The PSL shutter was closed. The beam path  blocked two places. High voltage power supplies to IOO and OMC PZT were checked to be off. Oplevs are off. 

The south arm green cavity was misaligned yesterday

We would like to keep the vent speed at 1 torr / min. I'm venting with N2 now up to 25 PSI. We have 3 cylinder  of instrument grade air inside the lab. Additional supply will arrive later. It can be as late as 1pm

The vent is still going on. At this moment the pressure inside of the chambers is about 630 Torr.

Koji and I have replaced the 2nd instrument grade compressed air cylinder by the 3rd cylinder around 9 pm.

So far the vent speed has been nicely kept at about 1 Torr / min.

The vent has been finished successfully in this morning.

_{The vent was finished successfully this morning.}

 Thanks to Kiwamu, Alberto and Koji

Bob and Steve closed BS chamber with the help of the manual Genie lift and the pump down started. The PSL shutter was closed and manual block was placed in the beam path. High voltage power supplies were checked to be off.

Pumping speed ~ 1 Torr/min was achieved at  1/8 of a turn opened roughing valve RV1

 We are at 370 Torr at 9 hrs of  pumping. RV1 is opened to ~ 3/8 turn orifice. We are using one roughing pump RP3  and butterfly valve is in place.

How to stop: 1, close RV1 by torque wheel  2, close V3 from MEDM screen  3, turn off RP3 roughing from MEDM screen  4, disconnect metal hose to oily pump

after butterfly valve. This KF-45 O-ring seal should be kept clean 5, place/close  45 mm cover blanks at the end of the hose and and on the 5" nipple.

How to start: 1, remove blanks from  hose and nipple 2, reconnect roughing pump hose to RV1 nipple  3, turn on PR3  4, open V3  5, open RV1 by wrench to ~3/8

6, fine tune RV1 opening to 1 Torr/min

ESSENTIAL: one operator has to be present when oilly roughing pump is connected to the vac. envelope

Kiwamu and Koji

The rough pumping was stopped at 230mmTorr. We are going to resume the pumping tomorrow morning.

• RV1 was closed with torque wheel.
• V3 was closed from MEDM
• RP3 wss stopped from MEDM
• The quick coupling to RP3 was disconnected.

I resumed the pumping down. It started from 9:55 am.

I stopped the pumping at 14:50 pm because I was going back home. I did the same procedure as Koji wrote down (see here).

The P1 pressure reached 32 Torr.

Koji will take over the pumping shift tonight. 

I resumed the pumping from 19:00.

Now the valve RV1 is full open. But the pumping is really slow as we are using only one RP.

After 3hrs of pumping, P1 reached 1.2mmtorr but still we need 2hrs of pumping...

I stopped pumping at 22:30.

I resumed the pumping today. Now the pressure is 0.48 torr. The pump was stopped.

 3 days pump down #69 completed. Thanks to Koji  and Kiwamu  who did more roughing on Saturday and Sunday.

Blocked PSL output beam  into IFO

Checked: HV at IOO & OMC are off, jam nuts in position,

Closed V1 and VM3, opened VV1 to N2 regulator

We are venting at 1 Torr/min rate

(Koji, Yuta, Kiwamu)

Now the pressure at P1 is 740 torr, which is close to the atmospheric pressure of 760 torr.

We changed the air cylinder twice in this evening, and the last cylinder ran out at about 23:00 pm.

We left it as it is. Steve is going to make a final touch for it tomorrow morning.

(Steve, Koji, Joe, Kiwamu, Yuta)

Background:
 The vent was started on Monday, and finished on Tuesday.
 We were to open the doors on Tuesday, but we couldn't because the vertex crane got out of order.
 Now the crane was fixed, and so we opened the doors today.

What we did:
 We opened the north side of the BS chamber and the west side of the ITMX chamber.
 Now, the light doors are put instead.

(Koji, Kiwamu, Yuta)

Lots of progress for the optics placement in the vacuum chamber.
We are ready to go to the next step: open the access connector between IMC and OMC. 

Background:

The actual work in the vacuum chamber started.
The first goal of the vent is to get the green beam coming out from the chambers to the PSL table.

What we did:

1. Inspection of the tip-tilt suspension

The alignments of the TTs were inspected. We had five TTs having been sitting on the table in Bob's clean room.
Prior to their installation we checked the alignments of those because they sometimes showed large hysteresis mainly in the pitch directions.

If a TT has the hysteresis, the pitch position doesn't come back to the previous position. This may cause an issue of the interferometer operation.

