All it takes to knock neutrons out of a nucleus is energy, so of course
photons can do this. But in general (for the sort of common elements we
find in meteoroids) it takes a _lot_ of energy. You need photons with
gamma ray energies (which is also what the reference you list says).
Gamma ray photons are far more energetic than the visible light photons
you see (literally) in meteors. Gamma rays have not been associated with
meteors, nor with impacts.
Meteors heat up the air, which causes it to ionize. That is, electrons
get stripped from atoms. That takes a lot less energy than breaking up
atomic nuclei. Some atoms simply get electrons kicked into higher energy
states, and visible light photons are released when the electrons relax
back to lower energy states. Nobody has much idea about what causes
electrophonic noise, but one theory suggests it might be turbulence of
ionized gas in the meteor wake. In any case, however, all of these
phenomena involve energies that are five or six orders of magnitude
lower than what's required to produce neutrons.
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
----- Original Message -----
From: "E.P. Grondine" <[EMAIL PROTECTED]>
To: <meteorite-list@meteoritecentral.com>
Sent: Friday, December 28, 2007 11:08 AM
Subject: [meteorite-list] Neutron and Proton production in
hyper-velocityimpacts
Hi all -
Over the last several days, I've cited several C14
spikes associated with hyper-velocity impacts.
It turns out that photons can release neutrons and
protons from a nucleus:
http://galileo.phys.virginia.edu/classes/252/Nuclear_Notes/nuclear_notes.html
To give you idea of the energies involved, we've all
watched the photons given off by meteors traveling at
cosmic speeds. If I remember right, those photons come
from excited electrons - as does the electrophorenic
sound discussed so many times here on the list over
the years.
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