Current doubler flux compression device for power amplification in vacuum

The current doubler flux compression (CDFC) is a proposed new device conceived to amplify power in vacuum to drive PRS in the 100 ns regime. The CDFC is cylindrical in shape, typically a few tens of cm axially and in diameter. High efficiencies in the production of Z-pinch generated X-rays are made possible by coupling the CDFC to pulsed power drivers of interest: in the multi-MJ stored energy, and pulse lengths between 300 ns and a few microseconds. This concept offers substantial economic advantages with respect to conventional 100 ns generators. The CDFC consists of a two-turn "transformer" vacuum convolute driving a cylindrical plasma shell forming the boundary between the primary and secondary cavities. The magnetic flux created by the first current turn enters the secondary cavity through a gate. When the gate is open the CDFC acts as a current doubler accelerating radially inwards the plasma shell to a stator. The magnetic field on the outer side of the plasma shell is twice as large as the magnetic field on the inner side of the shell. When the moving shell crosses the magnetic flux gate it closes the electrical circuit connecting, through a convolute, the secondary cavity and load. As the secondary cavity volume decreases the magnetic flux is forced into the load. Zero dimensional calculations for DECADE QUAD (DQ) and for a typical next generation machine are presented. Issues and advantages of the CDFC with respect to magnetic insulation, magnetic flux losses as result of RT instabilities are discussed.