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ID Date Authorup Type Category Subject
  7369   Mon Sep 10 08:50:35 2012 SteveUpdateGeneralBeam scan measurement plan - to do Monday morning.

 

 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

  7373   Wed Sep 12 08:16:49 2012 SteveConfigurationPEMchamber must be sealed overnight!

Quote:

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.

 The vacuum envelope must be sealed with light doors on o-rings to insure a bug free IFO.  This was a violation!

  7374   Wed Sep 12 11:33:49 2012 SteveUpdateSAFETYsafety training

Eric Quintero and Mike Jenson received 40m specific basic safety training.

  7378   Thu Sep 13 07:36:41 2012 SteveUpdateGeneralrestore conditions

Quote:

 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

  7398   Mon Sep 17 18:04:01 2012 SteveUpdateCOC2 Layout Changes

Quote:

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.

Attachment 1: IMG_1635.JPG
IMG_1635.JPG
  7407   Wed Sep 19 09:24:01 2012 SteveOmnistructureIOOaccess connector at athmoshere

Quote:

Quote:

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.

 

Attachment 1: IMG_1641.JPG
IMG_1641.JPG
Attachment 2: IMG_1642.JPG
IMG_1642.JPG
Attachment 3: acetateAC.png
acetateAC.png
  7408   Wed Sep 19 09:32:24 2012 SteveUpdateSUSalignment centering jig

SOS alignment tool with ID 9.5 and 6.3 mm

Attachment 1: IMG_1639.JPG
IMG_1639.JPG
Attachment 2: IMG_1651.JPG
IMG_1651.JPG
  7431   Mon Sep 24 10:27:50 2012 SteveOmnistructureGeneraldo not leave stuff on optical table tops

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.

  7434   Mon Sep 24 17:47:05 2012 SteveUpdateVAC ready to pump

  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.

  7438   Tue Sep 25 17:21:01 2012 SteveUpdateVACpumpdown completed

 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

 

Attachment 1: pd73.png
pd73.png
Attachment 2: pd73b.png
pd73b.png
  7441   Wed Sep 26 11:03:04 2012 SteveUpdateVACpumpdown completed

 The new cold cathode gauge CC1 is in place. We were at atmosphere for 28 days ......more later

 

Attachment 1: 40mpd73md1.png
40mpd73md1.png
Attachment 2: 28datm.png
28datm.png
  7446   Thu Sep 27 15:21:04 2012 SteveUpdateSUSTT height adaptor & PTICH damping

Quote:

  [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

Attachment 1: 09271201.PDF
09271201.PDF
Attachment 2: IMG_1656.JPG
IMG_1656.JPG
Attachment 3: IMG_1654.JPG
IMG_1654.JPG
  7447   Thu Sep 27 16:26:11 2012 SteveUpdateLSCRF fibre protection in cable trays

Quote:

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"

 

  7451   Fri Sep 28 07:49:30 2012 SteveUpdate40m UpgradingNew ETMX layout - Version 1.0

  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

  7453   Mon Oct 1 07:25:48 2012 SteveUpdateSUSMC2 & ETMX sus damping restored
  7454   Mon Oct 1 09:02:17 2012 SteveUpdateVACpumpdown reached vacuum normal

Quote:

 The new cold cathode gauge CC1 is in place. We were at atmosphere for 28 days ......more later

 

 cc1 = 2.3e-5 Torr at day 6 vacuum normal

Attachment 1: pd73md6.png
pd73md6.png
Attachment 2: pd73md6b.png
pd73md6b.png
  7460   Tue Oct 2 07:45:49 2012 SteveUpdateSUS MC2 & PRM sus damping restored
  7461   Tue Oct 2 09:13:16 2012 SteveUpdateVACRGA scan at day 7

Quote:

Quote:

 The new cold cathode gauge CC1 is in place. We were at atmosphere for 28 days ......more later

 

 cc1 = 2.3e-5 Torr at day 6 vacuum normal

 

Attachment 1: pd73md7.png
pd73md7.png
  7466   Wed Oct 3 07:41:23 2012 SteveUpdateSUS MC2 sus damping restored

This is the third morning in a row that the MC2 was tripped.  Would you look at it Koji?

  7467   Wed Oct 3 11:43:33 2012 SteveUpdateSAFETYsafety training

Den Martynov received 40m specific safety training.

  7468   Wed Oct 3 15:37:04 2012 SteveUpdatePEMants on the PSL table

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!

 

Attachment 1: IMG_1690.JPG
IMG_1690.JPG
  7469   Wed Oct 3 15:58:57 2012 SteveConfigurationIOOSOS coil drivers moved

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

Attachment 1: SOScoildriversTT.jpg
SOScoildriversTT.jpg
Attachment 2: IMG_1680.JPG
IMG_1680.JPG
  7476   Thu Oct 4 08:39:58 2012 SteveUpdateGeneralpower outage

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

                 FACILITIES MANAGEMENT

 

**PLEASE POST**

 

 

Building:         Campus

 

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

 

Attachment 1: Oct4R2012.png
Oct4R2012.png
  7491   Fri Oct 5 14:40:55 2012 SteveUpdateVACRGA scan after power outage

Quote:

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.

