We know a lot about theory, but is antimatter real? Speaking with facts, the existence of the antiproton was experimentally confirmed in 1955 by two physicists, E. Segre and O. Chamberlain of the University of California. In 1995, CERN managed to bring into existence nine antihydrogen atoms, and in 2002 they announced that they had created the world's first "cold" antihydrogen. Just recently, on April 26, 2011, they announced that they had trapped 309 antihydrogen atoms, some for as long as 1,000 seconds. Therefore, antimatter experimentation has proven its existence beyond any doubt.
Generation of Antiparticles
Antiparticles are mainly generated during the collision of subatomic particles. Particles such as protons hit a target which is made of metal and release huge amounts of energy. This energy combined with high temperature and pressure, creates short lived antiprotons which instantly annihilate when they meet their proton-match.
The well-known Antiproton Decelerator (or AD) in CERN produces low energy antiprotons that can be used for the synthesis of antihydrogen atoms. More specifically, almost 10 trillion protons hit the target each minute, producing about 10 million antiprotons. Some of them enter the ring of the vacuum pipe where strong electromagnetic fields bend the trajectory of the antiprotons and decelerate them. As soon as their speed reaches 10% of the speed of light, they are ejected from the ring.