Theoretical analysis of wire-guided ion beam transport

Summary Form only given, as follows. Ion beam transport using a current-carrying wire to provide an azimuthal confining magnetic field has been proposed for inertial confinement fusion applications. Several aspects of this transport scheme are being investigated theoretically to determine whether or not the scheme is viable. An important issue is how much of the injected ion beam current can be successfully transported. Propagating beam ions execute betatron-like oscillations around the wire and must have sufficient angular momentum to avoid collision with the wire. The fraction of the injected ion beam with sufficient angular momentum and with small enough radial excursion to match pellet dimensions is determined by the extraction ion diode focusing geometry, the wire size, and the current carried by the wire. A second issue is the length of the standoff or ballistic drift region, between the end of the guide wire and the target. The 1/r dependence of the guide magnetic field causes ion trajectories to bend inward sharply close to the wire, indicating that the standoff could be severely limited.<>