- SN001, SN003, SN005 looked well aligned and show no hysteresis.

- The alignment of SN002 was not so good (theta ~ 0.004 rad ) compared to those three, but no hysteresis, we think this guy is still acceptable for the installation.

- SN004 had an apparent hysteresis. This guy doesn't come back to the previous place, being applied a touch. We have to fix this at some point.

2. Work in the ITMX chamber

Now all of the optic in this chamber was installed in the approximate place.

- Installed POX/POP steering mirrors.

- TT(SN003) was placed.

- The two steering optics for ITMX OPLEV were placed at the designed positions.

3. Work in the BS chamber

Installed 2 TTs to the BS chamber.
- SR3: TT(SN001)
- PR3: TT(SN005)

After the alignment of the green steering mirrors, we confirmed
the green beam is successfully hitting the west wall of the OMC chamber.

Those TTs are approximately aligned using the weakly reflected green beams.

Next work:

- Open the access connector

- Place another periscope and two steering mirrors for green

- Damping of the suspended optics

- Resurrect MC and its stable lock

- Remove MCT pickoff path

- Align optics in the main path

- Recycled Michelson lock

Kiwamu, Koji, Yutah, Rana, Jan and Steve

We removed the west access connector this afternoon.

YES ! We got the green light coming out from the OMC chamber to the PSL table !

 (Koji, Kiwamu, Yuta)

Background

As a result of the work in the chambers, the green beam reached the OMC chamber yesterday.
Today's mission was to let the green beam coming out from the chambers to the PSL table.

What we did:
1. Installed the last three steering mirrors.
  The mirrors were 532 HR mirror with AR and 1deg wedge (CVI Y2-LW-1-2050-UV-45-P/AR).
  Two of them are placed to the MC chamber. Another one was to the OMC chamber

During putting the mirrors to the MC chamber, we found that a cable tower was sitting on a position exactly where we wanted to put one of the mirrors.

So we moved the tower to the very south west corner. 

2. Installed a periscope to the MC chamber

The function of this periscope is to lower the beam height of the green light which is risen up by another periscope in the BS chamber.

We aligned it to the green beam, so that the beam hits the center of the mirrors on the periscope.  

3. Aligned the optics

We aligned the green mirrors so that we can let the green beam go out from the chamber.

Actually the inside of the OMC chamber didn't look like the same as that of our optical layout.

For example there is unknown base plate, which apparently disturbs the location of our last steering mirror.

Therefore we had to change the designed position of the steering mirror.

Now the mirror is sitting near the designed position (~ 1/2 inch off), but it's fine because it doesn't clip any 1064 beam.

 
Result:

The green beam is now hitting the north wall of the PSL table.

Notes:

The green beam looks having some fringes, it may be caused by a multiple reflection from a TT when the green beam goes through it. We are going to check it. 

Next work:

- Damping of the suspended optics

- Resurrect MC and its stable lock

- Remove MCT pickoff path

- Align optics in the main path

- Recycled Michelson lock

[Steve, Jenne, Suresh, Koji]

The remaining test mass chambers have been opened, and have light doors in place.  Now we can do all of the rest of the IFO alignment, and then (hopefully) button up before the New Year.

This condition is created when we run out of nitrogen that holds the valves in set positions. The Maglev and other turbos are still running in this configuration so one has to pay attention that the foreline valves are open.

Reset  error message on vacuum screen and opened V4 & V5 at 3pm today.

Slow pumpdown of rebuilt IFO-mark4 started at 3pm today.

We are at 680Torr at this minute with 1.5 Torr/min speed.

 [Jenne and Kiwamu]

 We wiped all the test masses with isopropyl alcohol.

They became apparently much cleaner.

(how to)

 At first we prepared the following stuff:

  * syringe

  * isopropyl alcohol 

  * lens papers

  * cleaned scissors

  Then we cut the lens papers into the half by the scissors such that the long side can remain.

This is because that the SOSs have relatively narrow spaces at their optic surfaces for putting a piece of paper. 

   We did vertical and horizontal wiping using the lens paper and appropriate amount of isopropyl alcohol.

Each wiping (vertical and horizontal) requires two or three times trials to appropriately remove dusts.

Amount of isopropyl:

   * vertical 15 [ul]

   * horizontal 10 [ul]

In addition to this, we also used the ionizer gun for blowing big dusts and fiber away from the surface.

