I misaligned ITMX pitch on Friday and brought out the beam at 44" height. The beam was bouncing to much. I only realized it this morning why. The OSEM voltages are 1.8, 1.7, 0.2 and 0.9V Even with a stable 8-9 mm diameter beam you would be clipping
on the beam scanner 9 mm aperture. You can bring out the beam with one mirror right after PR3, just remove PRMOP2
We conducted a beam scan on the AP table of the AS beam. We used a lens to focus the beam onto a power meter, and slowly moved a razor blade across the beam using a micrometer, vertically and horizontally both in front of and behind the beam. We also had to block the beam next to the AS beam in order to do this, but is unblocked now. Mike will begin curve fitting the data to try and see if there is a different spot size given by the x-axis vs. the y-axis, and if the lens has any effect.
Eric Quintero and Mike Jenson received 40m specific basic safety training.
Summary: Recorded the presence of higher order modes in IMC
What I did: Misaligned the flat mirror MC1 by small amount in both pitch and yaw (it was needed to be done cause at the beginning of the experiment no higher order modes were present) and scanned the cavity for frequency-range 32MHz to 45MHz.
I found the presence of higher order modes around 36.7MHz (1st order) and 40.6MHz (2nd order) along with two other strong modes near 35MHz and 42.5MHz.
Please, restore condition after you finished and update elog right away! People wasted hours yesterday not knowing the condition of the MC
After looking at the in-vacuum layout I think we should make two changes during the next vent:
1) Reduce the number of mirrors between the FI and its camera. We install a large silvered mirror in the vacuum flange which holds the Faraday cam (in the inside of the viewport). That points directly at the input to the Faraday. We get to remove all of the steering mirror junk on the IO stack.
2) Take the Faraday output (IFO REFL) out onto the little table holding the BS and PRM Oplevs. We then relocate all 4 of the REFL RFPDs as well as the REFL OSA and the REFL camera onto this table. This will reduce the path length from the FI REFL port to the diodes and reduce the beam clutter on the AS table.
There is just so much room on this table.
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.
SOS alignment tool with ID 9.5 and 6.3 mm
The SP table was found open this morning. Please, do not make optics dirty!
I cleaned up the tops of the SP table.
Stop storing your junk, boxes, laptops, etc. on the optical tables. This includes the big SP table. Please move all of that junk into racks or shelves, etc.
The IFO will be at atmosphere overnight. The annuloses are pumped down. The access connector jam nuts are tightened to 45 ft/lbs
Actual pumpdown will start tomorrow morning.
IFO P1= 1mTorr, CC1 = 5e-4 Torr. The IFO is ready for work. Be free to open the shutter and turn on HV
Jenne will double check the MC -REFL path for 1W power. There is a manual block on the PSL table.
Atm1, Pirani gauge at 9 h 10 min
Atm2, Pump configuration of pd#73 at 9h 35 min
The new cold cathode gauge CC1 is in place. We were at atmosphere for 28 days ......more later
[Koji, Steve, Den]
TT alignment is fine, yaw damping is satisfactory, pitch damping is slow. We might want to add magnets to the mirror and attach blades to the frame for pitch edge current damping.
We are moving towards electronics testing.
Atm1, TT 1.5" high adaptor base will be back from the shop in 10 days.
Atm2, There is no PITCH damping, YAW edie current damping works well at 0.5 mm gap
Atm3, Adjustable Al -disc that contains a small magnet is purely designed.
We have to come up with a solution to have damping in PITCH
Jenne, Mike and I installed all of the post holders we could today including: REFL11, REFL33, REFL55, AS55, MCRef, POX11 and POP55. We did not install AS110, POY or REFL165 because there are interferences that will require moving stuff around. We also did not mount POP22 because it is a peely wally ThorLabs PD that will be replaced by a strong, straight and right thinking LIGO PD in the fullness of time. We did move it out of the way however which is no more than it deserves. Next step this afternoon Mike and I will install all of the telescopes and launching hardware. Then with the help of Steve we will begin routing the fibers. The 1x16 splitter module will be here by next Monday, the laser by the following Friday and then we will light up the fibers.
I'm proposing split loom tubing that would run in the cable tray to protect the fibers inside of it. This tubing diameter in the cable tray can be 1.5-2" and out of the tray 0.75"
Where is IP-ANG ? It is good practice to use two mirrors at launching and detecting the beam, so you can walk it - precisely adjust it.
The window can be replaced at ~$1,500 ea. 10 weeks as optical quality BK7 with dual AR
cc1 = 2.3e-5 Torr at day 6 vacuum normal
This is the third morning in a row that the MC2 was tripped. Would you look at it Koji?
Den Martynov received 40m specific safety training.
We observed one or two ants climbing over PMC optics without booties and safety glasses.
The floor was mopped with strong Bayer Home Pest Control solution in the Vertex area.
Do not work inside the 40m lab if you are sensitive to chemicals!
The SOS coil drivers (Atm2) were moved from 1X1 to 1Y2 location. Is this the best place to locate the IOO Tip-Tilt steering that will replace the PJ-PZT ?
See 40m wiki T-T
There had to be a power outage. Laser and air condition turned back on. The vacuum is OK
Sorensen DC power supplies were tripped, so they were reset: at AUX OMC South 18V and 28V for RF PS and at 1X1 24V
Power Outage confirmed:
** Notification **
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
All the front end machines are back up after the outage. It looks like none of the front end machines came back up once power was restored, and they all needed to be powered manually. One of the things I want to do in the next CDS upgrade is put all the front end computers in one rack, so we can control their power remotely.
c1sus was the only one that had a little trouble. It's timing was for some reason not syncing with the frame builder. Unclear why, but after restarting the models a couple of times things came back.
There's still a little red, but it mostly has to do with the fact that c1oaf is busted and not running (it actually crashes the machine when I tried to start it, so this needs to be fixed!).
The RGA was not effected by the short power outage.
40 plus freshmen visited the 40m today
1) Mirror mount holder for "large silvered mirror" inside of the 8" OD tube vacuum envelope.
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
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 can only decide the need of pitch damping when the coils are activated.
VME crate blew its fuse and the fuse housing is hard to access.
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.
Ayaka Shoda, visiting graduate student received basic 40m specific safety training today
ETMX optical table was left open. Burned toast award goes to ......?
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 at the next oil change - it has 1E-6 Torr vapor pressure.
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
Pitch damping solution needed! It should be in the machine shop already.
We observed one or two ants climbing over PMC optics without booties and safety glasses.
The floor is mopped again with strong PEST CONTROL SOLUTION in water in the Vertex area.
Do not plane to work in the IFO-room till noon if you are sensitive to chemicals!
I purchased 3x 1/2" ccd cameras and 3x F 50 mm lenses for the lab.
The spectral sensitivity plot is for an older model 902H. This new model has better sensitivity
VENT NOW and FIX ALIGNMENT!
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
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.
. 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.
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.
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 )