JWJ%MIT-MC@sri-unix.UUCP (09/29/83)
From: Joseph W. Johnson <JWJ @ MIT-MC>
Now it should be noted that if pure deuterium is burned,
the reaction only produces helium nuclei. There are no neutrons
and hence no neutron induced radioactivity and no neutron
damage to the materials...
Unfortunately, this is not quite true. In deuterium-deuterium fusion,
there are two reaction paths, one produces a Helium-3 nucleus and a proton.
The other produces tritium and a neutron. The two branches happen with almost
equal probability. If we consider that the energy yield from either branch is
approximately 4 MeV while the yield from a deuterium-tritium fusion is 17.6 MeV,
its apparent that there will be more neutrons produced (per unit energy) in a
pure deuterium plasma than in the D-T plasma (although the D-D neutrons will be
of lower energy). The bottom line is that any reactor that contains deuterium
will produce neutrons from D-D fusion. There are reactions, such as a proton
fusing with Boron-11, which do not produce neutrons, but confining and igniting
such a plasma would be considerably more difficult than the D-T plasmas which
form the basis for most fusion reactor designs.
Joe JohnsonDCP%MIT-MC@sri-unix.UUCP (09/29/83)
From: David C. Plummer <DCP @ MIT-MC>
Date: 29 September 1983 07:27 EDT
From: Joseph W Johnson <JWJ@Mit-Mc>
Subject: fusion -- deuterium reactions
To: physics @ Sri-Unix
In-reply-to: Msg of 4 Oct 83 2:02:51-EDT (Tue) from pur-ee!CSvax.Pucc-H.pur-phy!piner at Ucb-Vax
Hey, that's cute. Did somebody discover time travel while we
weren't looking? I.e., look at the Date: and In-reply-to: fields.