Design and Experimental Validation of Two Current Multiplier Configurations on a Microsecond MA Generator

Summary form only given. The current multiplier (CM) concept was proposed to increase the driver-to-load energy transfer efficiency. The suggested CM requires additional volumes with high self-inductance (magnetic flux extruders) connected through vacuum convolutes prior to the load and they extrude the magnetic flux toward the load magnifying the load current. We present the design criteria allowing to achieve high extruder self-inductance at low parasitic inductances added to generator and load in the modified circuit. Two configurations of this new device with one extruder are considered for GIT 12 microsecond MA generator having inductance of ~100 nH. The extruder inductance was either a large vacuum volume or a smaller volume with magnetic core. The discussed design procedure allowed to define optimum coreless and cored CM hardware configurations at conservative values of the AK gaps in CM vacuum lines (15-25 mm). The optimum coreless CM had 80 cm height and 170 cm diameter. Operating on a 8 nH inductive load in experimental tests on GIT 12 it allowed to increase the load current from 4.7 MA @ 1.7 mus without CM to ~6 MA @ 1.5 mus². A more compact cored CM configuration with 36 cm height and 85 cm diameter operating at a 4.6 nH inductive load allowed further load current increase up to ~8 MA @ 1.7 mus. Further experimental tests with a Ne gas-puff z-pinch load showed that the peak load current at ~1 mus was increased from 3.5 MA (no CM) to 5.2 MA and that the energy-delivered to load at implosion was increased from ~170 kJ to ~330 kJ. No considerable energy losses in the CM vacuum gaps and CM convolute were recorded. Therefore, it is experimentally confirmed that the proposed new device is applicable for improving characteristics of existing and future pulse-power generators.