Multistage Magnetic Compression of Highly Ionized Plasma

The mean energy of the charged particles of a plasma which is confined in a magnetic field may be increased by increasing the magnitude of the magnetic field in a time which is short with respect to the ion relaxation time (magnetic compression). It is shown that the necessary stored energy can be reduced and the efficiency greatly increased if the magnetic compression is performed in several stages, such that the plasma is compressed and transferred to successively smaller volumes. The predicted transfer behavior has been confirmed by studying the plasma movement in a three-stage system. In the course of the investigation a plasma source has been developed which provides bursts of plasma of 1016 to 1018 ions with an average velocity of the order of 107 cm/sec.