Collisionless mirror mode trapping

We investigate trapping of mirror modes in a magnetic slab. This model is a simplification of a real situation in front of the magnetopause where mirr or waves may become trapped in a region close to the magnetopause for tange ntial discontinuity conditions and an unidentified (hypothetical) boundary deeper in the sheath which we, for simplicity, assume to be another tangent ial discontinuity. Such magnetic slabs may trap mirror modes selecting a pa rticular perpendicular wave lengths which follows from a quantization condi tion on the perpendicular wavenumber.