Antiproton Decelerator

The AD decelerates the resultant antiprotons to an energy of 5.3 MeV, which are then ejected to one of several connected experiments.

The major goals of experiments at AD are to spectroscopically observe the antihydrogen and to study the effects of gravity on antimatter.

Though each experiment at AD has varied aims ranging from testing antimatter for cancer therapy to CPT symmetry and antigravity research.

During the end stages of LEAR, the physics community involved in those antimatter experiments wanted to continue their studies with the slow antiprotons.

[4] In 1996, the CERN Council asked the Proton Synchrotron (PS) division to look into the possibility of generating slow antiproton beams.

[3] The iridium rod embedded in graphite and enclosed by a sealed water-cooled titanium case remains intact.

A magnetic bi-conical aluminum horn-type lens collects the antiprotons emerging from the target.

[3][7] ELENA (Extra Low ENergy Antiproton) is a 30 m hexagonal storage ring situated inside the AD complex.

Later ATRAP members pioneered accurate hydrogen spectroscopy and observed the first hot antihydrogen atoms.

[18][19] It also measures atomic and nuclear cross-sections of antiprotons on various targets at extremely low energies.

Although the experiment ended in 2013, further research and validation still continue, owing to the long procedures of bringing in novel medical treatments.

Using this pattern, it can be measured how many atoms of different velocities are vertically displaced due to gravity during n their horizontal flight.

[24] GBAR (Gravitational Behaviour of Anti hydrogen at Rest), AD-7 experiment, is a multinational collaboration at the Antiproton Decelerator of CERN.

The GBAR project aims to measure the free-fall acceleration of ultra-cold neutral anti-hydrogen atoms in the terrestrial gravitational field.

[25] BASE (Baryon Antibaryon Symmetry Experiment), AD-8, is a multinational collaboration at the Antiproton Decelerator of CERN.

The goal of the Japanese/German BASE collaboration[26] are high-precision investigations of the fundamental properties of the antiproton, namely the charge-to-mass ratio and the magnetic moment.

By measuring the spin flip rate as a function of the frequency of an externally applied magnetic-drive, a resonance curve is obtained.

PUMA's experimental goals require about one billion trapped antiprotons made by AD and ELENA to be transported to the ISOLDE-nuclear physics facility at CERN, which will supply the exotic nuclei.

CERN AD with the ALPHA, ASACUSA and ATRAP experiments.
ELENA ring
Members of ACE collaboration at experimental setup
ALPHA experiment
GBAR (Gravitational Behaviour of Anti hydrogen at Rest) experiment