There are a lot of key differences. Bussard IEC can be characterized by recirculation of electrons, virtual cathode, "wiffleball" magnetic compression. VASIMR can be characterized by helicon antenna, single phase instead of multiphase.
Some people do not even know the difference between a carrot and a screwdriver.
Please, take a closer look. The concepts have key differences. Bussard IEC has recirculation of electrons, virtual cathode. VASIMR is single phase instead of multiphase.
Nuclear propulsion will open vast horizons to the future of mankind. I think the best option will be fusion-powered plasma turbines. http://youtu.be/ro5-QYqqxzM
The Sun is not doughnut-shaped. The ITER fusion machine is conceptually flawed; the drawbacks are numerous: confinement time, plasma temperature, energy consumption, tritium breed, and there on. It is a lame that mainstream scientists think they are so smarter, but are unable to understand that electrostatic fusion machines are conceptually much better, much more energy-efficient and can be developed with much less money and in less time. http://youtu.be/ro5-QYqqxzM