PSL shutter closed, manual block in place, HV turned off. P1 is at 200 Torr now. Jenne is taking over here.
Valves closed, 500 torr. Steve will finish off Monday morning, then we'll take off doors and get to work.
We are almost at atm. P1 750 Torr, We are slowly reaching equilibrium.
The access connector was removed, BS and ITMY chambers were opened yesterday.
New one piece aluminum shell access connector installed. Jenne lowered the PSL out put into MC to ~100mW
Tip Tilt pitch adjustment on existing-in vacuum suspension. This can be added by a simple installation of a 1.25" long 2-56 threaded rod with nuts.
We should check that their sus wire diameter are 0.0017" All 2-56 hardware are in and Bob is cleaning them.
PR1, PR2 and RP3 turned on for warming up for oil change. Oil changed with 3.2L of MVT-19 fluid in each. This substitute for HE-175 will be used next time.
To finish this job tomorrow: 1, check oil creeping upstream 2, change air filter of air purge if pressure drops <350 mTorr 3, measure venting time of pump
. Leybold D30A manual is here. Exhaust filter traps were drained. No oil creeping was found. The pump venting time is < 1 minute.
PR-2 needs new secu-valve. PR1 & 2 are in excellent condition.
Apparently all of the ION pump valves (VIPEE, VIPEV, VIPSV, VIPSE) opened, which vented the main volume up to 62 mTorr. All of the annulus valves (VAVSE, VAVSV, VAVBS, VAVEV, VAVEE) also appeared to be open. One of the roughing pumps was also turned on. Other stuff we didn't notice? Bad.
Several of the suspensions were kicked pretty hard (600+ mV on some sensors) as a result of this quick vent wind. All of the suspensions are damped now, so it doesn't look like we suffered any damage to suspensions.
CLOSE CALL on the vacuum system:
Jamie and I disabled V1, VM2 and VM3 gate valves by disconnecting their 120V solenoid actuator before the swap of the VME crate.
The vacuum controller unexpectedly lost control over the swap as Jamie described it. We were lucky not to do any damage! The ion pumps were cold and clean. We have not used them for years so their outgassing possibly accumulated to reach ~10-50 Torr
I disconnected_ immobilized and labelled the following 6 valves: the 4 large ion pump gate valves and VC1, VC2 of the cryo pump. Note: the valves on the cryo pump stayed closed. It is crucial that a warm cry pump is kept closed!
This will not allow the same thing to happen again and protect the IFO from warm cryo contamination.
The down side of this that the computer can not identify vacuum states any longer.
This vacuum system badly needs an upgrade. I will make a list.
While I was doing the oil change of the roughing pumps I accidentally touched the 24 V adjustment knob on the power supply.
All valve closed to default condition. I realized that the current indicator was red at 0.2A and the voltage fluctuated from 3-13V
Increased current limiter to 0.4A and set voltage to 24V I think this was the reason for the caos of valve switching during the VME swap.
The thinner wire has a history that it did not improve the hysteresis (ask Jenne). Nevertheless, it's worth to try.
If you flip the clamp upside-down, you can lift the clamping point up. This will make the gravity restoring torque stronger.
(i.e. Equivalent effect to increasing the mass)
Luckily (or unluckily) the clamp has no defined location for the wire as we have no wire fixture.
Therefore the clamp will grab the wire firmly even without milling.
The wire clamps should be taken off at the top and at the mirror holder. They need a mill touch up. It would be nice to have the centering jig from LLO for the 0.0017"
The clamps in this condition are really bad. It can sleep, it is not adjustable.
We really need something better to replace the access connector when we're at air. This tin foil tunnel crap is dumb. We can't do any locking in the evening after we've put on the light doors. We need something that we can put in place of the access connector that allows us access to the OMC and IOO tables, while still allowing IMC locking, and can be left in place at night.
It is in the shop. It will be ready for the next vent. Koji's dream comes through.
24" diameter clear acetate access connector is in place. The 0.01" thick plastic is wrapped around twice to insure air and bug tight barrier for the MC to lock overnight. The acetate transmission for 1064 nm is 90 % This was measured at 150 mW 2.5 mm beam size.
