Cryostation back online and new policies--please read carefully

Arash Hazeghi ahazeghi at
Wed Sep 3 15:57:10 PDT 2008


I'm pleased to report that after a long down time, cryostation is back
online for business. There were several major issues in the system that have
now been resolved.

1.       Loss of electrical connection in the two lower arms, the miniature
triax cables that connect the feedthroughs to the probe heads had been
twisted badly, as  a result of users trying to change probe tips without my
knowledge. Once again, I emphasize that users are NOT allowed to change or
modify probe tips in the system. If you find tips bent or broken you have to
contact me. 

2.       Back diffusion of oil to the chamber and degraded vacuum, this was
due to the anti-suck-back device failure which had let to oil being sucked
to the turbo. Normally pressure difference is such that with the correct
operation of suck back cup, there should be no diffusion of oil into the
chamber in measurable quantities except for the brief venting period. So,
please keep an eye on your sample, if you see any trace of oil in the
chamber please shutdown and vent the system immediately after warming up to
room temperature. Redlight the tool on coral and notify me. 

3.       Ion gauge failure and incorrect reading, this was again due to the
oil diffusion problem, ion gauge is now replaced and calibrated, notice the
IG sense light is now ON.

4.       Pneumatic isolation system was out of tune, this is due to users
leaning on the table or placing heavy objects on the table. The cryistation
base table is NOT a working surface and you should never lean against it.
Please be careful.

5.       All probe tips were bent. I replaced all tips and they are now in
good shape.


Looking at my account, our group has paid about $1000 worth of tips in the
past 6 months. We can no longer provide users with tips therefore I am
requiring all users to buy and hold 4 X 25um BeCu tips from Lakeshore
( so that I can replace them when broken. Failure to
provide tips will suspend your privileges. Also please log the condition of
the tips in the provided sheet. If you forget to log the tip condition you
will be responsible for providing tips, even if you did not break them.
Finally, as you have figured how difficult it is to fix and maintain this
tool, please be most considerate when operating it. Never leave the tool
unattended for extended periods, fully disengage the tips and retract them
if you have to leave and never leave the transfer line attached to the
system when there is no liquid transfer. 

Thank you for your cooperation and helping to keep the tool operational and
useful for everybody's research.








Arash Hazeghi


PhD Candidate

Stanford Center for Integrated Systems

CIS-X 300, 420 Via Palou Mall, 

Stanford, CA 94305


phone: +1-650-725-0418



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