So, you want a nice easy source of antimatter? Not a problem it seems. In an article that will be published in the August 20th edition of Astrophysical Journal Letters a team from Europe is going to announce that they have found a significant number of antiprotons trapped in the Earths magnetic field.
There has been a theory that predicts that high energy particles, commonly called Cosmic Rays, hit the upper atmosphere and hammer apart atoms there. Depending on the energy they can cause what is called Paired Production. This is where the impact energy of the Comic Ray particle is high enough to cause a nucleus to split into two protons, one with a positive charge and one with a negative charge. The negatively charged proton is antimatter.
Most of the time these particles fall into each other right away and destroy each other in a brief flash. But in the magnetosphere the field lines tend to separate the particles and they don’t immediately annihilate in a mass energy conversion.
This theory was tested, and apparently proved right by the PAMELA experiment. PAMELA stands for Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics. It was launched in 2006 from the Baikonur Cosmodrome.
It gathered data for 850 days and now that data has been scrupulously analyzed. The most abundant area of antiprotons is in the South Atlantic Anomaly. That is at once the spot where the Van Allen Radiation belts come closest to the Earth and the weakest place in our magnetic field.
These conditions make it ideal for the production and capture of antiprotons by CR paired production. And there are quite a lot of them there, at least relative to the rest of the solar system is concerned. In fact the level of antiprotons detected is 300% of what we detect in space.
Now what good does it do us to know this? Well it confirms a theory, so that is good news for science (even though disproving a theory is also good news for science), but it also provides us with a source of antimatter. Antimatter, in any form is pretty potent stuff. A single proton antiproton reaction produces between 4.4 and 6.3 MeV, which is about about a trillionth of a joule of energy (Thanks to RoadbedGuy for fixing my math mistake!) But even at that you have to recognize that it is coming from two particles that we can not even image. It is a big bang that comes in a little package.
We have managed to make and capture a few antiprotons. Making them we’ve been able to do in super-colliders since the late 1960’s. The trick is capturing them before they destroy themselves against all the other matter around.
That is a new trick we’ve mastered just the last couple of years. The speed involved is incredible and more often than not we fail. Even knowing how to do it the numbers of antiprotons created and captured is below 100.
So, if we could get out there and use our capture methods to Hoover up these micro particles they could be used for a very, very efficient propulsion system. Of course if you are a glass half empty kind of person you could assume they will be used for super effective explosives. Ya pays your money and you takes your chances.
What is clear is that our best source for antimatter in the near future is going to be a natural and renewable one, out there in the South Atlantic Anomaly. Who knew that antimatter was a renewable resource?
The floor is yours.