Sign Language for Scientists

Joshua Halpern jbh at IDT.NET
Mon Jan 25 00:07:03 EST 1999


In sci.chem Mark Tarka <tarka at msu.oscs.montana.edu> wrote:
> In article <78e5vk$pij at nnrp3.farm.idt.net>, Joshua Halpern <jbh at IDT.NET> writes:

> OTOH, I distinctly recall your tirade against the idea of
> field-assisted ionization in the context of laser
> ionization/desorption mass spectrometry..."world-class nonsense" or
> something like that was your comment.

Well your argument certainly was, although I don't recall
using those words.  If the ionization occurs in an isolated
molecule, the field gradient across the molecule, is much
too small.  Briefly, the size of a molecule is of the order of
10^-7 cm.  For a say 20 kV/cm field the field interaction
would be of the order of 0.002 eV for valence electrons
which are photoexcited.  In other words, unless you excite
high lying Rydberg states with large radii, the contribution 
of the field to the energy is about ten times less than
thermal.  See deja news for the details and references 
which I gave.

> I'll certainly announce, if the letter is accepted :-)

Gee Mark, shouldn't do that.  I might see it and you
would then have to eat your letter.  BTW, not everything
that is published is right:)

josh halpern

My last comment on this in this thread and hopefully
forever.



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