On the structure of rotational discontinuities with large phase angles

Abstract

Using hybrid simulations (particle ions and electron fluid) we have investigated the stability of rotational discontinuities. A density increase builds up at the position of the rotational discontinuity. The final density structure of the rotational discontinuity develops independently of the initial phase angle φ and of the half width D. Only minor differences occur for different senses of rotation, i.e. for a rotational discontinuity exhibiting an ion sense or an electron sense of rotation, respectively. However the structure of the magnetic field, B, strongly depends on the phase as shown by simulations of rotational discontinuities with 270° phase angle. Rotational discontinutiies with 270° phase develop independently of the initial sense of rotation into structures with 90°-rotation.