As preparation for the upcoming planned power outage we turned turbos, RGA off and closed valves.

IFO chamber is not pumped now. Small leaks and out gassing will push the pressure up slowly. At 3 mTorr of P1 the PSL output shutter

will be closed by the interlock.

It is OK to use light in the IFO up to this point.

The Vac pressure measured at P1 is at 2.5mTorr.  I expect we'll hit 3mTorr sometime this afternoon, at which point (according to Steve) the interlock will shut the shutter, and we won't have light in the IFO.  Anything which needs to happen with light in the IFO before Monday needs to happen fairly soon.

Morning condition: vacuum rack power is still off, no MEDM screen reading.....meaning unknown vacuum pressure.We closed PSL shutter immediately.

Joe restored c1iscepis and Jenne powered up the vac-rack UPS. Now the rest of the vac-rack power were restored from starting at the top to bottom.

P1 was reading 15 mTorr.  We restarted pumps and  set vacuum valve positions. V1 opening required Rob's recipe of elog # 1863 to defeat interlock that

has a non communicating gauge: PTP1

CC1 pressure just reached 1e-6 Torr at VAC NORMAL configuration.

Kiwamu and Steve have started venting the 40m vacuum envelope.

Preparation:

centered oplevs at resonating cavities,

ITM references were set by green pointer from the ends by Koji,

closed  PSL shutter and placed manual block into beam path,

checked  jamnuts in locked positions on bellows,

turned  HV off at PZT-Jena "steering mirror" power supply and OMC HV ps

checked  particle counts,

switched oplev servos off,

set up N2 cylinder to start vent from 1e-6 Torr to 25 Torr,

have ~ 6 cylinders of instrument grade compressed air to bring envelope from 25 Torr to 760 Torr

All three cranes were wiped off today.

 Our vacuum was not pumped for 4 days. The computers were not up when we started pumping again. The manual reading on P1 was 15 mTorr.

This means that our outgassing plus leakrate is  ~3.8 mTorr /day 

3-5 mTorr / day is normal

The vent has been finished.

Now the pressure inside the chamber is 760 torr, and it's getting equilibrium with the atmospheric pressure.

Therefore we are ready and can open the door of the chamber tomorrow.

 Kiwamu has completed the vent.

There is a planned power outage tomorrow, Saturday from 7am till midnight.

I vented all annulies and switched to ALL OFF configuration. The small region of the RGA is still under vacuum.

The vac-rack: gauges, c1vac1 and UPS turned off.

 Vac- rack is powered back up.  UPS first, than all other power switches from top to bottom of the rack, except Maglev

Manually started one by one TP2 and TP3  to accelerate to 50 KRPM

Brought up vac.control screen on lap-top at /cvs/cds/caltech/medm/c0/ve/VacControl_BAK.adl

V5 and VM3 were opened so TP3 can pump on the RGA

V4 was opened so TP2 can pump on the Maglev-TP1. The Maglev power was  turned on and started acceleration.

The vac control screen positions indicators were checked for true position and annulies vent valves were opened.

RGA manual on/off switch was turned at the top of the RGA-head. Ubuntu copmuter was started at cc4 1.1e-6 Torr

The RGA communication was started with:  ssh c0rga from control room

The rga-script was started ./RGAset.py     This script turns on the filament, rs-232 and scan parameters etc

Vac -configuration: IFO-P1 at atm, RGA is pumped and running in background mode, all annulos at atm

RGA scan of rga-region only at day 18   This is the back ground of the rga with some calibration gas.

Steve and Koji

We aligned the peeping mirrors to look at the surface of the ITMs.
They had been misligned as we move the positions of the ITMs, but now they are fine.

[Jenne, Kiwamu, and Steve via phone]

Around 9:30pm, Kiwamu and I came back from dinner, and were getting ready to begin the beam scan measurements.  I noticed that one of the vacuum pumps was being very loud.  Kiwamu noted that it is the fore pump for TP3's turbo, which he and Steve replaced in January (elog 2538).  We had not noticed these noises before leaving for dinner, around 8pm.

