Hello
My apology if this has already been covered--we've talked alot
about the how-to's of freezing crystals on this list, but I
don't recall seeing this addressed before.
We would like to be able to "freeze now, take data later", but
have found that frozen crystals stored in liquid nitrogen tend to
accumulate ice crystals over a few months. Some of this frost
can be removed by (very careful) brushing, but even when the
crystals look clean in the telescope, we can still see discrete
diffraction from the ice when collecting data. (These extra
spots are absent in newly frozen crystals.)
Does anyone know of a good way to keep LN2 reasonably dry for
long periods of time? How far in advance do folks generally
prepare their frozen crystals for trips to synchrotron sources?
Lindy Dixon
lindy at biop.umich.edu
Biophysics Research Division
Univ. of Michigan, Ann Arbor
