Advances in Antihydrogen Physics

  title={Advances in Antihydrogen Physics},
  author={M Charlton and D.P. van der Werf},
  journal={Science Progress},
  pages={34 - 62}
The creation of cold antihydrogen atoms by the controlled combination of positrons and antiprotons has opened up a new window on fundamental physics. More recently, techniques have been developed that allow some antihydrogen atoms to be created at low enough kinetic energies that they can be held inside magnetic minimum neutral atom traps. With confinement times of many minutes possible, it has become feasible to perform experiments to probe the properties of the antiatom for the first time. We… Expand
6 Citations
On the formation of trappable antihydrogen
The formation of antihydrogen atoms from antiprotons injected into a positron plasma is simulated, focussing on the fraction that fulfil the conditions necessary for confinement of anti-atoms in aExpand
Low-energy l-mixing collisions of excited positronium with protons and antiprotons
We investigate l-mixing processes in collisions of excited positronium (Ps) atoms with protons in the range of the principal quantum number n of the Ps atom between 4 and 8. We show first thatExpand
Recent progress in the description of positron scattering from atoms using the Convergent Close-Coupling Theory
Much progress in the theory of positron scattering on atoms has been made in the ten years since the review of Surko, Gribakin and Buckman [J. Phys. B 38, R57 (2005)]. We review this progress forExpand
Convergent close-coupling approach to positron scattering on He+
Abstract A close-coupling method is used to generate electron-loss and total scattering cross sections for the first three partial waves with both a single-centre and two-centre expansion of theExpand


A source of antihydrogen for in-flight hyperfine spectroscopy
This work reports the development of an antihydrogen source using a cusp trap for in-flight spectroscopy, a major step towards precision spectroscopic of the ground-state hyperfine splitting of antiHydrogen using Rabi-like beam spectroscope. Expand
The route to ultra-low energy antihydrogen
We begin by discussing the concept and field of antimatter and how quantum mechanics and relativity led to its discovery. We describe how neutral antimatter, in the form of antihydrogen, is a naturalExpand
Dynamics of antiproton cooling in a positron plasma during antihydrogen formation
Abstract We demonstrate cooling of 10 4 antiprotons in a dense, cold plasma of ∼10 8 positrons, confined in a nested cylindrical Penning trap at about 15 K. The time evolution of the cooling processExpand
Stacking of cold antiprotons
Abstract The stacking of cold antiprotons is currently the only way to accumulate the large numbers of the cold antiprotons that are needed for low energy experiments. Both the largest possibleExpand
The ATHENA antihydrogen apparatus
Abstract The ATHENA apparatus that recently produced and detected the first cold antihydrogen atoms is described. Its main features, which are described herein, are: an external positron accumulator,Expand
Antihydrogen formation dynamics in a multipolar neutral anti-atom trap
Abstract Antihydrogen production in a neutral atom trap formed by an octupole-based magnetic field minimum is demonstrated using field-ionization of weakly bound anti-atoms. Using our uniqueExpand
Atomic processes in antihydrogen experiments: a theoretical and computational perspective
One possible route for a precision test of the CPT theorem is to perform spectroscopic measurements on the antihydrogen atom and compare the results with those from hydrogen. We present a review ofExpand
A novel cooling scheme for antiprotons
We propose a novel technique which uses laser-cooled negative osmium ions for sympathetic cooling of antiprotons. Temperatures down to the sub-millikelvin range might be achievable. These antiprotonsExpand
Spatial distribution of cold antihydrogen formation.
Experimental evidence is presented that the spatial distribution of the emerging antihydrogen atoms is independent of the positron temperature and axially enhanced, indicating thatAntihydrogen is formed before the antiprotons are in thermal equilibrium with the positrons in a nested Penning trap. Expand
Production and detection of cold antihydrogen atoms
This work demonstrates the production of antihydrogen atoms at very low energy by mixing trapped antiprotons and positrons in a cryogenic environment and detects the neutral anti-atoms directly when they escape the trap and annihilate, producing a characteristic signature in an imaging particle detector. Expand