We called Steve at home, and he could hear the noise through the phone. He said that even though it was really loud, since it was reading 3.3mTorr (on the display of the controller, in the vacuum rack just above head-height) which is close to the nominal value, it should be fine to leave.  He will check it out in the morning.  If it had been reading at or above ~1Torr, that's indicative of it being really bad, and we would have needed to shut it off.

For future reference, in case we need to turn it off, Steve said to use the following procedure:

1. Close VM3, to isolate the RGA, which is what this pump is currently (while we're at atmosphere) pumping on.  I don't know if there are other things which would need to be shut at this stage, if we were at vacuum nominal.

2. Close VM5, which is right in front of TP3, so TP3's pump is just pumping on itself.

3. Push the "Stop" button on the Turbo controller for TP3, in the vacuum rack, about waist level.  Turning off the turbo will also turn off the fore pump.

UPDATE, 1am: The controller in the rack is reading 3.1mTorr, so the pump, while still noisy, still seems to be working.

 The foreline pressure of TP3 is 2.9 mTorr  The drypump is loosing it's bearing and it is very noisy.

V3, V5 closed and TP3 small turbo controller off. This turned off the noisy forepump that has to be replaced.

RGA is running at cc4 2e-6 Torr

The RGA was turned off at cc4 1e-5 Torr

Bob replaced the tipseal in an other drypump and I swapped it in. TP3 turbo is running again, it's foreline pressure is 40 mTorr. The RGA is still off

We started a vacuum work in this morning. And still it's going on.

Although the last night the green team replaced a steering mirror by an 80% reflector on the PLS table, the beam axis to the MC looks fine.

The MC refl beam successfully goes into the MCrefl PD, and we can see the MC flashing as usual.

We started measuring the distance of the optics inside the vacuum chamber, found the distance from MC3 to MMT1(curved mirror) is ~13cm shorter than the design.

We moved the positions of the flat mirror after the Faraday and the MMT1, but could not track the beam very well because we did not completely lock the MC.

Now we are trying to get the lock of the MC by steering the MC mirrors.

P.S.

Kevin suceeded in locking it !!

 Hey guys,

I just finished redoing the calc based on the measurements that happened last week.  Using the average of the Vert and Horz measurements in Kevin's elog 2986, I find that we need to make the MMT telescope ~8cm longer.  So, can you please place the flat mirror after the Faraday in the same place as the drawing, but move the MMT1 79mm farther away from that flat mirror?  Looking at the table layouts that Koji has on the wiki, this should still (barely) fit.

New distances:

d2a = 884.0mm (no change) ------  MC3 to Flat after Faraday

d2b = 1123.2mm (move MMT1 farther toward center of BS table)  -------- Flat after Faraday (SM1) to MMT1

d3 = 1955.0mm (result of moving MMT1)  ---------  MMT1 to MMT2

d4a = 1007.9mm (no chnage)        ----------- MMT2 to SM2

d4b = 495.6mm (no change) ------------ SM2 to PRM

I just got off the phone with Alberto and Kiwamu, and I'm going to try to recalculate things based on their measurements of the distances between MC3 and SM1.  It sounds like the CAD drawings we have aren't totally correct.    I know that when we opened doors just before Christmas we measured the distances between the BS table and the ITM tables, but I don't think we measured the distance between the IOO table and the BS table.  Hopefully we can fit everything in our chambers.....

Some unused optics in the BS chamber were removed. 

After that the beam splitter has been drag wiped. 

So now the BS chamber is waiting for the installation of  the other core optics i.e. PRM, SRM and Tip-Tilts. 

-- removing of unused optics

      There were some unused optics, mainly 1.5 inch optics which had been used for the oplevs in the chamber. 

Kathaine, Shamila (Team Magnet) and Kiwamu took those optics out from the chamber.

