Hi,
If you have ice on the crystal (loop) but no blockages of the cryostream
itself (and this seems to be what you're saying), it is unlikely to be a
problem with the LN2 (although I only have experience with Oxford
Crystreams, but I imagine this also applies to X-streams).
Our main problems are turbulence (collimator poking into the gas
stream(s) or gas 'bouncing' back from something just beyond the crystal
- moving things even a little may help here) and drafts due to
'powerful' air-conditioning.
As you state that one of your setups is affected and not the other, it
may well be the case that an air conditioning vent is blowing onto your
setup, and disturbing the gas streams. We resorted to hanging plastic
sheeting around two sides of our set-up and this made a vast difference.
HTH,
Johan
Mark Agacan wrote:
Apologies for this slightly off topic question:
I am having a great deal of trouble with my X-Stream 2000 cryostream system and I wondered if other users have similar problems.
I've replaced almost all components (new GAST compressors, helium recharges, filters, etc., etc.) in the last couple of months but there is almost always icing of any cryo within 10 - 20 minutes of mounting a loop, and it is adversely affecting data collections.
It appears like there is too much moisture in the cold or wam streams but the tubes have been fully dried out as per Rigaku advice.
This X-Stream is attached to a generator with inverted phi axis and and i'm wondering if this could be the source of the problem, as the X-Stream for another generator in the same laboratory with normal phi axis does not ice up. Can some sort of turbulence around the loop caused by backdraft from the cryo hitting the inverted phi axis / camera mount cause excess humidity and lead to icing on the pin, loop and crystal?
Has anyone else got this problem? Any suggestions would be very gratefully
appreciated.
Best Wishes,
Mark
_
Dr Mark Agacan
Scientific Officer,
Division of Biological Chemistry
and Drug Discovery,
Wellcome Trust Biocentre,
College of Life Sciences,
Dow St.,
University of Dundee,
Dundee, DD1 5EH
Tel: +44 1382 388751
Fax: +44 1382 345764
_
The University of Dundee is a registered Scottish charity, No: SC015096
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Dr. Johan P. Turkenburg X-ray facilities manager
York Structural Biology Laboratory
University of York Phone (+) 44 1904 328251
York YO10 5DD UK Fax (+) 44 1904 328266
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