"In order to direct the plasma resulting from the explosion towards the rear of the vehicle a magnetic nozzle is utilized. The MMO team utilized particle trajectory (developed at the University of Washington) and MHD (MACH2) based analysis to investigate nozzle characteristics and establish a baseline suitable to the MMO vehicle concept. The final baseline nozzle, produces 1,870kN of thrust,
16,000 seconds of specific impulse and a nozzle efficiency of 87.1% at a yield of 340GJ per implosion.
It consists of 5 coils distributed over 11 meters with coils preferentially clumped near the axis, each carrying 10 MA of current. The total array mass is approximately 200 metric tons.
The power supply for the Z-pinch implosion should provide a current evolution with approximately a
unimportant since the implosion interrupts the current. The electrical power requirements for the magnetic nozzle are determined by the final nozzle design (magnetic field and coil locations). The power requirements of the two systems are sufficiently different that individual power supplies should be tailored to each system.
The high currents and short rise times required by the implosion can be generated by charging a capacitor bank in parallel to a lower voltage and then using switches to connect the capacitor in series. This configuration is called a Marx bank. The Marx bank
170 kV. The choice was driven by easily available capacitors at the rated voltage and capacitance. It is envisioned that the switches will be high voltage gap switches with low inductance.
The charge supply is isolated from the capacitors through two 250 ? resistors for each capacitor. The energy required for each implosion is CV2 /2 or 72 MJ. At a pulse rate of 1 Hz, the power requirement is 72 MW."