Skipjack wrote:I love the Fusion Driven Rocket. It is foil liner compressed FRCs. It has a lot of thrust compared to other fusion engine designs and a Isp of 5000 is still plenty good. That said, if the Sheared Flow Stabilized Z- Pinch works, it would have this design beat in terms of Isp and thrust, which is quite crazy.
I am not an engineer Skipjack BS degree in Chemistry. But I remember from molecular kinetics that the higher the exhaust velocity (ISP is exhaust velocity divided by g) the higher the temperature. And ISP of 356,800 seconds (from the posted link for Z-pinch using D-He3) corresponds to a likely exhaust/plasma temperature well into the millions of degrees. Even if the plasma isn't coming in contact with the walls of the rocket at that temp. it (the plasma) would radiate EM intensely. Probably well into the UV range if not maybe soft X-rays; don't know. A thrust of 3.3×105 N corresponding with a stated power output of 3.3×1012W indicates a large throughput of such super-heated plasma. How much supplemental shielding/coolant would that take and how much would that add to the mass of our Z-pinch fusion rocket? The beauty of John Slough's design is that it masses at I believe around 100 tons. He obviously wanted something that could be launched into orbit by current rocket technology. Having said that there is no reason with Musk's reusable BFR on the horizon that Slough's design couldn't be scaled larger; nuclear pulse rockets actually get more efficient with larger size/mass. A larger collapse radius for the coils of Lithium would produced longer acceleration times/faster velocity/higher compression temperature/pressure insuring more complete fusion for instance. That might increase ISP/thrust considerably; also it seems that Slough's approach is more doable with current technology.