Particle behaviour in independently established rotating E- and B-fields

In a configuration of rotating, crossed E- and B-fields which are independently established, the behaviour of charged particles is investigated. A resonance condition is found, even in the presence of a stationary B_z-field parallel to the axis of rotation. Particles travel predominantly in this direction. This combination of fields can be made to act either as a velocity discriminator, accelerator, reflector or injector. A numerical example of the last case is given with the following typical values: Rotating field strengths of 50 V/cm and 10³ G at a frequency of rotation of 10⁵ H_z; stationary field-strength B_z of 10⁴ G. When starting with zero energy the particle gains 600 eV after travelling a distance of 50 cm.