Successful production of non-neutral electron plasma of high density in the multi-ring trap

Abstract

Accumulation of electrons to form dense electron plasma in a modified Malmberg–Penning trap, a multi-ring trap (MRT), is investigated. Under ultra-high vacuum conditions, the electron plasma is confined radially using a 5 T magnetic field and axially by using a harmonic potential well of depth 1000 V. Electron plasma of density higher than 1×1011 cm−3 was confined in the MRT, and the number of trapped electrons can be controlled by changing the trap depth and the trap length. A longitudinal plasma temperature of 0.1 eV was measured, and the cyclotron cooling time was found to scale as 4.5/B 2 (T).