IFE power plant principles. Target fabrication and positioning

For inertial fusion energy (IFE) to become attractive the manufacturing process of targets must become more rapid, reliable and inexpensive. Fabrication of targets involves challenges not normally present in commercial manufacturing, i.e., handling of radioactive materials, processing at cryogenic temperatures and maintaining extraordinary dimensional precision of miniature components. Of all IFE technology building blocks the mass production of targets has the least foundation in experiment and demonstrated technology. However, the IFE community has identified the major issues and requirements that are involved. This document discusses the requirements imposed by the physics of target implosions on target manufacturing and positioning, as well as constraints from the chamber environment, safety and environmental concerns and overall plant performance and economics. It discusses (i) basic capsule fabrication and filling; (ii) tritium inventory; (iii) hohlraums, sabots and target assembly; (iv) target injection, tracking and beam pointing; and (v) target heating during injection. A set of key issues and needs are identified: (1) simplification of capsule and hohlraum configurations to their essence; (2) controlled mass micro encapsulation resulting in narrow distributions of shell size and wall thickness must be perfected; (3) new coating processes for higher coating rates are needed; (4) the shell surface quality must be improved; (5) the search for shell and coating materials needs to be widened; (6) new DT filling processes must be developed to minimize filling time and tritium inventory; (7) tritium inventory itself is a major limitation; (8) rapid quality control diagnostics for production line application must be developed; (9) rapid casting techniques with adequate dimensional precision and surface quality must be developed; (10) cryogenic guns for 10 Hz operation for 100 million shots must be developed, while the tracking of injected targets must be demonstrated; and (11) the state of the cryogenic fuel might be more sensitive to heat transfer during injection than previously thought, requiring better calculations. 41 refs, 7 figs, 7 tabs