Billions and Billions of Positrons

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frezik
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Billions and Billions of Positrons

Postby frezik » Tue Nov 18, 2008 4:14 pm UTC

https://publicaffairs.llnl.gov/news/news_releases/2008/NR-08-11-03.html

The artical covers the theoretical implications of this, like figuring out why there's so much more matter than anti-matter. My question for you physicists out there is does this get us into the range where we can economically make several milligrams of anti-matter for manned interplantary missions? (Let's ignore the storage and gamma ray burst problems for now.)

For reference, a NASA press release says we need roughly 10 mg of positrons to get to Mars at a cost of $250 million using bleeding edge techniques at the time (2006).
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Re: Billions and Billions of Positrons

Postby thornahawk » Tue Nov 18, 2008 4:33 pm UTC

I have a not-too-fantastic application in mind: PET scans. :) How might this technology help?

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Re: Billions and Billions of Positrons

Postby 22/7 » Tue Nov 18, 2008 4:47 pm UTC

frezik wrote:https://publicaffairs.llnl.gov/news/news_releases/2008/NR-08-11-03.html

The artical covers the theoretical implications of this, like figuring out why there's so much more matter than anti-matter. My question for you physicists out there is does this get us into the range where we can economically make several milligrams of anti-matter for manned interplantary missions? (Let's ignore the storage and gamma ray burst problems for now.).
According to the article, the gamma ray burst problems are already handled (or at least, they're not nearly the problem they used to be) with the use of positrons instead of antiprotons (a reduction in energy of about 400x). And the storage is done with electric and magnetic fields. Obviously that's easier said than done, but it sounds like it's all very doable.
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Re: Billions and Billions of Positrons

Postby Terebrant » Tue Nov 18, 2008 5:25 pm UTC

thornahawk wrote:I have a not-too-fantastic application in mind: PET scans. :) How might this technology help?

~ Werner

I don't see this technology helping much in (s)PET scans except, maybe, in designing new collimator and such but you will not get new (useable) tracers or way to generate them which is what would be really useful.

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Re: Billions and Billions of Positrons

Postby Soralin » Tue Nov 18, 2008 10:49 pm UTC

frezik wrote:https://publicaffairs.llnl.gov/news/news_releases/2008/NR-08-11-03.html

The artical covers the theoretical implications of this, like figuring out why there's so much more matter than anti-matter. My question for you physicists out there is does this get us into the range where we can economically make several milligrams of anti-matter for manned interplantary missions? (Let's ignore the storage and gamma ray burst problems for now.)

For reference, a NASA press release says we need roughly 10 mg of positrons to get to Mars at a cost of $250 million using bleeding edge techniques at the time (2006).


Well, let's see, a positron weighs about 9.109×10−31 kg, so a mg of positrons would be a bit more then a trillion trillion of them, so still a bit short :)

Although you might be able to get a bit more of a bang out of them by some other method, what about something like antimatter initiated fusion? Antimatter catalyzed nuclear pulse propulsion (unless that was already taken into account) Or do the same for energy production, figure out some way of using it with Inertial Confinement Fusion to rapidly compress a small bead of deuterium and tritium, if it could be produced efficiently enough.

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Re: Billions and Billions of Positrons

Postby Woofsie » Tue Nov 18, 2008 10:58 pm UTC

Well, Antimatter catalyzed nuclear pulse propulsion uses antiprotons, I'm not sure if it could be done with positrons.

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Re: Billions and Billions of Positrons

Postby Soralin » Tue Nov 18, 2008 11:06 pm UTC

Woofsie wrote:Well, Antimatter catalyzed nuclear pulse propulsion uses antiprotons, I'm not sure if it could be done with positrons.


Hmm, yeah, they way they have it there, the antimatter splits the nuclei apart, and generates a ton of neutrons to start the process. Positions might be useful in something like inertial confinement though, just as a means to produce a bunch of concentrated force in a small period of time, although you'd have to figure out a good way to use them. If you could figure out a way of containing them in a thin shell around the bead without all that extra equipment like huge magnets and such, that would be great, just hit that with the laser as normal and get a bit of extra push when the positrons get forced in. Otherwise you'd have to figure out a way of delivering them to the target all at once in a big burst in a controlled way. Although it seems like it would be easier with antiprotons (except for making them).


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