As simple as it sounds, making antimatter is NOTHING close to simple...
First, you need to make anti-protons. Then you need to make positrons, and bind them together - one single atom at a time.
With today’s technology, making a teaspoon of antimatter will bankrupt ANY nation. So, in the book, it’s not possible for the LHC to produce amount that is visible to the naked eye.
Consider this, making ONE gram of antimatter will cost 100 QUADRILLION dollars and the atom smasher need to operate for 100 BILLION years! [Physics of the Impossible – MK]
The Tevatron (Fermi lab), particle collider in Chicago. USA. The largest particle collider before the LHC.
Finding them in nature.
So, one might just say, “hey, if it’s so hard to make antimatter on earth, why don’t we look for it in the universe?”
Again, not as easy as it seems.
Suppose there’s a star that is made of entirely antimatter somewhere in this galaxy we stay, the star’s surface must be a VERY happening place as explosions happens ALL the time! Loads of gamma rays will be emitted and we can detect it with our detectors with ease.
So far, we have scanned the universe in gamma ray spectrum we see no signs of that.