minigenerators

[Jack Couch <jgcouc@planetx.bloomu.edu>]

John, 
You may get a flurry of replies on this. It was a thread topic a few months
back. The old style generator that we all liked so well is no longer
manufactured. I don't know the history, but it must have been
profit-related. Oxford Instruments and a number of school science equipment
companies market a new version.

Oxford Instruments, Inc.
P.O. Box 2560, 
601 Oak Ridge Turnpike
Oak Ridge, TN 37831-2560
1-800-7-Oxford

A 1995 price sheet lists it at $150
Its called the Model M-2 Isogenerator, the activity of the parent Cs-137 is
9 microCi, and they recommend 0.1m EDTA solution rather than acid. I think
we have ruined a couple of ours using acid. 

Our experience is that a lot of the Cs-137 leaches through, so if you are
going to use it for half-life measurements of 2.6 min Ba-137m, count for a
half hour, draw a horizontal base line back to zero time and subtract that
as "background" instead of ambient lab background. We get pretty good
results doing it that way. Two irksome problems: (1) Because of the new
design, you are bound to drip solution on your fingers (wear protective
gloves, of course), and (2) you have to deal with the Cs-contaminated fluid
when you finish. Good luck.

Jack Couch
Bloomsburg University