Newly Designed Destructive Magnetic Coils for Mega-Gauss Fields at ISSP

Electro-magnetic flux compression (EMFC) is one of the most powerful methods to generate mega-gauss magnetic fields. The EMFC facility at ISSP has attained the world record for indoor generation of magnetic fields. We have recently implemented successful improvements to generate a higher field with less energy injection and with more simplified coil preparation processes. We have changed the structure and the materials of the primary coil. We have tested the new coil system and succeeded in generating fields up to 350 T with 1 MJ, 470 T with 2 MJ and 520 T with 3 MJ. Hence, electro-magnetic energy transfer efficiency has been increased a great deal. The liner implosive motion was much improved with good cylindrical symmetry. A simple calculation has given insight into the relations between the current density distribution of a primary coil and the shape of the liner during the process of the implosion.