(surface inspection)

   Before wiping them, all the test masses had small dusts uniformly distributed on the HR surfaces.

Especially ETMX was quite dirty, many small spots (dusts) were found when we shined the surface with the fiber illuminator.

ETMY was not so bad, only a couple of small dusts were at around the center.  ITMX/Y had several dusts, they were not as dirty as ETMX, but not cleaner than ETMY.

   After we wiped them,  we confirmed no obvious dusts were around the centers of the optics. They looked pretty good !

[Jenne Kiwamu Joe Osamu Steve Koji]

Yesterday (21st), we closed the BSC and the four testmass chambers.

We splitted the team into three.

- Wiping team (Jenne/Kiwamu)
- Suspension team (Osamu/Koji)
- Door closing team (Joe/Steve)

While the wiping team was working, the suspension team prepared the next suspension.
Once the mirror was wiped, the suspension team restored that suspension at the position of the markings on the table.

After the wipe of the first mirror, the wiping team got experienced and they were the fastest among the teams.
So the wiping team worked as the second suspension team when necessary.

All of us became the closing team after the last suspension has been restored.

We checked that we still have the Michelson fringes and the oplev pointings.

In total, the work was very efficient such that we only took four hours for the entire process.

We left the suspension marking on the optical tables because they are quite useful.

We have reached 200 Torr at 12 hours of slow pumping speed. Kiwamu stopped the pumping for 11 hrs last night .and I restarted it this morning.

Now RV1 is fully open with butterfly valve in place  and the second roughing  pump RP3 was just turned on.

How to stop pumping:

1,  close RV1 manual valve with torque wheel

2, close V3

3, turn off roughing pumps RP1 & RP3

4, disconnect metal hose connection to butterfly valve

I stopped the pumping at 9:30 pm. Now we are at 29 torr.

The pump down continued this morning by the removal of the butterfly valve. Two roughing pumps were used to reach 500 mTorr

The Maglev monitoring MEDM screen "Rotating" indicator is not working. It is on all times. Please look at Maglev controller monitor for real information.

Pump down is completed.           

Configuration: vacuum normal after 86 days at atm               CC1 = 1e-5 Torr                  

                      IFO is hungry for light (and maybe some goulash with a little paprikash too)

Joe updated the rga procedure in the wiki and we turned on the filament. It will take a few days to reach thermal equilibrium.

TP2 dry fore pump was replaced at 910mTorr

The RGA scan is normal at day 52 of this pump down.

Light power BS 1064nm ~25mW, ETMX 532nm ~5mW

We have one single O-ring on the 40m vacuum envelope. It is on the OOC west side, facing the AP table. This O-ring has to be protected from the force of this

door. There should be 3 shims  ~120 degrees apart to carry the full load, so it is not the O-ring that is getting squashed.

This morning I found only one of these shims in place.

Dry fore pump of TP3 replaced by brand new Varian SH-110  at  1.1 Torr_75,208 hrs

The annuloses were closed off for 25 minutes. We are back to VACUUM NORMAL mode.

The TP3 fore line pressure dropped to 44 mTorr at 25 minutes in operation.......9.4mTorr at day 2 with full annulos load

Dec 21, 2010 we pumped down the MARK4 rebuilt 40m-IFO and the malev has been pumping on it since than

We have cleaned, baked, rga scaned traps for vacuum. Thorlabs LB1 on 1" OD ss posts and forks. The effective surface area is 43 x 18 mm of stacked razors.

Seven pieces are mounted on New Focus #9962  1" OD SS vented-  pedestrals to 5.5" center height and 5 pieces to 4.875"

Both arms locked easely around 1V transmited.  We should recenter oplevs.

The vacuum system is coming up to atm. The vent was started with slow N2 flow. The PSL output is blocked 2 places on the table.

An important rule during the in-vac work :

   Do not change the incident axis of the X and Y green beams.

Because of the air flows and unusual pressure in the chambers, the DC alignment of the suspensions become less reliable in terms of the beam pointing reference.

The green beams will be considered as references during the vent.

P1 at 750 Torr,  Vent valve VV1 is left open to atm. It will reach equilibrium in an hour. The PSL power is not turned down yet. The beam path is blocked at two places inside the enclosure.

The low power 20 mW  input  MC can be locked tonight.

Next day's - Thursday notes:

We  reached 760 Torr of atm in 8 hrs at  1.7 Torr/ min with 5 cylinders of  instrument grade air.

Used 500 PSI of nitrogen to get to 20 Torr at first.  This flow  and the first cylinder of N2  has to be slower next time.

