the name of the machine where antimatter is tested is called the antielectron accelerator.

The statement in the title is not correct: the machine where antimatter is commonly produced and tested at CERN is not called an “antielectron accelerator.”

What these machines are actually called

• The main dedicated antimatter facility at CERN is the Antiproton Decelerator (AD) , a storage ring that slows down antiprotons so experiments can create and study antihydrogen and other antimatter systems.

• An additional ring called ELENA (Extra Low ENergy Antiproton) further reduces the energy of antiprotons coming from the AD to make precision experiments easier.

• Antimatter used in these experiments is typically made by firing high‑energy protons from a synchrotron (such as CERN’s Proton Synchrotron) into a metal target, producing secondary particles that include antiprotons , which are then captured and decelerated.

What about “antielectrons”?

• The correct name for an “antielectron” is a positron , and there are positron sources and positron beams in physics, but there is no standard or famous machine known in the community as “the antielectron accelerator” used as the generic antimatter‑testing machine.

• Large facilities that study antimatter (like CERN’s AD complex) handle multiple antiparticles and antiatoms, and are usually referred to by their official names (AD, ELENA, specific experiments like ALPHA or AEgIS), not by a generic “antielectron accelerator” label.

If this is for a “Quick Scoop” style post

• A more accurate, catchy line could be:
  • “The machine where scientists study antimatter at CERN is called the Antiproton Decelerator , part of the lab’s so‑called ‘antimatter factory.’”

• You could then briefly note that antimatter experiments there include trapping antihydrogen and testing whether antimatter falls the same way as ordinary matter in Earth’s gravity.

Information gathered from public forums or data available on the internet and portrayed here.