The pressure is CC1 3e-4 Torr at 8 hours of pumping. Status: vacuum normal
The IFO is ready for light
It took 15 days to reach 1e-5 Torr
The RGA was turned on yesterday. The rga scan plotting was not working. Den wrote a Python script to log and plot because the Mathlab had trouble receiving data from our old c0raga.
It turned out that the Joe's log&plot system was working today. Thanks Den and Joe.
Here is the first rga scan.
The 40m vacuum envelope is at atm It took 4.5 hours at ~3 Torr/min speed. Atm1
What I did:
Turned PZT voltages off: 84.1V at OMC-rack location
- 99V at 1Y3 location as PZT_pitch,
56.6V KEPCO at 1Y3 location as PZT_yaw
Took screen shuts of SUS_SUMMARY, yesterday, Atm3
Turned off OPLEV _SERVOs, today , Atm2
Closed PSL_SHUTTER and green shutters at the ends
Set vacuum valves for vent position and opened VM2 for the RGA
Koji, Manasa, Jenne, Jamie, Bob and Steve
Access connector removed this morning and work has began in the IOO chamber. BE WARE OF ANTS !
The COVAC_MONITOR.adl was changed. Ion pump labeled as disconnected means: ion pump controller power turned off and ion pump gate valve control connection disconnected.
RP2 roughing pump labeled disconnected means: hardware disconnected.
The actual operational, valve control screen has not been changed yet.
Reminder: I will be on vacation next week. We would have to put the access connector in tonight if I'm pumping down Friday, tomorrow.
RGA background with VM2 open to Maglev at day 37
Note: The PAN gauge of the annulos is at atm. Please do not vent this 200 ft long annulos line when you venting the annulos of a chamber. The chamber annulos should be closed off to this long 2" OD. pipe before you vent the annulos of a chamber.
CP Stat 100 sheet-covers were replaced by clean ones on open chambers BS, ITMX, ITMY and ETMY this morning.
Try to fold the sheets such way that the clean side is facing each other, so they do not accumulate dust.
[Steve, Yuta, Koji]
The ETMX heavy door was removed.
[Steve, Manasa, Jenne, Sendhil, Evan, Yuta]
We put heavy doors on ITMX/ITMY/BS chamber and started pumping down from annulus.
What we did:
1. Replaced POP55 with AS55 back, because it was not broken.
2. Centered on AS55, REFL55, REFL11, POPDC PD.
3. Tried to lock PRMI, but I couldn't lock even MI stably for more than 1 min. I believe this is because it was noisy this morning. But I checked again that REFL/POP/AS beams are coming out without clipping and we have some error signals.
4. Noticed AS beam has less range in left (on AS camera), so we tweaked OM4 a little to make more room.
6. Took pictures inside ITMX and BS chambers
7. Put heavy doors on ITMX/ITMY/BS chambers.
8. Started pumping down annulus.
9. Recentered IPANG/IPPOS and oplevs on their QPDs.
POP, REFL, AS:
We are pumping down with RP1 & RP3 oily roughing pumps at 3 Torr/min speed. The butterfly valve was just removed.
The PSL shutter is open to vacuum at ~100 mW 1064 nm. The inter lock should close it at ~5 mTorr.
Rana will shut down pumping tonight.
He will close V3 from screen, close RV1 valve with torque wheel, turn off roughing pumps and disconnect hose between RV1 and roughing pumps.
I will restart pumping early morning tomorrow.
[Rana, Yuta, Koji]
21:05 at the pressure of 10torr
V3 closed. RV1 manually closed. RPs were turned off. And the bellows between RV1 and the rughing pumps are disconnected.
Pump down is restarted after 10.5 hrs stop overnight.
IFO P1 pressure is 1 mTorr. It is ready for high power light.
The Maglev took over the pumping at 500 mTorr
All normal, IFO pressure 1.5e-5 Torr
RGA is pumped by TP-3 in back ground mode.
