Re: Can someone answer these simple questions for a layman re. fusion?

David, on final thought...

As I'm quite sure that you realize, hydrogen fusion is relatively easy
to accomplish.

The challenge for science today is the production of controlled,
continuous fusion process that operates at a level greater than the
break-even energy point. Our sun appears to have this technology
mastered, but on a lesser scale, it remains a mystery to man.

....Call this final comment simply "lecturing to the choir".

Harry C.




David wrote:
On 24 Aug 2006 19:01:14 -0700, hhc314@xxxxxxxxx wrote:

David, I'm a physicist and I believe you're mostly on target except for
a few minor points.

With respect to your first point, the result of H + H fusion is
conceptially no different from the fustion of deuteriium and tritium
(both hydrogen isotopes) except for the fact that the fission cross
sections are different. (How very different they are remains a point in
disputed among scientists.)

You then ask how is the energy of such a fusion reaction released?
Good question. The majority of the energy release would likely be in
the form of electromagnetic radiation and gamma rays, plus the ejection
of some very energetic neutrons.

Your #3 is right on, and the energy produces would be like absorbed in
some sort of an absorbent material such as graphite, converted to heat,
and employed to produce steam that would fuel a turbine driving a
generator.

In question #4 you raise the question of what is a "barn". In
simplified terms it is the statistical representation of a fusion even
taking place under specified conditions (say temperature, pressure,
etc.). In this sense temperature refers to reactant velocity and
pressure to the density of potential reactants. See, for example:

http://ed.fnal.gov/painless/htmls/cross.html

With regard to cold fusion, I won't even venture an opinion, since over
the past 10 or so years I have seen no compelling experimental evidence
since such an effect even exists, and have to encounter theoretical
knowledge to suggest that it should.

Kindest regards, Harry C.


Thank you.

The uranium nucleus is 'as big as a BARN'... nice I like that! =8-)
That makes sense. Also the physical size of the nucleus is only part
of the story... it has an area of influence too that determines
whether particles passing close get pulled in and 'assimilated'! Mmmm.
I'll have to read more about that.

From reading the literature, slow moving particles seem to have a
better chance of reacting with the nucleus than fast movers that can
potentially cause knock-outs. All this would suggest that slow,
sluggish surges of interaction may have a better chance of bringing
about fusion than a short period of fast, cataclysmic high-speed
collisions. The latter work but are energy-intensive to bring about.

I agree to some extent re. cold fusion. Giga watt lasers vapourizing
microscopic D-T filled capsules works, even if the power out is tiny
compated to the power you have to put in whereas hoping that a few
hydrogen atoms locked in a palladium matrix might fuse in some
'interstitial' gaps, or wherever, as if by magic, hope and electric
field oscillation doesn't seem to be doing the job. I do know that one
side will succeed eventually. Who knows!

I am very interested in fusion and this means that all my time reading
web pages has, at least to some extent, been absorbed and I'm thinking
on 'pretty much' the right lines.


Thanks again.

regards


David

.

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