The general conditions for particle confinement are derived for an axisymmetric system and specialized to a general class of vortex-type field-reversed magnetic configurations. The criteria for closed-field and open-field confinements are obtained, including both the lower and upper bounds of P/sub theta//q where q is the charge of the particle. The constraint on P/sub theta//q represents a necessary condition for particle confinement. In certain limits, the commonly used criterion for Hamiltonian, H < ..omega../sub 0/P/sub theta/, where ..omega../sub 0/ identical with qB/sub 0//mc, is deduced from a more general form as a special case. In addition, a new criterion, -B/sub 0/R/sub w//sup 2//2c < P/sub theta//q < 0, where R/sub w/ = wall radius, and B/sub 0/ = vacuum field, is found necessary to be imposed, which reduces the confined region in (E, P/sub theta) space. These results can be applied to calculations for Field-Reversed Mirrors and Field-Reversed Theta Pinches
