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.
Large earthquake shakes Baja California, Mexico and 6 over Magnitude 5 aftershakes follow. The frontend computers are still down since Friday.
Steve and Koji (Friday, Apr 02)
Installation of ITMs are going on. Two new ITMs were placed on the optical table in the vacuum chambers. ITM for the south arm was put at the right place in accordance to the CAD drawing. ITM for the east arm is still at a temporaly place.
Tower placement (10:30-11:30)
- Put the tower on the table at a temporary place such that we can easily work on the OSEMs.
ITM (South arm) (14:00-16:30)
- Put the tower on the table at a temporary place such that we can easily work on the OSEMs.
- Leveled the table approximately.
- Released the EQ stops
- Removed anchors for the OSEM cables as it was too short. The wire distribution will be changed later.
- Put the OSEMs. Adjust the insertion to the middle of the OSEM ranges.
- Clamped the EQ stops again
- Placed the tower to the right place according to the CAD drawing.
- Released the EQ stops again.
- Check the OSEM values. The LL sensor showed small value (~0.5). Needs to be adjusted.
ITM (South) damping adjustment
- Found the signs for the facing magnets are reversed.
- Otherwise it damps very well.
The cabling on the seismic stack was rerouted so it could reach the south edge of the table: the cables were removed from the viton padded clamps and repositioned this morning.
ITM-south tower's earthquake screw viton tips could be a little bit larger. They do not stay in their screw hole after a hard clamping action.
4-40 earthquake screws under the test mass:viton tips can fall out without action, the treads are cross threaded so the screws are wobbling
This morning, at about 12 Koji found all the front-ends down.
At 1:45pm rebooted ISCEX, ISCEY, SOSVME, SUSVME1, SUSVME2, LSC, ASC, ISCAUX
Then I burtestored ISCEX, ISCEY, ISCAUX to April 2nd, 23:07.
The front-ends are now up and running again.
I restored damping to all SUSes except ITM-east. The ITMX OSEMs are being used in the clean assembly room.
In order to minimize the diffusion of more dust particles into the vented IFO vacuum envelope
BEFORE opening chamber:
-Have a known plan,
-Heavy 1" thick door requires 3 persons- of one experienced and one certified crane operator and steel tow safety shoes
-Block IFO beams, be ware of experimental set up of other hazards: 1064, visible or new-special installation
- Look at the particle counter, do not open above 6,000 particles of 0.5 micron. Construction activities are winding down. See plot of 35 days since we vented.
-Have clean door stand for heavy door, covered with merostate at the right location and dry-clean screws for light covers,
-Prepare lint free wipers for o-rings,(no solvent on o-ring!) Kimwipes for outside of chamber and metal covers, methanol and powder free gloves
-Wipe with wet Kimwipe-tissue of methanol around the door, chamber of interest and o-ring cover ring
-Cut door covering merostate and tape it into position,..if in place...check folded-merostate position, if dusty... replace it
-Is your cleanroom garment clean?.......if in doubt ....replace it
-Keep surrounding area free and clean
-Make sure that HEPAs are running: PSL-enclosure, two mobile units and south end flow banch
-Check the tools: are they really clean? wipe it with wet Kimwipe, do you see anything on the Kimwipe?
-You are responsible to close chamber ASAP with light door or doors as you finished for the day.
Merostate cover down is appropriate during daily brakes.
The 1979 vintage RF spectrum analyzer HP4195A sn2904J01587 shipped out for repair today to http://www.avalontest.com
It has a 25 MHZ oscillation when you go below 150 MHZ in your sweep....atm1 with the larger amplitude shows this 25 MHZ
Atm2 is displaying full sweep-sign scans from 1 to 500 MHZ.....here one can clearly see the three segment of the scan:
1, large amplitude 25 MHZ oscillation dominating the spectrum up to 150 MHZ
2, the mid section from 150 MHZ to 300 MHZ with medium size amplitude is normal
3, from 300 MHZ to 500 MHZ the amplitude is decreasing.......showing the disadvantage of using a 300 MHZ oscilloscope
We found ref-cavity HV was off yesterday afternoon. It was turned back on.
ETMY sus damping was restored
The 40m's new undergrad Kevin Kuns was introduced to 40m safety hazards. He is new and needs guidance as specially with 2W laser work.
Peter King will train him on Friday to LIGO-laser standard.
Koji and I wanted to turn off the IFO-room AC so the wind would not blow on MC1-3. We could not. The switches were probably bypassed when the power transformer was replaced at the last scheduled power outage.
There is one three position manual/off/auto switch next to the filter for each unit at CES. They have to be in AUTO position when we want to turn AC on/off from the lab.
Now I know why Rana was wearing his bright green pants yesterday. It is nice to see the green beam in the 40m IFO again. It calls for celebration!
