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

RGA scan with maglev pumping speed at day 14 of the pump down.

The larger inserted box contains the tuning parameters of the SRS  200 amu RGA

APC Smart -UPS 2200   model: SUA2200RM2U   batteries were replaced by compatible RBC43, 8x  12V5A

We did the following:

1, closed V1, VM1,  annuloses: VASE, VASV, VABS, VAEV,  VAEE and VA6

2, stop rotation of Maglev-TP1, waited to decellerate and turned off power to it

3, closed V4,  stoped rotation of TP2, waited to decellerate and turned power off

4, opened VM3 to RGA that is still running

I will come in tomorrow 9-10am to restart pumping.

I failed to start Rana's favorit anciant desktop computer at the vac rack. He has to baby this old beast just a little bit more.

Vacuum status: Vac Normal was reached through Farfalla: Rga was switched back to IFO and and Annuloses are beeing pumped now.

V1 was closed for about a day and the pressure reached  ~2.8 mTorr in the IFO.  This leakrate plus outgassing is normal

The ref cavity 5000V was turned on.

The only thing that has to be done is to restart the RGA. I forgat to turn it off on Friday.

 As it turns out Steve is not crazy in this particular instance: the vacuum computer, linux3 , has some issues. I can login just fine, but trying to open a terminal makes the CPU rail and the RAM max out and eventually the machine freezes.

Under KDE, I can open a terminal OK as root, but if I then try a 'su controls', the same issue happens. Let's wait for Jamie to fix this.

I was lucky to notice that the nitrogen supply line to the vacuum valves was leaking. Closed ALL valves. Open supply line to atm. Fixed leak. 

This was done fast so the pumps did not have to be shut down. Pressurized supply line and open valves to

"Vac Normal" condition in the right sequence.

The foreline pressure of TP2 was 1.4 Torr this morning. This drypump worked well for ten months.

Recently rebuilt  drypump with new seal was swapped in.

This is how you do it: close  V1,  V4 and turn off TP2. Replace drypump and start up TP2

Set pump speed to 50 K rpm and open V4 to TP1 Note that the Maglev was not turned off  because V4 was closed off only 5-10 minutes.

Open V1 the status is Vac Normal.

TP2 is rotating at  50K rpm, current pick up 0.2A,  the temp is 26C and its foreline pressure 33 mTorr

The vacuum is ready for no AC power for 1 hr on Sunday morning at 10am

I did the follwing:

Closed V1,  stopped the rotation of TP-1 maglev, waited till it reached 0 Hz_ rpm  and  turned it's controller off.

Closed V4 and stopped TP-2 rotating

Closed all annuloses and VA6

Closed VM1 and opened VM3 This means the RGA is being pumped by TP3. RGA is running in background mode. V5 will close instantly as the AC will be turned off.

VAC STATUS:  IFO envelope and annulosses are not pumped.  P1  pressure will reach 5-6 mTorr by Sunday morning.

                                 The PSL output shutter will be closed by the interlock at 3 mTorr

Kiwamu will turn off Piezo Jena PZT power supplies and computers Saturday.

I will be here around 1pm Sunday to star pumping. I will need EPICs MEDM running by than.

State condition: Vac Normal,          CC1 ~8e-6 Torr

The IFO pressure peaked at  8.3 mTorr after 2days of not pumping.

 40m - pumpdown 71- maglev pumping speed - at day 276........all normal

 Steve, Yuta and Jamie

Jam nuts were checked and oplev servos were turned off. Sus summery is below with strain gauge values. Are the strain gauge values have any meaning when the PZT contorrels are off??????????????????

 The 4 hrs vent plot at 3 torr/min rate.

Nitrogen was used from 1e-6 torr to 35 torr  at intake pressure 14 PSI

The rest was filled with 5 cylinders of Instrument Grade Air at intake pressure 14 PSI

We can start opening chamber at 3 pm today

[Yuta, Koji, Jamie]

We went into ITMX chamber to inspect the situation there.  We looked for clipping and flipping at PR2, and found none, although we noticed that the beam at PR2 looks a little clipped.

We then went back into the BS chamber and took a closer look at the beam incident on PRM, and the situation with PR3.  The PRM incident beam looked a little clipped, which we expected from the PR2 observation.  But the beam looks well centered on PRM and PR3.  As best I could tell the beam is reflecting off the front surface of PR3, as expected.

Looking at the beam around MMT1 and PJ2 (the second PZT on BS), we could tell that the beam incident and reflected off of MMT1 looked round, where as the beam incident on PJ2 looked clipped.  Using my tallness super power I was able to reach into the IMC chamber and confirm that the beam going from MMT1 to MMT2 clips fairly badly on the edge of the Faraday.   Koji speculates that this is the result of a misalignment of the PSL output beam into the MC.  In any event, it's not clear how this would be the cause of our PRC woes.

We decided to close up for the night, and let Yuta work on aligning PRMI.  We need to figure out what the heck to do now.

We've been watching the input power reduce, from 18 mW initially when we first went in, to about 5mW now.  It seems to be leveling out now.  It's unclear what would have been causing it.  Drift of the input polarization?

Vacuum Normal State is reached in 9 hours.  CC1 =  2e-5 Torr

Aux dry pump #3 is still running.  The RGA is not pumped yet.

 I'm looking for some movement indicators of the vent-pump down events.

 I can not understand what really happened here with CC1 gauge or there was really a pressure glitch.

attachment 1,  pump down day 3 with 4th of July fireworks in the lab

attachment 2,  before and after vent in 9 days