Is there a Theoretical Physicist in the house? Antimatter Question inside

I'm having trouble finding an answer to Antimatter/Matter reactions. I know that when the same particles of matter and Antimatter meet they annihilate and release in pure energy. But I have been wondering for sometime now what happens when dissimilar forms of Matter and Antimatter meet, such as a heavier element of Matter and lighter element of Antimatter. Would it still result in pure annihilation, or would there be remaining parts to the heavier element as well as the resulting energy release?

Searches on the Internet have been pretty fruitless, focusing more on same element annihilation, and given the eclectic knowledge base of these forums I figure somebody might have an answer.

The answer is "probably".

Basically, you're looking at the annihilation on an atomic level, when the reaction is subatomic.

So if you had an atom of Anti-Lithium collide with an atom of, say, Nickel, then you would (presumably) be left with some Manganese. (More likely, the atom of nickel would be blown apart and you'd be left with a soup of subatomic particles.)

The real question is whether complex elemental antimatter can form. We've so far isolated anti-hydrogen and anti-helium, but there seems to be a real bias in the universe against anti matter. So you can't really answer the question because we don't have large amounts of antimatter lying around, but I think my science is sound.

In therex's Anti-Lithium/Nickel reaction, I come down in the blown apart and soup of subatomic particles camp. The amount of energy released when the anti-matter/matter annihilation takes place is going to have no problem blowing apart whatever is left of the matter atom (and probably a bunch of other stuff in the vicinity).

Disclaimer: I haven't done the math, and it's been a decade and a half since my last physics class.

It can all be explained with the ~Large Hadron Collider Rap~

Thats in line with what I was thinking, but I hadn't found any evidence of further research in the matter, real or theoretical.

The next question would be what would the ejecta soup consist of. Obviously lots of subatomic particles due to the amount of energy being released during annihilation.

The reason I ask is I'm trying to figure this out is for a Sci-fi storyline. Obviously good Sci-fi technology is a careful mix of real science and poetic license, so I'm trying to make sure the concept in my mind won't make someone with rudimentary understanding of the reactions roll their eyes when hearing about it.

The concept as follows: Lighter element Antimatter and a Heavier element of Matter are accelerated and meet in a main reaction chamber. The resulting reaction results in a massive release of energy, most of which is collected and transfered into electrical power for the vessel. The remains of the matter is supposed to come out and provide a stream of plasma thats used for Newtonian type propulsion.

The Newtonian thrust is secondary mode of propulsion so maximum nozzle velocity is not of major concern, as I know there are more efficient and higher power matter/antimatter rockets in working theory. But I'm not sure if the remaining matter could be considered a plasma state of would just be a useless gobbledy gook of sub atomic particles.

yeah. But you have to consider that up to half of a matter/antimatter reaction goes into neutrinos which isn't really much good (for our purposes), and the rest goes into kinetic energy.

So, if we have a 100th of a milligram of elemental hydrogen (I use hydrogen because there's no neutrons so it makes my math easy) and slam it into an equal amount of antihydrogen, I'll get maybe one of those masses out in kinetic energy, which I could maybe use.

So that's 898755179 joules. Alot, but enough to overcome nuclear forces in a nickel atom standing closeby minding it's own business? And 100th of a milligram is still alot of atoms. That's why I said "more likely" do end up with the plasma soup...because I'm not sure what would happen.

Realistically, you're not going to be storing anti-atoms anyway. An antiproton is much easier to store than an anti-hydrogen (or whatever) because a of it's polar charge. You could store these -p's in a magnetic bottle, while you can't really do that with an anti-atom because it would be magnetically neutral.

But "a plasma state" and "a gobbledy gook of sub atomic particles" are essentially the same thing. :)

So in other words I've made up a concept that with some refining, isn't completely unfeasible.

Anti-Protons and and a Matter element are introduced together. Annihilation ensues resulting in Kinetic energy, and presumably a soup of remaining subatomic particles which could be the "plasma soup" or would a third fuel need to be injected to create a more viable plasma exhaust.

To help the concept running about in my head I'd need a way to convert the Kinetic energy to an electrical source, or would it make more sense to have the resulting post reaction plasma run some manner of generator?

What would be a good matter fuel to mix with the Anti-Proton?

Have you read this yet?

http://www.nasa.gov/centers/goddard/news/topstory/2006/antimatter_spaceship.html

or this:

http://ffden-2.phys.uaf.edu/213.web.stuff/Scott%20Kircher/plasmacore.html

So nobody's building an antimatter injection kit then? What a let-down.

GameboyRMH wrote: So nobody's building an antimatter injection kit then? What a let-down.

I think they'd have trouble staying under the $2008 budget.

Plus I heard that improper injection can lead to engine problems. Apparently they don't so much "hand-grenade" as "tear rifts in space-time". Rifts in space-time are notoriously difficult hazards for crews to clean from a track surface.

Salanis wrote:

GameboyRMH wrote: So nobody's building an antimatter injection kit then? What a let-down.

I think they'd have trouble staying under the $2008 budget. Plus I heard that improper injection can lead to engine problems. Apparently they don't so much "hand-grenade" as "tear rifts in space-time". Rifts in space-time are notoriously difficult hazards for crews to clean from a track surface.

Just richen the mixture a bit and put a high-flow cat on the car, that should minimize the damage to the universe

Odd the second link appears broken, but I already had the page open in another tab, weird. I had seen the first link previously too.

Although they both seem to be looking at raw kinetic force for propulsion, but I do see how it converted to the drive setup I was looking for.

I just have to nail down a couple items, the reactor is supposed to create a constant and variable flow of Plasma and a massive electrical power supply. For the purposes of the story there are times when it would be more ideal to be running more electrical power than plasma when the vessel's primary drive is engaged.

Secondly, Matter/Antimatter reaction all create Gamma rays, would it be beyond believable means to say somehow someone found a way to harness Gamma Rays into an electrical power source. Where a higher energy reaction such as in anti-proton reactions would end up becoming more desirable, versus the safer Positron reaction.

neckromacr wrote: Secondly, Matter/Antimatter reaction all create Gamma rays, would it be beyond believable means to say somehow someone found a way to harness Gamma Rays into an electrical power source. Where a higher energy reaction such as in anti-proton reactions would end up becoming more desirable, versus the safer Positron reaction.

See: http://en.wikipedia.org/wiki/Pair_production

That would generate electricity directly, perhaps bathing some superconducting material in gamma rays?

Outstanding I like it, everything makes sense and is jiving well, which allows me to write it so it sounds like it could work.

Thanks for the help.

When they crank up the supercollider in Europe this month, a lot of the theory will be either dispelled or confirmed. I understand the folks over there in charge of it are giddy as schoolgirls with anticipation. I'd hold off on locking down the plot until we learn what they've found, which could take months (even though the test will take nanoseconds).

I forget just which of the great Sci-Fi writers said it, but it has stuck with me as the basic frame of a successful SF storyline: Use just one absurd assumption/idea to move the plot, and build the rest of it with known science. Of course add character development and twists, etc. Sounds like a pretty sound formula to me.

The concept of a cotton ball at the speed of light has intrgued me since I was a child; let's see what happens...