Thanks to Joe B who made the SRS RGA working with linux
Last data file logged at 2008 Oct 24 with old Dycor unit
First data file logged at 2009 Feb 10 with SRS
Rga scan of day 231 since pumpdown pd66-m-d231
m stands for maglev pumping speed, vacuum normal condition of valves,
cc4 cold cathode gauge at the rga location,
cc1 is real ifo pressure from the 24" tube at the pumpspool,
PEM-count temp: vac envelope temp at the top of IOO chamber
Vacuum normal valve condition was changed to accommodate SRS-RGA calibration.
VM1 was closed to isolate the RGA from the IFO.
Cold cathode gauge CC4 is reading normal.
CC1 is glitching, it is probably dirty.
CC2 is fluctuating too much and it is cutting out for 6-7 minutes. It must be insulated by deposits and there is no emission current.
I think the same goes for P1
They will have to be replaced at the next vent
Vacuum valve configuration is back to VACUUM NORMAL condition. RGA calibration completed.
RGA scan attached is the backgroud of the rga with std cal leak open, sn 08581
Krypton at amu 84 and Argon at amu 40 are the cal signals.
Our Osaka TG360MB maglev failed with CSB error message. This means that the dry emergency landing bearing has to be replaced.
I will consalt with Osaka about the choice of replacing bearing or installing new spare tomorrow.
Mean while V1 is closed and the vac envelope is not pumped.
Valve configuration: BG -background, pumping on the RGA-only
High voltage to IOO PZT steering mirrors and OMC are turned off.
PSL output shutter is closed and manual block is in place.
I will start cooling the CYO pump in the morning, so the IFO will be pumped by noon.
Outgassing plus leakrate after 10 hrs the pressure is 2.3 mTorr
This rate of rise is normal and it is safe to work with the ifo.
The CRYO pump cooled down and VC1 was opened. This valve configuration is Cryo-only
PSL output shutter opened at 4pm
PZT HV power supplies turned on for OMC and IOO steering mirrors.
There positions were not corrected to strain gauge values.
Ben helped us to conclude that the FAILURE led indicator is working correctly and
has nothing to do with the one lose, dangling wire#258 in the side connects of the vac rack.
I reset the CSB switch inside the Maglev controller and tried to start accelerating.
It fails after 2-3 sec and failure led light comes on.
Now we can say the MAGLEV 360 is DEAD and the new OSAKA TG420M can be swapped in.
However it requires new interface with our epics based MEDM or better...?
Ben and I found this vacuum valve relay box intermittently shorthing yesterday.
It effects V4, V5, VA6 and VM1........ Please do not touch this box under the beam pipe next to the vac rack!
The function of this box to send 120VAC to the vacuum valve to move.
I tested the cryopump interlock today. It is touchy. I do not have full confidence in it.
I'm proposing that VC1 gate valve should be kept closed while nobody is working in the 40m lab.
How to open gate valve:
1, confirm temp of 12K on the gauge at the bottom of the cryopump
2, if medm screen cryo reads OFF( meaning warm) hit reset will result reading ON (meaning cold 12K )
3, open VC1 gate valve if P1 is not higher than 20 mTorr
VC1 was closed at 18:25,
IFO condition: not pumped,
expected leak plus out gassing should be less than 5 mTorr/day
The RGA is in bg-mode, annuloses are closed off
In response to Steve's elog entry, and for 40m posterity, I provide the Paschen Curve.
% Paschen Curve plotting
% From http://home.earthlink.net/~jimlux/hv/paschen.htm
% Breakdown voltage:
% Vbreakdown = B * p * d / (C + ln( p * d))
% Breakdown field strength:
% Ebreakdown = p * ( B / ( C + ln ( p * d)))
CC1 5e-7 Torr, VC1 closed at 18:25, IFO is not pumped, RGA is in bg-mode
At about 1am or so Yoichi and I opened VC1. CC1 had fallen to about 5e-5 torr.
Congratulation Yoichi and Peter for full rf locking at night. Let's remember that the cryopump was shaking the hole vac envelope and ifo during this full lock.
The Cryo pump is running reliably since April 22 hence there is no need to close VC1 repeatedly.
The photo switch interlock was put back onto the H2 vapor pressure gauge and it is working.
Our spare Osaka maglev purchased in Oct 2005 turned out to be having a viton o-ring seal connection on the intake.
It was shipped back to San Jose for retrofitting it with 6" conflat flange ( CF ) This CF is using copper gasket so there will be no permeation of He when you leak check the IFO
The digital controller and cable are here. The controller needs to be interfaced with the interlocks and computer system; those have been in a neglected condition lately.
see elog #1505 Historically after every REBOOT of c1vac2 the readbacks works for 3-4 days only. Fixing of this was postponed many times in the past as low priority or lack of knowledgeable
The maglev TG390MCAB wil be back on Tuesday, May 4, 2009. The mourning of our fateful 360 will only end at the first levitation of the 390.
ETMY damping restored.
Cryo interlock closed VC1 ~2 days ago. P1 is 6.3 mTorr. Cryo temp 12K stable, reset photoswitch and opened VC1
CYAN - cryo ON
BLACK - cryo OFF
BLUE - no crappy lens + mount
I found some neat signal analysis software for my mac (http://www.faberacoustical.com/products/), and took a spectrum of the ambient noise coming from the cryopump. The two main noise peaks from that bad boy were nowhere near 3.7 kHz.
Joe and Steve
The retrofitted Osaka 390 was installed on the pumpspool yesterday.
V1 gate valve is disabled for safety by disconnected pneumatic power plug.
The foreline of this maglev now have a KF25 size viton o-ring directly on the turbo.
This is bad for leak hunting.
Joe is ready with new interface cable. Power supply and cables are in place.
The maglev was pumped down this morning.
All new gas kits and metal hose were leak checked by sprayed methanol.
There is no obvious sign of leak. I was expecting the pressure to drop below 1e-5 Torr in one hour.
TP2 is drying out the levitating coils of the turbo at ~7 l/s for N2
We'll start the pump as soon as Joe is in.