Greetings and antimatter question

[alexbib]

Greetings everyone, I'm new to these forums and would first like to salute all of you.

Also, I've got a few little questions about matter/antimatter interaction and was wandering if anybody could help me out.

What are the conditions that must be met for a particle and an antiparticle to annihilate?

Say I shoot an antiproton into gazeous helium, would it be able to annihilate with a proton that is bound in an He nucleous? What if you make it collide with dense, solid material?

Also, could an antihydrogen atom annihilate directly with an hydrogen atom? What about with a normal matter atom of another kind (Cu for example)?

Alex

 

[chroot]

Originally posted by alexbib
Greetings everyone, I'm new to these forums and would first like to salute all of you.

Welcome!

What are the conditions that must be met for a particle and an antiparticle to annihilate?

They must collide.

Say I shoot an antiproton into gazeous helium, would it be able to annihilate with a proton that is bound in an He nucleous? What if you make it collide with dense, solid material?

Yes, it will be attracted to the nucleus both via electromagnetism and via the strong force, and will annihiliate with the first proton encountered.

Also, could an antihydrogen atom annihilate directly with an hydrogen atom? What about with a normal matter atom of another kind (Cu for example)?

Yes, in both cases.

- Warren

 

[alexbib]

Ok, thanks for answers mate!

 

[selfAdjoint]

Back in the Renaissance alchemists were searching for the universal solvent, a substance that would dissolve everything. Practical minded folks asked them "What would you keep it in?"

Physicists who make antimatter have this problem too. How can they prevent their precious and expensive antiprotons from contacting some normal matter and annihilating? They use magnetic bottles and keep the protons in ionized (charged) form so they can be confined by the magnetism. I think there are maybe a few ounces of antiprotons saved in labs over all the earth.