Non-adiabatic magnetic traps

A novel method of injection into a mirror machine, reported recently by Sinelnikov et al. , is analysed in detail by numerical and perturbation solutions of the equations of motion of a single particle. The principle of the method is to inject particles through one of the mirrors, along the lines of force. The magnetic field in the centre of the machine has a small, spatially periodic radial component which, for certain initial conditions, causes a resonant interchange of energy from the longitudinal to the transverse component of the particle's velocity. This results in reflection of the particles by the end mirror, and by suitable adjustment of the mirrors the particles may be contained inside the machine for an appreciable number of transits. The possibility of increasing the accumulation of particles by combining this method of injection with molecular-ion dissociation is also discussed.