Aluminum sheet as shown will replace the acetate. Side entries for your arms and "window" on the top will be covered with acetate using double- sided removable-no residue tape 3M 9425
The second loop of the bungee cord should be on the top of the acrylic and still on the supporting aluminum tube as shown.
High particle count confirmed with #2 counter
Suprema- SS clear edge mirror mount 2" diameter is modified for 40m vacuum use. One left and one right handed one. It's adjustment screw housing is bronze! It is not ideal for out gassing.
It will be baked and scanned. If it passes we should use it.
We may need these to bring out some pick-off beams.
I vote against it. We don't know about the grease inside the screw bushings - scans are not everything if adjusting the screw loosens up the grease. If we need more pick off mirrors lets just make some of the kind that we already use inside for the 2" optics.
I think Steve had these prepared in response to my question a few days ago of how badly do we need adjustability for the POX/POY mirrors? We already have cleaned open-sided mounts that have no adjustment screws. So as long as the beam reflects off the ITMs horizontally (which it should), we can do yaw adjustment by twisting the whole mount. We don't need super fine yaw adjustment, we just need to get the beam out, so this is probably good enough.
We should put the POY mirror on this open-sided mount (the one without screws) some time. Perhaps even today.
The hex adjustment screw is removed from the brass bushing for degreasing, cleaning and baking. Newport says the bushing is is brass not bronze.
Brass outgassing rate is 10x higher than copper that is truth. The surface area is small so Krytox grease is ok if it is really needed in the 40m. ( It was ok in the past and it is still there )
I asked Jamie to read these docs so we can do some troubleshooting while at atmosphere. We have to have the all valve closed DEFAULT condition working-tested.
I'd like to reconnect all valves after this test so the state identification software could work, including interlocks.
Posted the following documents on 40m wiki.
PRM and SRM OSEM LL 1.5V are they misaligned?
The BS camber is open only. We should close ASAP
Outside air quality is 1.7- 2.2 million particles / cf min of 0.5 micron
Air is still bad and the chambers are closed. Before lunch Jamie repointed the PRM oplev. Manasa and I reset oplevs: BS and ITMX.
ETMX and ETMY are fine.
SRM and ITMY oplevs needs more work.
We have two ready for vacuum 1.5" mirror mounts with pico motors in our hands.
Canon EOS Rebel T3i has been purchased. See rating
Oplevs and IP ANG are still centered. Why do the SRM and PRM move 5X more ? I could not check the sensing voltages because the computer failed.
AS and REFL are looking the same as last night.
ALL LOOKING GOOD!
I'm looking for IOO steering mirror power supplies. I found two so far: one at 1Y3 as Kepco + 75V and one at OMC_North rack -150V
Are there any more? The OMC is off.
ANSWER: only one of the steering PZT can be driven, so see their power supplies
The pressure is CC1 3e-4 Torr at 8 hours of pumping. Status: vacuum normal
The IFO is ready for light
Charles Blakemore our new undergrad help received 40m specific safety training today.
New Lumitek IR Sensor Cards are here. We got 2 pieces of Q-11-T (2" x 2"), 2 pieces of Q-11-T (0.75" x 0.75") and one Q-11 (4" x 5")
Air conditioning maintenance is scheduled for tomorrow morning till noon.
It took 15 days to reach 1e-5 Torr
The RGA was turned on yesterday. The rga scan plotting was not working. Den wrote a Python script to log and plot because the Mathlab had trouble receiving data from our old c0raga.
It turned out that the Joe's log&plot system was working today. Thanks Den and Joe.
Here is the first rga scan.
Jeff is still working on the filter banks.
Spare optics from the AP table were moved to glass cabinet in the east arm. I'm not sure this is the right place. We'll see what everybody thinks.
There were two UNMARKED optics. Shame on you! No pencil marks on the optics either. These optics were shipped to the FBI for finger tip analysis.
Clean cabinet S15 doors were left open. You have to lock it up!
Aluminum foil replaced by sheet metal on Enclosure and AP table.
For those of you who like to do work on the interferometer without reporting it in the elog because you think that what you did doesn't affect anything, this is your example of how our time can be wasted by such laziness.
I'm taking full responsibility for this action and I told them after lunch Friday.
