Deceleration in an anticyclotron as a means of producing very low energy antiprotons

Abstract

A lively interest is apparent in physics with very low energy antiprotons (from a few tens of keV down to thermal or kelvin energies). The first step in such endeavours is to find an efficient deceleration process from the currently lowest energy beams available from LEAR (2 MeV), to energies at which collection in a trap of reasonably small dimensions can be achieved. The present work describes encouraging results on the possibility of modifying the KfK "cyclotron trap" to do this at very low cost. The antiprotons are decelerated by degradation in a low pressure gas and extracted by a pulsed electric field in one of the axial boreholes through the magnet. Computer simulations suggest that the extraction process can be at least 75% efficient with a 300 V/cm extraction field, and that overall efficiencies could be as high as 20-30%. Moreover, experience from a series of antiproton capture experiments done at the magnet centre has shown that such simulations can be very accurate. Experimental confirmation of the new features is nevertheless essential. We also briefly described a possible physics program with this device, including its possible incorporation into the antiproton gravity experiment, PS200. © 1989.