Fusion propulsion with fuels that release few neutrons, the subject of two Defense Intelligence Reference Documents of 1 November 2010 in PURSUE Release 06, DOW-UAP-D145 and DOW-UAP-D146 (DIRDs). Both print the same title with no part number; the release calls them I and II, and their author labels differ.
D145 is a tutorial and survey. Hydrogen-lithium-6 and hydrogen-boron-11, it says, need Lawson criteria of 0.005 and 0.014 against 34 for deuterium-tritium; Bussard’s proposals appear the best developed; ignition is the hurdle every fusion design faces; and antimatter engines are the more promising technology. Its worked example has a 14-ton system take about 127 years to reach Proxima Centauri. An appendix notes Heim quantum theory, saying there are few peer-reviewed articles on it and physicists disagree with its results (Extended Heim Theory).
D146 is an assessment: possible near-term use replacing satellite ion thrusters, extensive development still needed for air and near-space use, and no practical use beyond the solar system without Breakthrough Propulsion Physics. It lays out phases to 2050 ending in prototype flight tests, and closes by saying the future needs to be focused more on science and engineering and less on science fiction.
See also Inertial Electrostatic Confinement Fusion and Positron Propulsion.
Connections
DIRDs · PURSUE · Inertial Electrostatic Confinement Fusion · Positron Propulsion · Extended Heim Theory · Breakthrough Propulsion Physics · AAP Person Labels