I stopped AWG 1Hz drive of ITMYs (south-arm) I still see unblocked beams at the ETMYs table. We have plenty of cleaned razor beam traps to be used. Please block Faraday rejects etc
I stopped AWG 1 Hz drive to ITMYs. ITMXe was also driven or oscillating. ITMXe damping was off, so I turned it on. It did not effect it's oscillation
ETMY-south sus damping was restored
As we learned yesterday, the PSL laser power out put mechanical shutter is not working in the remote mode. It only works in local manual mode.
Do not rely on the MEDM screen monitor readout! The position is only changing on the monitor. The main beam must be blocked before the output periscope.
Ben found the Sorenson 5V ps off. It was turned off since our last scheduled power outage. I wonder what else is running on 5V in the PSL? This power supply should be on the
"alarm handler" list to avoid future repeat of this condition. However a real safety switch would have confirming position sensors of the shutter open or closed. Is there such thing at the sites?
[Jenne, Kiwamu, and Steve via phone]
Around 9:30pm, Kiwamu and I came back from dinner, and were getting ready to begin the beam scan measurements. I noticed that one of the vacuum pumps was being very loud. Kiwamu noted that it is the fore pump for TP3's turbo, which he and Steve replaced in January (elog 2538). We had not noticed these noises before leaving for dinner, around 8pm.
We called Steve at home, and he could hear the noise through the phone. He said that even though it was really loud, since it was reading 3.3mTorr (on the display of the controller, in the vacuum rack just above head-height) which is close to the nominal value, it should be fine to leave. He will check it out in the morning. If it had been reading at or above ~1Torr, that's indicative of it being really bad, and we would have needed to shut it off.
For future reference, in case we need to turn it off, Steve said to use the following procedure:
1. Close VM3, to isolate the RGA, which is what this pump is currently (while we're at atmosphere) pumping on. I don't know if there are other things which would need to be shut at this stage, if we were at vacuum nominal.
2. Close VM5, which is right in front of TP3, so TP3's pump is just pumping on itself.
3. Push the "Stop" button on the Turbo controller for TP3, in the vacuum rack, about waist level. Turning off the turbo will also turn off the fore pump.
UPDATE, 1am: The controller in the rack is reading 3.1mTorr, so the pump, while still noisy, still seems to be working.
The foreline pressure of TP3 is 2.9 mTorr The drypump is loosing it's bearing and it is very noisy.
V3, V5 closed and TP3 small turbo controller off. This turned off the noisy forepump that has to be replaced.
RGA is running at cc4 2e-6 Torr
The RGA was turned off at cc4 1e-5 Torr
Bob replaced the tipseal in an other drypump and I swapped it in. TP3 turbo is running again, it's foreline pressure is 40 mTorr. The RGA is still off
IFO room temp 27.5C , Please remember to turn AC back on !
Valera and I put the 2 Guralps and the Ranger onto the big granite slab and then put the new big yellow foam box on top of it.
There is a problem with the setup. I believe that the lead balls under the slab are not sitting right. We need to cut out the tile so the thing sits directly on some steel inserts.
You can see from the dataviewer trend that the horizontal directions got a lot noisier as soon as we put the things on the slab.
The tiles were cut out in 1.5" ID circle to insure that the 7/16" OD lead balls would not touch the tiles on Wednesday, May 26, 2010
Granite surface plate specifications: grade B, 18" x 24" x 3" , 139 lbs
These balls and granite plate were removed by Rana in entry log #3018 at 5-31-2010
This box was made to provide good thermal stability for seismometer calibration. There is an inner solid shell of 0.064" Al box that is covered by 2" insulation
inside and outside. The polystyrene foam is "CertiFoam 25 SE " from McMasterCarr #9255K3.
Is the cooling line clogged? The chiller temp is 21C See 1 and 20 days plots
Steve for Nancy,
Seismometer interface box ac power was turned off, Guralps disconnected and moved. Ranger locked, moved and released. Nancy will describe the rest soon.
The flattened lead balls were checked for their heights by the calliper, and were all in the range of 9.50 to 9.70 mm.
The rechecking was done by using these balls between two aluminium plates and checking their levelling. When confirmed this, we proceeded to install the balls(no more balls :P ) in their place.
The Guralps were switched off by switching off the power supply to them. The ranger mass was clamped in order to be able to move it. This can be undone by rotating the transport screw counter-clockwise.
We installed the flattened lead ballsin the space made for them. The granite was then placed on it with the help of many other people in the lab. It was lowered by hanging it on two straps held by people , and then placed in the space marked for it.
Did we then turn on the seismometers? Did we release the locking screw on the Ranger? What happened to Bat-Boy??? Since they make a good mystery I will choose to leave them out of my elog entry.
Nancy and Sharmila received introductory early bird surf safety training for the 40m lab.
The laser chiller temp is fluctuating and the power output is decreasing. See 120 days plot.
Yesterday I removed ~300cc water from the overflowing chiller tank.