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Re: Radiation lesson
> From: Wright Huntley <jwwiii at pacbell_net>
> Subject: Radiation lesson.
> Electromagnetic radiation comes in lots of useful forms.
> The kind most used for sterilizing is usually called ionizing radiation. That
> can be anything from visible light and UV through soft to hard x-rays. While
> capable of inducing serious chemical changes, and certainly of destroying
> living tissue (right dose and wavelengths),
The shorter the wavelength, the more the ionisation, because each
photon has more energy. This refers to electromagnetic radiation.
> Particle bombardment with neutrons and electrons (alpha and beta "rays")
Alpha particles are helium nuclei. Neutrons aren't ionising
> penetrate some materials and can cause residual radioactivity if they actually
> split atoms into unstable isotopes.
Neutrons can cause fission of uranium, thorium and plutonium (if you
hit the right isotope). They are readily absorbed by _lots_ of other elements,
causing the formation of a higher mass number isotope of the same element.
_That_ may well be unstable (usually a beta emitter). The phenomenon is
very useful for analytical purposes - I've used it.
> The kind used for killing salmonella in
> ground beef is most unlikely to ever do that. It takes a pretty big
Usually pretty hard gamma rays from very high energy electrons.
Anything that kills bacteria is going to finish off the plants, I think.
Paul Sears Ottawa, Canada