BACKGROUND
The hunt for antimatter began in 1928 when Paul Dirac found an unexpected solution of anti-electron (positron) in his relativistic theory of electron. Energy is produced when matter meets antimatter, which could become the most efficient source of power if a sustainable, efficient means to harness anti-matter can be found. Antiprotons are created during high energy collisions of particles, and are too hot to handle, either annihilating or escaping before they can be cooled and gathered for research. Actually, they are fired out of the collisions with a ~GeV of energy that needs to be reduced to 10keV or less to be stored, which are then cooled down to a few Kelvin (fourteen orders of magnitude reduction in energy!) for antimatter production.

RESEARCH RESULTS
The Japanese researchers engineered qualitative improvements to the deceleration scheme, which decelerated and cooled the antiprotons from the AD with fairly large efficiency. First they added the RFQD to reduce the antiproton energy from 5.3MeV to 10-120 keV before the antiprotons were guided to the trap region. They also designed the MRT to further confine, slow and cool the antiprotons.
The four metre RFQD could decelerate approximately 30% antiprotons from the AD, which were guided to the MRT installed in a 3T superconducting solenoid via two thin foils into the MRT, a series of ring electrodes. In the MRT, the antiprotons were further cooled and decelerated via multiple collisions with preloaded electrons. The electrons in the MRT cool themselves via synchrotron radiation down to ~5K, the environmental temperature, and behave as non-neutral plasma, i.e., antiprotons were sympathetically cooled to a similar temperature through collisions with the electron plasma. 1.2 million antiprotons were stably stored in the MRT per one AD shot, 50-fold improvement in previous best records. After five shots, 5 million antiprotons remained in the trap.
The antiprotons so cooled were extracted as monoenergetic ultra slow antiproton beam of 10-500eV for the first time.

FUTURE WORK
Many believe that the explosion from which the universe emerged, the Big Bang, produced equals amounts of matter and antimatter, yet very little naturally occurring antimatter has been found. Being able to study antimatter would help explain why that asymmetry exists. This collaborative team is part of the ASACUSA (Atomic Spectroscopy and Collision Using Slow Antiprotons) project, one of three associated with the CERN Antiproton Decelerator in Geneva, that is seeking to create and understand antimatter to answer questions about the origins of our universe and also to apply antiprotons as a new probe of collision dynamics and nuclear structure study of exotic nuclei.

This paper was published in Physical Review Letters 94: 02340 (2005) on 21 January 2005.