Uniform-density, spherical electron focus

An equilibrium electron distribution is exhibited which forms a uniform ele ctron density focus within a spherical system. Such a focus may be used to form a spherical, harmonic well for ion focusing as previously discussed. A self-consistent density and space-charge potential are calculated and the optimum focus radius is determined. Nonideal effects on electron and ion mo tion in the resulting electrostatic well are briefly discussed and strategi es for their minimization are derived. (C) 1999 American Institute of Physi cs. [S1070-664X(99)00912-X].