Extraction of small-diameter beams from single-component plasmas

A nondestructive technique is described to extract small-diameter beams from single-component plasmas confined in a Penning-Malmberg trap following radial compression using a rotating electric field. Pulsed beams with Gaussian radial profiles and diameters as small as 50 mu m are extracted from electron plasmas initially 2 mm in diameter. A simple theory for the beam diameter predicts 4 lambda(D) (full width to 1/e), where lambda(D) is the Debye length, in good agreement with experimental measurements on electron plasmas. Applications and extensions of this technique to create bright, finely focused beams of positrons and other scarce particles are discussed. (c) 2007 American Institute of Physics.