We did the following:

1, oplevs were centered on locked caveties 2 days ago

2, just before vent we rechecked arms  pointing, they wre still locking

3,eloged strain gages  and turned HVs off at PZT-steering   at 1Y3 rack and OMC-PZT ps at 1X2 aux rack. They were actually off.

4,,checked jam nuts 6 places x 3

5, turned oplev servos off

6, eloged SUS summery page

7, checked particle counts at ITMY: 1 micron 300,  0.5 micron 3K,  0.3 micron  30K particles / cft-min. All three cranes were wiped 2 days ago.

8, blocked laser into IFO: main 1064 in 1.25W were blocked by manual 2 blocks on PSL table. The PSL output shutter was left open to be triggered by interlock  at P1 3 mTorr. It did!

    Aux NPRO-AP and green light  input at both ends were blocked.

The RGA region is beeing monitored during the vent. This will tell us how clean the RGA itself is.

Jenne found a big scratch on the north vac door of ITMY. Fortunately it does not reach the inner annulos 0 -ring seal.

This is precisely what we have to avoid to preserve our vacuum system!

For some reason the workstation at the vac rack was off and unplugged. Nicole and I plugged its power back in to the EX rack.

I turned it on and it booted up fine; its not dead. To get it on to the network I just made the conversion from 131.215 to 192.168 that Joe had done on all the other computers several months ago.

Now it is showing the Vacuum overview screen correctly again and so Steve no longer has to monopolize one of the Martian laptops over there.

Cranes are  checked and they are ready for lifting. At the east end will use the manual Genei-lift to put door on.

[Steve, Bob, Jamie, Kiwamu, Valera, Jenne]

The access connector is now in place, in preparation for pump-down.  Tomorrow (hopefully) we will do all the other doors.

Jamie is modeling our next generation  in-vac & clean room bonny suit that Jenne and myself already tested.

It is quite bearable with our traditional cleanroom beret-bouffant cap. Please use these in the future.

This will help to avoid the farther degradation of somewhat dusty 40m vac envelope.

It is the required dress code to enter the clean assembly room in the 40m.

 We have small, med, large and x-large in stock. I'm getting larger sizes.

It will not allow certain people to climb inside the vacuum chamber in dirty pants.

The RGA back ground at day 29 of this vent.

Steve and Jamie:  After Jamie checks the ITM free swingings, please put on the ITM heavy doors and start the pump!  For real this time!!! Yeah!

Jamie and Steve

We closed ITMX and ITMY chambers and started pumping around 11am

What we did before:

1, turned off AC power  to PZT Jena HV ps

2, checked jam nut positions

3, cheched  single o-ring shims

4, closed psl out shutter

 We are at 30 Torr of 7 hours of pumping with 2 roughing pumps.

Kiwamu will take over the rest of the roughing today. He will keep an eye on  the pumping speed to be  ~1-2 Torr/min  and open up the manual RV1 valve if needed.

The present status is #3023 of  "chamber open to vacuum open" mode and waiting the P1 pressure to drop to 500 mTorr

He will do the following to stop pumping at P1 = 500 mTorr

1, close V3

2, close RV1 with torque wheel

3, turn off PR1 & 3

4, disconnect metal hose between RV1 and PR3

 I will start the Maglev tomorrow morning.

I stopped puming at 9:30 PM and the pressure in P1 is at 450 mtorr.

I followed exactly he procedure that Steve noted on his elog entry.

Here is a plot of the histroy of our pumping today.

Vacuum status:  " vacuum normal"   CC1 pressure 5e-5 Torr

Slow roughing through butterfly valve took 11 hours at 1-2 Torr/min speed.  We had a leak at the metal hose connecting o-ring  that became visible  at 200 Torr.

The vacuum envelope pressure rose to 500 mTorr from 450 mTorr  This is 50 mTorr leak plus outgassing over 11 hrs  over night stop =  5  mTorr /  hr

Atm2, Maglev pumpdown details. P2 and P3  are in the foreline of the Maglev. The pressure peaks at 4 Torr beacause the 3 drypumps have  little pumpimg speed at this range.

            External fan is turned on during this one hour period to prevent  Maglev turbo from overheating.

            Same things are  happenning with the two small TP2 and TP3 pumps under load. Their foreline pressure peak at 1 Torr.  They slow down to 45 K RPM from 50K RPM  and warm up to 36-39 C

Precondition: 36 days at atm