ALPHA 1 (2005– 2012)

Physics: First trapped antihydrogen. First quantum transitions (hyperfine).

Hardware: Octupole based minimum-B field Ioffe-Prittchard trap for neutral atoms superposed on Penning-Malmberg trap for antihydrogen synthesis.

ALPHA 2 (2012 - present)

Physics: First laser spectroscopy. First laser-cooling.

Hardware: Catching trap introduced to split functionality away from antihydrogen region to improve mechanical access (for e.g. lasers).

ALPHA Beamline (2018 - present)

A separate system that connects ALPHA 2/3, ALPHA-g and the Positron Accumulator to allow the accumulator to feed positrons to both ALPHA 2/3 and ALPHA-g as well as allow for antiprotons to be transported to ALPHA-g.

ALPHA 3 (2021 - present)

Aim: Hydrogen precision in antihydrogen spectroscopy. First observation of photons from antihydrogen. Improved antihydrogen trapping & stacking. Observation of additional optical transitions (e.g. 4s->2s) in antihydrogen

Hardware: Upgrade with fluorescence detection for 121nm light as well as visible wavelengths. Will also include detection of 313nm light for laser-cooling and magnetometry with Be+.

ALPHA-g (2021 - present)

Aim: 10% precision on measurement of the inertial to gravitational mass of antihydrogen. 

Hardware: New vertical system of about double the size of ALPHA 2/3. Double Penning-Malmber trap and neutral atom traps. Highly improved precision in construction of magnets to improve (a) homogeneity of fields and (b) knowledge of fields. Super-conductor mass reduced to limit persistent current issues.