The CERN Small Giant: the Antimatter Factory

19 DECEMBER, 2023 | By François Butin, Giulia Romagnoli, Davide

Did you know??

That the AD facility is some kind of mini-CERN in itself?

The AD complex includes no less than:

• 2 synchrotrons: AD and ELENA, the smallest of the CERN synchrotrons, only 30 m in circumference, about 1/1000 of LHC!
• 1 ion source, producing H⁺ or H^– ions, so that ELENA can be commissioned even when AD is not in operation. Actually, the H^– beams from ELENA are also used by experiments to do physics!
• 1 electron LINAC, delivering 9 MeV electrons on a tungsten target to produce positrons for the GBAR experiment.
• 1 production target, where the 26 GeV protons from the PS hit an iridium rod to produce the antiprotons.
• 100 m of transfer lines, mostly using electrostatic optics elements instead of more classical magnets, as the beam kinetic energy is as slow as 100 keV at ELENA ejection!
• 7 experiments using the antiprotons beams to do world class physics. Actually, AD is the only place on earth where anti-hydrogen is produced!

Did you know???

The AD ring was born in the 2000s on the ashes of the Antiproton Collector (AC) ring in bldg. 193?

The AD ring is 182 m long, and it is circulating anti-protons coming from the target area where the protons from the PS hit the iridium target and generate anti-protons. The AD ring looks nearly as old as the PS ring if somebody is walking by. The AD ring was built following a modern concept of “re-cycling and re-using” with the pieces of various old machines, including the AC machine, which was built in the late eighties and even from the Initial Cooling Experiments (ICE) from the late seventies!

Did you know??

That the so called “Antimatter Factory” is producing antiprotons in different ways and flavors?

I believe all of us, at least once, looking at the name on the front door of AD building, thought of entering a Chocolate Factory instead of an antimatter one. In a sense, this is not so wrong…

At the end, even if the AD ring is physically built on French soil, we are in Geneva! Furthermore, when going in a guided tour looking at the top of the ELENA ring, the CERN guide will always tell you, the aluminum paper is not there to wrap chocolate 😊

Furthermore, with all the different experiments and extraction lines inside the building, one can really compare the anti-protons production to chocolate manufacture lines each of them preparing, cooking, mixing the (anti)chocolate in different ways still producing an amazing final product.

The majority of experiments in the hall start from the same base ingredient: the anti-protons from the ELENA ring. Then they add anti-electrons by different cooking and mixing ways to form, with their own recipe, the anti-hydrogen atoms and study (or taste) them following different paths.