NOT OPEN CHAMBER!
It turns out that we perfecly timed the big one
In the process of finding the signal of the big chilean earthquake I just realized that we were all off
RGA scan of rga-region only at day 18 This is the back ground of the rga with some calibration gas.
Do not open IFO vacuum envelope today! They are sandblasting again at CES
Guralp 2 centered.The mass position offsets are: E-W 0.05V, N-S 0V, Z 0.4V
Guralp 1: E-W -0.1V, N-S -0.25V, Z 0V measured, not adjusted
The GUR2_X channel has an offset. See plot below when seismometers are disconnected. This offset has to be removed.
NOTE: this huddle is on bad-soft ground-lenoleum tile from prehistoric Flintstone age
The oplev plots clearly show the alignment effect of this eq.
Someone adjusted the Guralp2 mass position last night??
There was more jackhammering this morning just about 20 ft north-west of the beamsplitter chamber, outside.
This is the first touch to the MC mirrors after the earthquake on 16th.
So far, I have aligned in Yaw such that the yaw peak is minimized.
This seal is good for daily use- operation only. The IFO has to be sealed with light metal doors every night so ants and other bugs can not find their way in.
Our janitor Kevin is mopping the hole IFO room floor area with 5% ant killing solution in water in order to discourage bugs getting close to our openings of the vented chamber.
You may be sensitive to this chemical too. Do not open chamber till after lunch.
Old control room air condition failed yesterday around noon. It was blowing 80-85F hot air for about 2-3 hours at racks 1Y4-7 and the entry room 103
I went and double-checked and aligned the styrofoam cooler at ~5:00 UTC. It was fine, but we really need a better huddling box. Where's that granite anyway?
Here's the new Huddle Test output. This time I show the X-axis since there's some coherence now below 0.1 Hz.
You'll also notice that the Wiener filter is now beating the FD subtraction. This happened when I increased the # of taps to 8000. Looks like the noise keeps getting lower as I increase the number of taps, but this is really a kind of cheat if you think about it carefully.
The same thing happening again. The intermittent offset upstream of the seismometer that never got fixed.
The granite plate and ball bearings are in. I will place seismometers on it.
Safety glasses 1064 nm transmission measured at ~200 mW level. They are all good.
Some more words about the RFAM: I noticed that there was an excess RFAM by unlocking the RC and just looking at the RF out with the 50 Ohm input of the scope. It was ~100 mVp-p! In the end our method to minimize the AM was not so sensible - we aligned the waveplate before the EOM so as to minimize the p-pol light transmitted by the PBS cube just ahead of the AOM. At first, this did not minimize the RFAM. But after I got angry at the bad plastic mounting of the EOM and re-aligned it, the AM seemed to be small with the polarization aligned to the cube. It was too small to measure on the scope and on the spectrum analyzer, the peak was hopping around by ~10-20 dB on a few second timescale. Further reduction would require some kind of active temperature stabilization of the EOM housing (maybe a good SURF project!).
For the EOM mount we (meaning Steve) should replace the lame 2-post system that's in there with one of the mounts of the type that is used in the Mach-Zucker EOMs. I think we have spare in the cabinet next to one of the arms.
After the RFAM monkeying, I aligned the beam to the RC using the standard, 2-mirror, beam-walking approach. You can see from the attached plot that the transmission went up by ~20% ! And the reflection went down by ~30%. I doubt that I have developed any new alignment technique beyond what Yoichi and I already did last time. Most likely there was some beam shape corruption in the EOM, or the RFAM was causing us to lock far off the fringe. Now the reflected beam from the reference cavity is a nice donut shape and we could even make it better by doing some mode matching! This finally solves the eternal mystery of the bad REFL beam (or at least sweeps it under the rug).
At the end, I also fixed the alignment of the RFPD. It should be set so the incident angle of the beam is ~20-40 deg, but it was instead set to be near normal incidence ?! Its also on flimsy plastic legs. Steve, can you please replace this with the new brass ones?
Teflon feet removed and heavy brass-delrin pd base installed. Ref-cavity reflected light remains to be beautiful doughnut shape on camera.