Speaker
Description
Many of the instabilities that are common to magnetically confined ion-electron plasmas are expected to be suppressed in electron-positron "pair" plasmas. The goal of APEX (A Positron Electron eXperiment) is to create and confine a pair plasma by combining separate non-neutral plasmas of electrons and positrons. Challenges associated with this task include (i) the construction of a trap that can simultaneously hold the oppositely charged leptons, and (ii) the accumulation and injection of sufficiently many positrons to produce a neutral plasma. A compact, levitating dipole trap (LDT) has been built to magnetically confine pair plasmas, and long levitation (> 2 hr) and stable trapping of pure electron plasmas (> 2 s) have already been achieved. In parallel to the LDT development, a lossless E×B-drift technique was recently adapted to inject bunches of positrons into a supported dipole trap. The pulsed beam was used to study transport in the inhomogeneous magnetic field and to test schemes for merging collections of electrons and positrons.