And then we carefully wrapped each of them by aluminum foils and put them in some clear boxes.

In fact, before wrapping them, we gently attached lens papers on their HR surfaces such that aluminum foils can not damage it.

Now there are only three 1.5 inch optics in the chamber, and they are supposed to be used for the oplevs.

We didn't remove any of the 2 inch optics and the PZT mirrors because they are still going to be used.

These are the pictures of the BS chamber after we cleaned up them. 

-- wiping of the BS

        Rana and Kiwamu drag wiped the HR surface of the BS by using lens paper with the solvents.

The below is the procedure we did. You can find some details about the wiping technique for suspended optics in this entry.

In this time we could wipe the beam splitter without removing the front earthquake stops because the beam splitter was brought close enough to us. 

(1). put some blocks attaching the edge of the bottom plate of the tower in order to record the original position.

(2).  locked the beam splitter to the frame by screwing the earthquake stops.

(3). made sure if it is really locked by seeing the output signal of the OSEMs in dataviewer. If it's locked successfully, the resonant frequency gets higher and the Q-value gets lower.

(3).  moved the BS tower close to the door in order to reach the beam splitter easily.

(4). inspected the surface by using a fiber light. There were about 10 bright spots on the HR surface.

(5). wiped the surface three times by using the lens paper with Aceton.

(6). wiped it several times with Isopropyl.

(7). inspected the surface again, found there were no big bright spots near the center. Thumbed up 

(8). put the tower back to the original place and released the beam splitter from the earthquake stops.

[Jenne,  Kiwamu, Steve, Sharmila, Katherine, Joe]

We finished bolting the door on the new ITMX (old ITMY) and putting the access connector section back into place.  We finished with torquing all the bolts to 40 foot-pounds.

The folding crane was fixed and tested this morning by the NNN rigging company. Pictures will be posted by Steve in the morning.

Afterwards, the ITM-east door was installed, jam-nuts checked. No high voltage was on for the in-vac PZTs.

The annulus spaces were roughed down to 350mTorr by Roughing Pump RP1. For this operation, we removed the low flow valve from the RP1 line.

After the spaces came down to ~400 mTorr, we closed their individual valves.

Warning: The VABSSC1 and VABSSC0 valves are incorrect and misleadingly drawn on the Vacuum overview screen.

We then:

1. Closed V6 (valve between RP1 and the annulus line).
2. Turned off RP1 from the MEDM screen.
3. Installed the soft -starting butterfly valve.
4. Turned on RP1.
5. Opened V3.
6. Closed VV1 (at the last minute - this is a vent valve and must be checked before each pumpdown)
7. and pumpdown was started with a 3/4 turn opening of manual valve RV1.

Our idea is to have a much slower pumpdown this time than the last time when we had a hurricane kick up the dust. Looks like it worked, but next time we should do only 1/2 turn.

The pumpdown started at 4 PM (2300 UTC). At 10 PM, we (Jenne, Jan, and I) opened up the RV1 valve to full open. That's the second inflection point in the plot.

As per Steve's instructions, at 12:43 AM, I used the following steps to stop the pumpdown until the morning:

1. Close RV1 using the 'steering-wheel' wrench.
2. Close V3.
3. Turn OFF RP1.
4. Disconnect RP1 hose at the plastic disconnect attached to the slow-start throttle valve.

 Atm 2 is showing the butterfly valve that closes down down the orifice at higher pressure to slow down the pumping speed.

 See elog entry #2573

Slow pump down _pd68 has reached the vacuum normal state.  CC4_Rga region is pumped now. The RGA is still off.

Precondition to this pump down:                                                                                                                                                                                                                                                           129 days at atm,                                                                                                                                                                                                                                                                                         ITMs replaced. MMT, oplev and other components were removed from BSC, ITMCs. New MMT mirrors are in.                                                                                                             IOO_access_connector was out. The end chambers were not opened.

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.