Atm1, RGA background scan with TP3 pumping at day 7
Atm2, IFO CC1 = 1.1e-5 Torr at day 8
Vacuum valve VM3 closed and VM2 opened, it switched the RGA to IFO scanning mode. CC4 = 3.5e-6 Torr
TP3 is pumping on the annuloses, their pressures are 1-3 mTorr
Vacuum condition reached the state of Vacuum Normal. The MEDM screen "Current State" channel does not work because we disconnected some valves after the VME swap CAOS
Note: TP1 Maglev performance on Atm2 CC4 = 4e-9 Torr when VM2 valve was open
TP3 turbo pump's dry-foreline pump was replaced.
How to do it:
The pump should be replaced when it's performance <1.0 - 1.3 Torr
Set up valve configuration as shown at Atm1: close in this order VAEE, VASV, VABS, VASV, VASE, VA6 and V5,
Turn TP3 off at it's controller in the rack. Wait till is stops, so you can read 760 Torr at TP3 foreline gauge
Disconnect intake, exhaust vacuum seals and replace pump. Reconnect vacuum fitting and start it up.
Confirm operational details on the front of the controller: 50 K_RPM, 0.2A and <100 mTorr
Reset valves in reverse order
PS: the average life of the tip seal on the Varian SSH-110 dry-pump is about 1 year
This pump " ser LP1007L556 " seal made new record of 668 days: thanks to Bob Taylor who is replacing these seals
Pumpdown 75 - Maglev - day 12
Precondition: 66 days at atm, installed TIP-TILTs with coils that replaced PZT-Jena input steering
Optical quality 6.5" OD window specs and quotes for vacuum view ports and optical table enclosure are on the 40m wiki_ Aux Optics page.
We have just received a very good quote #2 from Cascade Optical.
Vacuum normal condition at pumdown day 100
Pumpdown 75, vacuum normal condition at day 144
Thanks for the good preparation. IFO pressure P1=20 Torr
The 40m IFO has reached atmospher in 5 hours. It is ready to open chamber condition. The RGA is pumped with the maglev.
P1 pirani gauge is contact dependent as you see it on the linear plot It will be replaced during this vent.
The venting speed was 2-4 Torr / min
Atm2 shows how the BS is sensing the venting air cylinder changes.
The 4th cylinder of instrument grade air bump is overlapping with our janitor working at the BS chamber.
We will open the BS and ITMY doors first thing tomorrow morning. I plan to try to be in around 9 am. The first order of business will be to flip the folding mirrors that are not currently flipped (SR2, SR3, PR3).
Jenne, Annalisa & Steve
Manasa, Eric, Evan, Koji and Steve,
Access connector removed in order to complete alignment. Light aluminum with acetate windows AC installed.
Prior to the access connector removal, Manasa and I aligned the IFO mirrors.
The arms were locked and aligned by ASS.
We have been using Air Liquide Instrument Grade Air for venting the 40m vacuum envelope. It is no longer available.
The replacement is Alphagas 1, total hydrocarbon <0.1% ppm
LINK TO Alphagaz
Air Liquide > ALPHAGAZ™ Specifications
Because each analytical application is sensitive to critical impurities that can affect your results, tests in our research center and analyzer manufacturers' studies confirm that the main impurities are moisture, oxygen and hydrocarbons.
Based on these critical impurities, Air Liquide has developed ALPHAGAZ™ brand with a Maximum Impurity Level (H2O, O2, CnHm).
RGA background at day 12 of this vent . The maglev is pumping on the rga through VM2
The pumpdown has started at 8:38am
Manasa was here to confirm good alignment of the IFO
Inner jam nuts of AC bellow were torqued to 45 ft/lbs and door nuts were check on opened chambers.
Annulos were roughed down to 500 mTorr
Oplev servos turned off, PSL and green shutters closed before pumpdown started
IFO P1=1mT PSL shutter is opened
Cold cathode gauge CC1 -h (horizontal) just coming on 9.2e-5 Torr
P2 is the fore line pressure of the maglev. One can see the 4 Torr load during switching over to turbo pumping.
