Exotic Propulsion ?

Nuclear fission converts about 1 part in 200 of the nucleon rest mass
to energy.

Nuclear fusion converts about 1 part in 20 of the nucleon rest mass to
energy.

Anti-matter/matter annihilation converts 100% of the rest mass to
energy.

The problem is getting anti-matter.

But what if anti-matter could be made on demand?

Consider that by bombarding Oxygen 18 - which is stable and has an
abundance of 1/5th percent - with a neutron makes it into Oxygen 19.
This is unstable and in a few seconds decays into Flourine and an
ANTI-NEUTRON.

Now, this anti-neutron decays in a short time to an anti-proton and
positron.

The interesting thing is that the anti-neutron mass is about 1/19th
the combined mass and that if the anti-neutron combines with a neutron
in the Flourine atom - about 1/9.5th - a little more than one part in
10 - of the nucleon rest mass is converted to energy.

Is this even right? If so, are there better materials?

What's wrong with this picture?

(I've been emboldened to mention this notion after reading about
quantum entanglement as a propulsion scheme! )

If this works we can take a weak stream of neutrons process them in a
way to make a powerful stream of gamma rays.

I need more information though.

Also, if this works we might have a very controllable and safe source
of energy. Implemented as a micro rocket array (neutron source,
neutron/anti-neutron conversion process, energetic particle stream -
all built tiny and occurring as a huge array across a propulsive skin)
it would be sci-fi style space vehicles would be possible!

Exhaust speeds could approach 32% the speed of light - and power
levels would be very high. With high thrust to weight, and minimal
propellant - all manner of propulsion modules are foreseeable.

william mook wrote:

Consider that by bombarding Oxygen 18 - which is stable and has
an abundance of 1/5th percent - with a neutron makes it into
Oxygen 19. This is unstable and in a few seconds decays into
Flourine and an ANTI-NEUTRON.

Are you sure about this, William? Every reference I've checked says
that O-19 decays into F-19 (which is stable) via beta-minus decay.

Jim Davis

william mook wrote:
[...]
Consider that by bombarding Oxygen 18 - which is stable and has an
abundance of 1/5th percent - with a neutron makes it into Oxygen 19.
This is unstable and in a few seconds decays into Flourine and an
ANTI-NEUTRON.

Unfortunately, this seems not to be the case --- when oxygen-19 decays into
flourine-19, it emits an electron and an anti-*neutrino*. Which, alas, is a
quite different thing to an anti-neutron.

http://education.jlab.org/itselemental/iso008.html

[...]
Also, if this works we might have a very controllable and safe source
of energy. Implemented as a micro rocket array (neutron source,
neutron/anti-neutron conversion process, energetic particle stream -
all built tiny and occurring as a huge array across a propulsive skin)
it would be sci-fi style space vehicles would be possible!

It would be nice if it worked. The net effect would be that you feed
oxygen-19 into a reaction chamber, bombard it with neutrons, and you get
really hot flourine-19 that can be used as your exhaust. Stable and
efficient... it's a pity that the universe doesn't seem to like that sort
of thing. AFAIK the only way of producing antiparticles is to pump stonking
great quantities of energy into a particle accelerator and hope that when
your particles collide, antiparticles are created.

--
+- David Given --McQ-+ "There does not now, nor will there ever, exist a
| | programming language in which it is the least bit
| ) | hard to write bad programs." --- Flon's Axiom
+- www.cowlark.com --+

"David Given" wrote in message
...
william mook wrote:
[...]
Consider that by bombarding Oxygen 18 - which is stable and has an
abundance of 1/5th percent - with a neutron makes it into Oxygen 19.
This is unstable and in a few seconds decays into Flourine and an
ANTI-NEUTRON.

Unfortunately, this seems not to be the case --- when oxygen-19 decays
into
flourine-19, it emits an electron and an anti-*neutrino*. Which, alas, is
a
quite different thing to an anti-neutron.

http://education.jlab.org/itselemental/iso008.html

If Oxygen-19 did decay with the emission of an anti-neutron, it would have
to gain a neutron or proton in the nucleus to maintain conservation of
baryon number, and thus become either O-20 or F-20, an interesting decay
process in which about 2 GeV of mass-energy (the two new nucleons) appear
from nowhere.

David Given wrote in message ...
william mook wrote:
[...]
Consider that by bombarding Oxygen 18 - which is stable and has an
abundance of 1/5th percent - with a neutron makes it into Oxygen 19.
This is unstable and in a few seconds decays into Flourine and an
ANTI-NEUTRON.

