Mössbauer spectroscopy is a
spectroscopichttp://en.wikipedia.org/wiki/Spectroscopytechnique
based on the recoil-free, resonant absorption and emission of gamma
rays http://en.wikipedia.org/wiki/Gamma_ray in
solidshttp://en.wikipedia.org/wiki/Solid.
This resonant emission and absorption was first observed by Rudolf
Mössbauerhttp://en.wikipedia.org/wiki/Rudolf_M%C3%B6ssbauerduring
his graduate studies in 1957, and is called the Mössbauer
effect http://en.wikipedia.org/wiki/M%C3%B6ssbauer_effect in his honor.
Mössbauer received a Nobel Prize in 1961 for this work.
Like NMR spectroscopy http://en.wikipedia.org/wiki/NMR_spectroscopy,
Mössbauer spectroscopy probes tiny changes in the energy levels of an atomic
nucleus in response to its environment. Typically, three types of nuclear
interaction http://en.wikipedia.org/wiki/Nuclear_interaction may be
observed: an isomer shift http://en.wikipedia.org/wiki/Isomer_shift, also
known as a chemical shift
http://en.wikipedia.org/wiki/Chemical_shift; quadrupole
splitting http://en.wikipedia.org/wiki/Quadrupole_splitting; and, magnetic
or hyperfine splitting http://en.wikipedia.org/wiki/Hyperfine_splitting,
also known as the Zeeman effect http://en.wikipedia.org/wiki/Zeeman_effect.
Due to the high energy and extremely narrow
linehttp://en.wikipedia.org/wiki/Spectral_linewidths of gamma rays,
Mössbauer spectroscopy is one of the most sensitive
techniques in terms of energy (and hence frequency) resolution, capable of
detecting change in just a few parts per 10e11.
Depending on the local environment of the Fe atoms and the magnetic
properties, Mössbauer spectra of iron oxides can consist of a singlet, a
doublet, or a sextet. If the iron is superparamagnetic a telltale hyperfine
sextet structure will be detected.
On Thu, Apr 14, 2011 at 11:26 PM, francis froarty...@comcast.net wrote:
Jed wrote [snip]
Focardi says some things that are supposed to be confidential. I will leave
it to the reader to find those bits, as an exercise. He's got a big mouth.
I'll bet this ruffles some feathers![/snip]
Focardi says “and then there's this chemical compound. The issue came up
during that demonstration because, when some people tried to measure the
gamma rays, Rossi objected, because by measuring the gamma rays they would
have also measured the gamma rays emitted by this secret compound, and so
they would have understood what it was, what was in it.”
He is revealing that it is a chemical compound that emits gamma rays…. That
it participates in the nuclear reaction?
Fran
