Electromagnetic Implosion of Spherical Liner

We have magnetically driven a tapered-thickness spherical aluminum shell implosion with a 12.5 MA axial discharge. The initially 4 cm radius, 0.1 to 0.2 cm thick, ±45° latitude shell was imploded along conical electrodes. The implosion time was approximately 15 μsec. Radiography indicated substantial agreement with 2D-MHD calculations. Such calculations for this experiment predict final inner-surface implosion velocity of 2.5 to 3 cm/μsec, peak pressure of 56 Mbar, and peak density of 16.8 g/cm³ (>6 times solid density). The principal experimental result is a demonstration of the feasibility of electromagnetic-driven spherical liner implosions in the cm/μsec regime.