A Plan to Develop Dry Wall Chambers for Inertial Fusion Energy with Lasers Page 1 of 46 DRAFT

Goal of the Chambers Plan 1.A path to develop one or more credible dry wall chamber concepts for Laser Fusion Energy. Goal is to achieve this in 2-3 years. 2.By “credible”, we mean one that is realistic and has a reasonable probability for success. i.e.no known major issues (Of course we will not have all the issues nailed down, and the resolution of some issues will have to wait the IRE and ETF.) 3.It is anticipated that one of these concepts will become the basis for the detailed Laser IFE Fusion Power Plant study performed in Phase II.

Outline of Chambers Plan: (Section 1.0) Introduction Description of Laser IFE Principals of HAPL Program Interface Issues (Section 2.0) Identify candidate chamber concepts. (Section 3.0) Identify the issues for each chamber concept Characterize them Front of the first wall- i.e. chamber dynamics & clearing. This is what happens in the chamber At the first wall. This includes materials erosion and fatigue, both short term + long term Behind the first wall (structures) Rank them K= Kiss of death:A fundamental issue that must be resolved or the concept is a non-starter. C = Crucial: A fundamental issue that needs to be addressed before concept is credible. P = Procrastinate: These are issues that need to be solved eventually, but not now. (Section 4.0) Draft a research plan to address the outstanding issues. (Section 5.0) Prioritize the research plans drafted in Section 2.3

Section 1.3: Interface Issues Front of Wall At the Wall Behind the Wall CHAMBERS PLAN threat spectra target design gas/vapor density and temperature target injection final optics laser propagation safety activation, tritium, oxidation, ions, neutrons, heat, shocks materials

Section 2.0: Candidate Chamber Concepts 2.1 Monolithic first wall (Sombrero) > Single material is both armor against “insults” from x-rays and ions, and structure resistant to radiation damage and repeated shocks > Advantage is simplicity 2.2 Armored structures > Separates first wall into a protective layer and underlying structural support. > Exploits that energy deposition & high temperature transients within thin layer 2.3 Engineered first walls > Use advanced fabrication techniques to increase material’s resistance to x-rays, ions, radiation and all that other nasty stuff. 2.4 Advanced ferritic steels > New classes of high temperature ferritic steels: nanocomposited (nano-scale Yttria precipitates) oxide dispersion strengthened ferritics (ODS). > May also use refractory alloy coating of a few microns. 2.5 Magnetic Diversion > Get ions away from wall > Has potential for direct conversion

Section 3.0: Ordering and ranking of issues: The Matrix

Section 4.0: Outline of Research Plan-Part Target Output Continue development of physics in codes Benchmarking target output. 4.2 What hits the wall Fireball propagation 4.3 Target injection 4.4 Chamber dynamics 4.5 First wall mechanical dynamics (structures, topology, strain rates) Computational models X-ray exposure experiments Ion exposure measurements Laser simulations of x-rays and ions Real world materials 4.6 Erosion (mass transport and surface changes) Erosion: thermal, both short and long term Erosion: sputtering, exfoliation, radiation enhanced sublimation

Section 4.0: Outline of Research Plan-Part Radiation damage Pulsed neutron-induced changes in structure mechanical properties Pulsed ion-induced changes in thermo-mechanical properties Pulsed ion/neutron dimensional changes 4.8 Tritium retention 4.9 In-situ repair 4.10 Bonding and cyclic stress of separate armor walls 4.11 Issues specific to engineered first walls 4.12 Issues specific to magnetic deflection