Noble gases

[Les Slaback <lester.slaback@nist.gov>]

A few random memories:
Ed Rank at NRL did a paper 15-20 yrs ago on a NaI monitoring process using a compressed volume to monitor Ar-41.

In terms of separation Mike Unterweger at NIST uses cryogenics to condense noble gases (Xe, Kr) and then distribute them in controlled alliquotes for radioactive standards.  I know that if there is any air contaminates he has big problems getting a quantitative collection.
Disclaimer:  the above are the personal musings of the author, and do not represent any past, present, or future position of NIST, the U.S. government, or anyone else who might think that they are in a position of authority.
Lester Slaback, Jr.  [Lester.Slaback@NIST.GOV]
NBSR Health Physics
Center for Neutron Research
NIST
Gaithersburg, MD  20899
301 975-5810