The ALPHA collaboration (Antihydrogen Laser Physics Apparatus) consists of scientists from a number scientific institutions whose goal it is to trap neutral antimatter in the form of antihydrogen in a magnetic trap and consecutively conduct experiments with the trapped antiatoms. The ultimate goal of this endeavour is to test the CPT theorem by comparing the atomic spectra of hydrogen and antihydrogen. The ALPHA collaboration consists of some former members of the ATHENA collaboration who was the first to produce large amounts of cold antihydrogen in 2002 as well as a number of new members. The challenges of these goals are many. Magnetic traps where the neutral atoms are trapped on their magnetic moment are notoriously weak; only atoms with kinetic energies equivalent to less than a kelvin may be trapped. The cold antihydrogen created first in 2002 by the ATHENA and the ATRAP collaborations was created by merging cold plasmas of positrons (antielectrons) and antiprotons. This method was very successful but seems to create antiatoms with too large kinetic energy to be trapped. Furthermore, to do laser spectroscopy on these antiatoms it is important that they are in their ground state, something which does not seem to be the case for the majority of the antiatoms created thus far. Antiprotons are received from CERN's Antiproton Decelerator and are 'mixed' with positrons from a specially-designed positron accumulator in a versatile Penning-Malmerg trap. This is surrounded by a superconducting octupole magnet to form a 'minimum-B' magnetic trap.
Member Institutions of the ALPHA Collaboration
- University of Aarhus, Denmark
- Auburn University, USA
- University of California Berkeley, USA
- University of Calgary, Canada
- University of Liverpool, U.K.
- University of Manitoba, Canada
- Nuclear Research Center Negev, Israel
- RIKEN, Japan
- Federal University of Rio de Janeiro, Brazil
- Swansea University, U.K.
- University of Tokyo, Japan
- TRIUMF, Canada
See also
The official page of the ALPHA collaboration ALPHA collaboration