HOW NOT TO:
The BS isolation stack supported by two beam tubes and they can pivot around the pivot point.
I've put EM 172 microphones inside Steve's isolation box to measure their noise. I've attached mics to each other and aligned them using the tape.
At low frequencies (below 1 Hz) the noise is limited by ADC as there is a 10 Hz high-pass filter inside mic readout box.
ADC noise is measured by splitting the signal from 1 mic into 2 ADC channels.
BT EM172 microphones are ordered.
CALIFORNIA INSTITUTE OF TECHNOLOGY
Date: Thursday October 04,2012
This morning at 2:17 a.m. much of the City of Pasadena including our Campus experienced a electric power sag of short duration, approximately 1/10 of a second. The cause was a fault on one of Pasadena’s 17KV circuits. Some sensitive equipment have been impacted.
Contact: Mike Anchondo x-4999
PRM oplev gains set to zero from PIT 0.15 and YAW -0.3 and damping restored
How NOT to:
The janitor can not clean in areas like this. He may only steps on these cables accidentally as he dust wiping our chambers.
The 40m vacuum envelope is at atm It took 4.5 hours at ~3 Torr/min speed. Atm1
What I did:
Turned PZT voltages off: 84.1V at OMC-rack location
- 99V at 1Y3 location as PZT_pitch,
56.6V KEPCO at 1Y3 location as PZT_yaw
Took screen shuts of SUS_SUMMARY, yesterday, Atm3
Turned off OPLEV _SERVOs, today , Atm2
Closed PSL_SHUTTER and green shutters at the ends
Set vacuum valves for vent position and opened VM2 for the RGA
Just in case we want to retrofit the Tip/Tils with Beryllium Copper wire, here are links to a few sources which have a supply of the right composition and temper:
I don't think its worth it to do something to modify them unless we get a real reduction in the hysteresis - need a benchtop test setup ASAP.
Be Copper in the lab is from Ca Fine Wire : alloy 10 CDA 17 in sizes .008" & 0.002" There are other sus wire choices in the Drever lab
Koji, Manasa, Jenne, Jamie, Bob and Steve
Access connector removed this morning and work has began in the IOO chamber. BE WARE OF ANTS !
We've been trying to figure out the connector for the TTs. Since, we found the cables were plugged in wrong in TT1; when triggered in pitch, the mirror moves in yaw and viceversa.
Referring to the cabling diagram, D1000234-v10, we infer that connectors go as J2 - LR, J3 - UR, J4 - LL, J5 - UL and the connections are made looking at the mirror from behind.
The view looking at the optic from the back:
Accu-Glass is closed till Jan 2, 2013
Atm2 would be the ideal solution Gender Adaptor Special with male - female sides and vented D-sub. How many are we getting 2 or 6 ?
The PMC PZT voltage slider seemed sticky. First it would not do anything, than after moving slider back an forth a few times, it had a range of 60V and later it had full range and it locked
PRM oplev servo turned off. OLPIT servo gain 0.15 and OLYAW -0.3 set to ZERO. PRM damping restored
The COVAC_MONITOR.adl was changed. Ion pump labeled as disconnected means: ion pump controller power turned off and ion pump gate valve control connection disconnected.
RP2 roughing pump labeled disconnected means: hardware disconnected.
The actual operational, valve control screen has not been changed yet.
Please wipe, clean car wheels and wear booties entering the 40m lab.
Obviously this person has no idea about our clean room rules.
The corrected drawing base for tip tilt with coils are going to the shop. The will be back by the end of the week.
Koji's design of the SS 2" mirror holder with flexure spring optic retainer like Polaris-K1 has been ordered. We are getting just one to see it's effect on the hysteresis.
Reminder: I will be on vacation next week. We would have to put the access connector in tonight if I'm pumping down Friday, tomorrow.
ETMX sus damping restored. It is still noisy
RGA background with VM2 open to Maglev at day 37
Note: The PAN gauge of the annulos is at atm. Please do not vent this 200 ft long annulos line when you venting the annulos of a chamber. The chamber annulos should be closed off to this long 2" OD. pipe before you vent the annulos of a chamber.
The wood exteier walls, gutters and doors were painted at CES-Annex building #69