Hello Darren The original post never made it to my mail box. To the original posters questions about metal detectors:
One of the points to be made is that a metal detector only detects free metal not elements. It is a "field test" and searching for specific elements is a "lab test' As they say on the American TV Game Show-- Family Feud --"gudanzer"! my I say--"gudlinks". Elton --- On Sun, 3/15/09, Darren Garrison <cyna...@charter.net> wrote: > >A- measuring on the field/ meteorite finding/ first testing: > >I read often that finders/hunters use magnets. What > about a metal detector measuring Iridium ? > >or is Iridium detection too close to other elements, or too small in content > >to be singled out ? and what about Osmium ? or Technetium ? > > > >B- testing > >How is Iridium (or Osmium, or Technetium) analysed and > tested ? Is there any non-invasive way to test one or more of > them, to keep the meteorite "as is" ? > > I was sitting here trying my best to remember the name of a > type of measurement used to find very small amounts of atoms in materials (as > is often the case) it > wasn't coming to me. Fortunately I remembered it being > described in a book by Walter Alverez called T. rex and the Crater of > Doom,searched down my copy and was reminded that it is "neutron activation > analysis". Good book on the > detective work behind the discovery of the iridium (and > other rare element) concentrations at the K/T boundary. You should try to > get your hands on a copy. You can preview big chunks of it on Google Books: > http://books.google.com/books?id=kkHhl67ixwEC&printsec=frontcover&dq=rex+and+the+crater+of+doom#PPA66,M1 > > Use the right-hand search window to search for > "neutron activation analysis" in > the book. > > http://en.wikipedia.org/wiki/Neutron_activation_analysis > > As for technetium, I wouldn't hold my breath about > finding much of it. Very > short half life, both in human terms for some isotopes > (hours to days) and in cosmic terms (at most a few million years, a blink of > the eye in the age of a > meteorite). The amount (from some googling) produced > naturally by uranium decay and neutron absorbtion in molybdenum seems to be > vanishingly small. Doesn't > look to be much to be a mesurable amount to picked up from > the solar wind (though this article is pretty old) > http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005aca_407.pdf > > Here's an article touching on the decay products of > technetium in meteorites: > > http://wwwsoc.nii.ac.jp/jnrs/paper/JN63/jn6325.pdf > > and another: > > http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1877.pdf ______________________________________________ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list