Abstract
An antihydrogen (H-) atom-a positron (e+) in orbit about an antiproton (p-)-is the simplest atom made entirely of antimatter. Producing H- atoms that are cold enough to be trapped for precise laser spectroscopy, to compare antihydrogen and hydrogen, is a goal that has been pursued for many years. A prequel to this review summarized the techniques for accumulating cold p- and e+ that opened the way to slow H- production, along with crucial devices like the nested Penning trap that was developed to bring the p- and e+ together. Several exciting years have seen the first production, observations and studies of slow H- atoms-so far by two different methods. The demonstrations of e+ cooling of p- in a nested Penning trap led to observations of slow H- atoms produced in this way (method I) using two detection techniques. Field ionization detection of H- produced by method I makes it possible to go beyond the simple counting of H- atoms via charge exchange collisions-a method that seems to naturally produce H- atoms with essentially the low energy distribution of the p- from which they form.
| Original language | English (US) |
|---|---|
| Title of host publication | Advances in Atomic, Molecular and Optical Physics |
| Editors | Benjamin Bederson, Herbert Walther |
| Pages | 155-217 |
| Number of pages | 63 |
| DOIs | |
| State | Published - 2005 |
Publication series
| Name | Advances in Atomic, Molecular and Optical Physics |
|---|---|
| Volume | 50 |
| ISSN (Print) | 1049-250X |
Funding
It has been and remains an honor and pleasuret o lead the ATRAP collaborationa,s it was the TRAP collaborationfr om which it grew. The ATRAP team (table I) is very dedicateda nd skilled, as is neededf or such demandinge xperimentsS. pecial thanks to ATRAP membersf or their commentos n this review-especiallyto A. Speck, C. Storry, E.A. Hessels, W. Oelert and J. Walz. Thanks for helpful discussionsa nd comments to E.A.G. Armour, J. Fajans, P. Froelich, S. Jonsell, T. O'Neil, and B. Zygelman. I am gratefutl o CERN, its PS Division and the AD teamf or buildingt he AntiprotonD eceleratort-h e only facility in the world that is capableo f delivering5 .3 MeV antiprotonst o us. We profited from the help and personael ncouragemeonft the AD staff, the SPSC, the researchd irectors and the directorsg eneral. This work was supportedb y the NSF and AFOSR of the US, the BMBF, MPG and FZ-J of Germany,a nd the NSERC, CRC, CFI and OIT of Canada. Finally I am grateful to the Harvard University and its physics departmenfot r their good naturedw ay of accommodatintog a department chair who madew eeklyt ripsto CERN to do antihydrogerne searcha, nd to the wonderfuls taff, assistantr,e searchg roup and family that made it all possible.
ASJC Scopus subject areas
- Statistical and Nonlinear Physics
- Electronic, Optical and Magnetic Materials