[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
Steve Baker of Konecranes will be back to grind down this ridge and load test at 500 lbs on Tuesday, OCT 1, 2013
Konecranes rescheduled the completion of the Vertex crane to Wednesday, Oct. 2
The smoke alarms were turned off and surrounding areas were covered with plastic.
The folding I-beam was ground down to be in level with the main beam.
Load bearing cable moved into correct position. New folding spring installed.
Crane calibration was done at 500 lbs at the end of the fully extended jib.
Than we realized that the rotating wheel limit switch stopped working.
This means that the crane is still out of order.
New limit switch will be installed tomorrow morning
Konecranes postponed installation Friday morning Nov. 8
Friday 5pm : Konacranes promising to be here 8am Monday, Nov 11
It was rescheduled on Tuesday again for Wednesday, Nov 13
New limit switch installed and tested. The crane is back in full operational mode. Two spare limit switches on hand.
Instrument rack power supplies checked and labeled at present loads.
The vacuum rack Sorensen is running HOT! Their is only 0.3A load at 24V There is plenty of space around it.
It is alarming to me because all vacuum valve positions are controlled by this 24V
The temperature went down to room temp with temporary fan in the back. Voltage and current are stable.
Regardless, it will be replaced early next week.
It was a bad experience again with our vacuum system. The valves went crazy as we rebooted the computer. This was required for the swap in of a good 24V power supply.
The IFO was vented to 27 Torr through the annuloses, VA6, V7, Maglev,VM2 and VM1 (VC2 was open too)
I just opened the PSL shutter after a 4 hours pumpdown.
Condition: annuloses are not pumped, the IFO and the RGA are pumped as Atm2 shows
I will be here tomorrow morning to switch over to vacuum normal.
More details later
I'm leaving the 40m now. IFO is aligned. Everything look good.
- The main volume P1=5e-4, CC1=1.4e-5 is still pumped by TP1 and TP2
- RGA P4<0e-4, CC4 2.1e-7, is pumped by TP3
- The annuluses are isolated.
- RP1/2/3 are off.
The recovery- pumpdown reached valve configuration vacuum normal at 20 hours, cc1 7.7e-6 Torr
Lesson learned: turn all pumps off, close all valves before you reboot ! like you would prepare for AC power shut down.
The date is correct on this monitor.
Last stored RGA scan data Dec 20, 2013
IFO pressure at CC1 5.8e-6 Torr
Valve configuration: Vacuum Normal, confirmable only by manual checking of position indicators and pressure gauge controllers readouts
We probably need to restart the machine, but I didn't want to touch c1vac1 and c1vac2.
Events of the power supply swap:
1, Tested 24V DC ps from Todd
2, Closed V1, VM1 and all annulos valves to create safety net for the reboot. Turbo pumps left on running.
3, Turned computer off
4, Swap power supplies and turned it on
5, Turning the power on of c1vac2 created caos switching of valves. This resulted in a air vent as shown below.
6, VM1 was jammed and it was unable to close. The IOO beam shutter closed and the IFO was venting with air for a few minutes. Maglev did an emergency shut down. TP2's V4 and TP3' V5 closed. RP1 and RP3 roughing pumps turned on, their hose was not connected as usual. The RGA shut down to protect itself.
7, Closed annulos valves, stoped the vent at P1 27 torr as the vacuum control was manually recovered
8, The Maglev and the annuloses were roughed out 500 mtorr . The Maglev was restarted.
9, The IFO pump down followed std procedure from 27 torr. VM1 was moving again as the pressure differential was removed from it.
Remember: next time at atm .....rough down the cryo volume from 27 torr !