Small Helical Magnetic Flux Compression Generators: Experiments and Analysis

This paper presents the design of, and tests with, this helical flux-compression generator. The generator had an initial inductance of 23 muH and was operated into a load of 0.2 muH. The generator is charged with 0.27 kg of high-explosives (PBXN-5). Various types of diagnostics were used to monitor the operation of the generator, including current probes, optical fibres, and piezo gauges. With seed currents of 5.7 and 11.2 kA, final currents of 269 and 436 kA were obtained, corresponding to current amplification factors of 47 and 39. The peak of the current was reached about 30 mus after the time of crowbar. The two generators showed only small losses in terms of 2pi-clocking. Using signals from optical fibres, the deflection angle of the armature could be determined to be 10deg in good agreement with hydrodynamic simulations of the detonation process and the detonation velocity to be 8.7 km/s in agreement with the tabulated value.