Unfortunately, this seems not to be the case --- when oxygen-19 decays into
flourine-19, it emits an electron and an anti-*neutrino*. Which, alas, is a
quite different thing to an anti-neutron.

http://education.jlab.org/itselemental/iso008.html

[...]
Also, if this works we might have a very controllable and safe source
of energy. Implemented as a micro rocket array (neutron source,
neutron/anti-neutron conversion process, energetic particle stream -
all built tiny and occurring as a huge array across a propulsive skin)
it would be sci-fi style space vehicles would be possible!

It would be nice if it worked. The net effect would be that you feed
oxygen-19 into a reaction chamber, bombard it with neutrons, and you get
really hot flourine-19 that can be used as your exhaust. Stable and
efficient... it's a pity that the universe doesn't seem to like that sort
of thing. AFAIK the only way of producing antiparticles is to pump stonking
great quantities of energy into a particle accelerator and hope that when
your particles collide, antiparticles are created.

Yep. I eloquently responded to this two weeks ago.

[/RANT] Why the hell hasn't it been posted yet. Yet, this stuff
hangs out here. Meanwhile, my responses get buried in a load of crap
almost as fast as I post them. What's up with that? Its as if
someone were waiting to figure out a negative response to what I'm
saying before they let it post - if it gets posted at all! [/RANT]

Okay, now that I've got that off my chest, let me attempt to repeat
what I've said earlier - though, likely not with the same eloquence!


There was an .edu site that had a typo, they wrote anti-neutron
instead of anti-neutrino - and that led to my confusion.

http://www.hbcumi.cau.edu/tqp/451/45...02/451-02.html

Notwithstanding this confusion the question still remains, is there a
reaction train in the massive transformation matrix given here;

http://ie.lbl.gov/isoexpl/isoexpl.htm

that allows the production of an anti-neutron?

If so, we have a way to produce a lot of anti-matter very cheaply.
And since fusion and fission operate by mass differences smaller than
1 amu and any reaction that produces 1 anti-neutron would cause a 2
amu conversion of matter to energy - we obviously have a massive new
energy source - if such a transformation can take place.

If its neutron mediated -that is by adding a neutron to an ultra-heavy
nucleus - then it should look a lot like fission engineering wise,
except being more powerful than fusion and having nicer reaction
products (perhaps).

A bomb might be possible, some sort of neutron pulse from a fission
device that floods the hypothetical anti-matter producing material to
dramatically increase device yeild, reduce device mass, or both.

If such a process existed would anyone classify it?

(Henry Spencer) wrote in message ...
In article ,
william mook wrote:
Consider that by bombarding Oxygen 18 - which is stable and has an
abundance of 1/5th percent - with a neutron makes it into Oxygen 19.
This is unstable and in a few seconds decays into Flourine and an
ANTI-NEUTRON.

Um, references? Lederer et al, "Table of Isotopes", 6th ed, says O-19
decays to F-19 by perfectly ordinary beta decay -- it emits an electron,
not an antineutron. (And since an antineutron is uncharged, O-19 decaying
that way would yield another oxygen isotope, not fluorine.)

Without having looked into the matter closely, I doubt antineutron decay
is even physically possible. Electrons, positrons, protons, neutrons, and
alpha particles, yes, plus assorted gamma rays and sometimes X-rays, but
antineutrons?

I have attempted to respond to this SEVEN TIMES over the past month.
There is an .edu reference that mistakenly wrote 'anti-neutron'
instead of 'anti-neutrino' - which I've explained repeatedly,
unfortunately NONE of the posts have made it to the thread - despite
the fact that the moderator has approved them all according to a
private e-mail.

"Christopher M. Jones" wrote in message ...
william mook wrote:
Notwithstanding this confusion the question still remains, is there a
reaction train in the massive transformation matrix given here;

http://ie.lbl.gov/isoexpl/isoexpl.htm

that allows the production of an anti-neutron?

No. For very straightforward reasons, no naturally
occuring nuclear decays result in the emission of
anti-nucleons of any sort.

Well, anti-neutrinos modify nucleons.

However, there are
isotopes which decay via emission of positrons,
though these are almost always captured by nearby
electrons and annihilated into gamma rays very
quickly.

Yes, releasing ~1/930th the rest mass of a neutron to energy. Which is
weaker than nuclear fusion and fission - but stronger than chemical
interactions.

So, this might be interesting as a power source - not as powerful as
one that hypothetically (though sadly not existing) produces an
anti-neutron!