Experiments and theoretical calculation of explosive-driven shock wave ferromagnetic generators

Two types of ferromagnetic generators were designed. For one type, a cylinder Nd₂Fe₁₄B rare-earth permanent magnet was used as working body, and a plane shock wave forms the detonation of the explosives moved in the cylinder along the direction of its axis. For the other type, a ring Nd₂ Fe₁₄B magnet was charged with high energy explosive in the center hole, and the explosives were initiated with two ends at the same time. The initial magnetic flux distribution of the Nd₂Fe₁₄B magnet was simulated by the Maxwell 3D code of the electromagnetic analysis software. The calculating method of the electromotive force from the ferromagnetic generators was given. The detonation tests of generators were carried out. The output current and voltage of generators were measured. The shock wave velocity in Nd₂Fe₁₄B magnet was measured. The results show that the ferromagnetic generators designed are capable of producing a high current pulse of up to 1212 A, with the width of 78.3μs, and the electromotive force obtained is about 67 V/turn.