Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

The Tevatron is a proton-antiproton collider; it collides a beam of protons against a beam of antiproton.

I can understand how we obtain the protons, but for the antiprotons ? How are they produced ?

share|cite|improve this question
up vote 8 down vote accepted

The only way to produce antiprotons would be to collide some particles together and then filter out just the antiprotons (as there are no stable particles that we know of containing antiprotons).

Fermilab produces the protons and antiprotons in a couple of stages. It starts with negatively ionised hydrogen and accelerates it using a Cockcroft-Walton accelerator to 750keV, by basically cycling the ions through a potential difference multiple times. These ions are then fed into a linear accelerator that uses an oscillating electroc field to accelerate them to 400 MeV. The electrons are then stripped from the ions using a carbon foil, ending up with 400MeV protons. These then go into the Booster which accelerates them to 8GeV.

This is the proton production stage and following this, the 8GeV protons are directed to the first ring of the Tevatron (the Main Injector) where they can be accelerated up to 150GeV. Once the protons reach 120GeV, some are collided with a nickel target, producing a shower of particles. The antiprotons are filtered and directed back to the Main Injector, which accelerates both the protons and antiprotons to 150GeV. The two beams are now fed into the main accelerator (the Tevatron) which accelerates them to 1TeV and crosses them at the detector site, producing the shower of particles that is detected and analysed :)


share|cite|improve this answer
Very nice answer, thanks ! – Cedric H. Nov 4 '10 at 18:07
Thanks Cedric, and you're welcome :) – Flaviu Cipcigan Nov 4 '10 at 19:25
It's worth noting that all beams of unstable particles (muons, pions, neutrons, etc...) are produced colliding a beam of stable stuff with a target and selecting the desired products from the resulting spray. (We'll treat anti-protons as "unstable" for these purposes 'cause you can't easily hold them...) – dmckee Jan 15 '11 at 19:16
@dmckee almost all :) for radioactive ions beams a good method (ISOL) consists in stopping the beam in a thick target and restart the acceleration of the required particles from scratch. For an introduction: – DarioP May 28 '15 at 15:36

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.