Attachment 1: afterpoweroutaged10.png
afterpoweroutaged10.png
Attachment 2: pd73m10d.png
pd73m10d.png
  7493   Fri Oct 5 16:21:48 2012 SteveUpdateGeneralfreshmen visiters

40 plus freshmen visited the 40m today

Attachment 1: IMG_1693.JPG
IMG_1693.JPG
Attachment 2: IMG_1694.JPG
IMG_1694.JPG
  7510   Tue Oct 9 09:29:10 2012 SteveUpdateIOOthis is where we are

Quote:

Quote:

 The new cold cathode gauge CC1 is in place. We were at atmosphere for 28 days ......more later

 

 cc1 = 2.3e-5 Torr at day 6 vacuum normal

 

Attachment 1: 15days.png
15days.png
  7517   Wed Oct 10 08:36:47 2012 SteveUpdateCOCspecial mirror mounts holder

Quote:

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.

1)  Mirror mount holder for "large silvered mirror" inside of the 8" OD tube vacuum envelope.

Attachment 1: 10101201.PDF
10101201.PDF
  7518   Wed Oct 10 10:55:56 2012 SteveOmnistructureIOOaccess connector at athmoshere

Quote:

Quote:

Quote:

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

Attachment 1: 10101202.PDF
10101202.PDF
  7528   Thu Oct 11 11:36:52 2012 SteveUpdateSUSTT pitch adjustment

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.

Attachment 1: IMG_1702.JPG
IMG_1702.JPG
  7535   Fri Oct 12 10:39:45 2012 SteveUpdateSUSTT PITCH damping

Quote:

Quote:

  [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

 We can only decide the need of pitch damping when the coils are activated.

Attachment 1: IMG_1709.JPG
IMG_1709.JPG
  7545   Mon Oct 15 08:12:45 2012 SteveUpdateVACblank vac monitor

VME crate  blew its fuse and the fuse housing is hard to access.

Attachment 1: blankvac.png
blankvac.png
  7549   Mon Oct 15 17:08:01 2012 SteveUpdateVACvacuum is back with some disabled valves

Quote:

Quote:

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.

Attachment 1: VMEcrateout.png
VMEcrateout.png
Attachment 2: IMG_1725.JPG
IMG_1725.JPG
Attachment 3: warning.png
warning.png
Attachment 4: shortcomings.jpg
shortcomings.jpg
  7559   Tue Oct 16 17:06:47 2012 SteveUpdateSAFETYsafety training

Ayaka Shoda, visiting graduate student received basic 40m specific safety training today

Attachment 1: IMG_1735.JPG
IMG_1735.JPG
  7563   Wed Oct 17 08:01:54 2012 SteveUpdateGeneraldo not leave op-table open

ETMX optical table was left open. Burned toast award goes to ......?

  7564   Wed Oct 17 08:04:31 2012 SteveUpdateVACRoughing pumps on for oil change

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

  7566   Wed Oct 17 08:30:49 2012 SteveUpdateSUS PTICH damping needed

Quote:

Quote:

  [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

 Pitch damping solution needed! It should be in the machine shop already.

  7567   Wed Oct 17 09:01:37 2012 SteveUpdatePEMants on the PSL table

Quote:

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 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!

  7576   Thu Oct 18 15:36:57 2012 SteveUpdateCamerasWatec cameras & Tamron lenses

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

Attachment 1: 10181201.PDF
10181201.PDF
  7582   Fri Oct 19 16:45:39 2012 SteveUpdateVACvent has started

Quote:

 

 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.

  7587   Mon Oct 22 09:10:07 2012 SteveUpdateVAC@750Torr

Quote:

Quote:

Quote:

 

 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.

Attachment 1: ventOct222012.png
ventOct222012.png
  7594   Tue Oct 23 08:45:00 2012 SteveUpdateVACvent day 3

Quote:

Quote:

Quote:

Quote:

 

 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

Attachment 1: ventd4.png
ventd4.png
Attachment 2: IMG_1743.JPG
IMG_1743.JPG
  7595   Tue Oct 23 09:37:33 2012 SteveUpdateSUS passive TT adjustment correction

Quote:

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.

Attachment 1: IMG_1745.JPG
IMG_1745.JPG
  7597   Tue Oct 23 16:18:03 2012 SteveUpdateVACRoughing pumps on for oil change

Leybold D30AQuote:

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.

Attachment 1: oilchange.jpg
oilchange.jpg
  7605   Wed Oct 24 09:15:12 2012 SteveUpdateVACvacuum rack 24V ps was current limited

Quote:

Quote:

Quote:

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.

 

Attachment 1: currentlimited24V.jpg
currentlimited24V.jpg
  7619   Thu Oct 25 08:04:45 2012 SteveUpdateSUSmy assesment of the folding mirror (passive tip-tilt) situation

Quote:

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.

 

Attachment 1: IMG_1748.JPG
IMG_1748.JPG
  7620   Thu Oct 25 09:32:17 2012 SteveOmnistructureIOOusing access connector

Quote:

Quote:

Quote:

Quote:

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.

Attachment 1: acclosing.jpg
acclosing.jpg
  7637   Mon Oct 29 09:33:42 2012 SteveUpdateSUSPRM & ETMY sus damping restored
  7645   Wed Oct 31 14:31:34 2012 SteveUpdatePEMhigh particle count

High particle count confirmed with #2 counter

Attachment 1: highparticlec.png
highparticlec.png
  7656   Thu Nov 1 17:37:00 2012 SteveUpdateGeneralbronze bushing for 40m vac

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.

Attachment 1: IMG_1764.JPG
IMG_1764.JPG
  7663   Fri Nov 2 16:09:14 2012 SteveUpdateGeneralOpen-sided mount - why

Quote:

Quote:

Quote:

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 )

ELOG V3.1.3-