Containment of Positrons in a Mirror Machine

Positrons emitted isotropically from a uniform volume source were contained in a static magnetic-mirror machine for a mean containment time greater than 10 sec, which corresponds to more than 10/sup 10/ cyclotron periods. This is of practical importance in various research fields such as studies of controlled fusion and studies of the Van Allen radiation belt. A description is given of the apparatus which consists of a magnetic-mirror machine having coaxial 60-in.-mean-diameter coils with 64 in. between coil centers, which are located adjacent to the cyclotron used to produce Ne/sup 13/. The present results agree with the fast filling'' experiment. They appear to agree with, and to extend, the conclusions of an experiment in which ionization currents created by 18-kev electrons in a mirror machine were measured. (B.O.G.)