CC4 5e-9 Torr is the performance of the maglev pumping on the RGA only.
The annuloses are not pumped now. They are closed off to see how much outgassing plus leak they have.
Configuration: vacuum normal, annuloses not pumped
Precondition: 14 days at atm, IOO chamber north door was taken off as a new entrance, the ETMX chamber was not opened.
What is new in the vacuum system: new P1 pirani gauge, gold plated clean allen wrench and ..........what else was dropped?
Note: the wireless laptop did not fail once all day yesterday. I want to give credit to the person who is responsible for this.
TP2's fore line - dry pump replaced at performance level 600 mTorr after 10,377 hrs of continuous operation.
Where are the foreline pressure gauges? These values are not on the vac.medm screen.
The new tip seal dry pump lowered the small turbo foreline pressure 10x
TP2fl after 2 day of pumping 65mTorr
1, Vacuum envelope grounds must be connected all times! After door removal reconnect both cables immediately.
2, The crane folding had a new issue of getting cut as picture shows.
3, Too much oplev light is scattered. This picture was taken just before we put on the heavy door.
4, We were unprepared to hold the smaller side chamber door 29" od of the IOC
5, Silicon bronze 1/2-13 nuts for chamber doors will be replaced. They are not smooth turning.
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.
Based on the facts above I reconnected VC1 and VC2 valves. State recognition is working. Ion pumps are turned off and their gate valves are disabled.
We learned that even with closed off gate valves while at atmosphere ion pumps outgass hydrocarbons at 1e-6 Torr level. We have not used them for this reason in the passed 9 rears.
I need help with implementing V1 interlock triggered by Maglev failure signal and-or P2 pressure.
MEDM screen agrees with vacuum rack signs.
Fred Goldbar of KoneCranes will come 7:30am Wednesday, September 4 to look at this issue.
It is changed to Thursday morning.
Valve configuration: Vacuum Normal
[Fred Goldbar, Mike Gerfen, Dennis Coyne and Steve]
We inspected the hinge, 1.25" cross pin and I-beams. It is hard to explain what is causing the folding I-beam corner to jam against the main I-beam.
To limit the motion of the folding I-beam cross pin bushing will be added. This will take a week to complete.
KoneCrane contact John McDaniel (562) 903 - 1371,
Wednesday, September 18, folding I-beam will be removed. KoneCrane will start working at 7:30am and they should be out by 12:30pm
Friday, September 20, reinstalling machined hinge on the I-beam. Same timing schedule as Wednesday.
TP3 foreline's dry pump is getting noisier and noisier. Turbo TP3 is pumping on the annulos. The foreline pressure is 7.2 mTorr and it is not degrading. It was swapped in March 5, 2013
The seal is very good, but the bearing is dying.
The drypump is replaced at 95,781 hrs on TP3 controller time. The foreline pressure is 30 mTorr and dropping.
It is 13 mTorr after 17 hours of pumping.
Finally we reached 1.0e-5 Torr, cc1 (h) at day 41. There must be a leak or cold cathode gauge is not reading correctly. The gauge is new. It should not take this long.
All chamber annulos pressures are normal.
The folding beam removed as shown. Two man supporting it while I hammering it out. Pin was dry and it gulled into supporting hinges.
The rotating hinge will be machined and bushing will be added with Zerk fitting or similar. This will allow lubrication in the future.
see elog #9111
Atm1, The folding arm is back on with 0.1" misalignment at no load in the trolly's way. The other side of the I beam is 0.02" higher than the main beam.. New bushing and pin were greased up with Krytox before installation.
The axial Zerk 1/8" pipe in the pin upper end can not take any fitting. There is no room. It is taped off.
This gap comes down to ~ 1/16" at fully extended arm with 225 lbs load at the end of it.
The present plan is to grind down the the misalignment of 0.1" for a slow-loaded trolly.
Steve Baker of Konacranes will be back to grind down this ridge and load test at 500 lbs on Tuesday, OCT 1, 2013