• Targets for all laser-driven IFE concepts (both direct-drive and indirect-drive) can be tested on the NIF. In particular, reliable target performance would need to be demonstrated before investments could confidently be made in the development of laser-driven IFE target designs.
The NIF will also be helpful in evaluating indirectly driven, heavy-ion targets. It will be less helpful in gathering information relevant to current Z-pinch, heavy-ion direct-drive, and heavy-ion advanced target concepts.
OVERARCHING CONCLUSION 2: It would be advantageous to continue research on a range of IFE concepts, for two reasons:
• The challenges involved in the current laser indirect-drive approach in the single-pulse NNSA program at the NIF have not yet been resolved, and
• The alternatives to laser indirect drive have technical promise to produce high gain.
In particular, the panel concludes that laser direct drive is a viable concept to be pursued on the NIF. SNL’s work on Z-pinch can serve to mitigate risk should the NIF not operate as expected. This work is at a very early stage but is highly complementary to the NIF approach, because none of the work being done at SNL relies on successful ignition at the NIF and key aspects of the target physics can be investigated on the existing Z-machine. Finally, emerging heavy-ion designs could be fruitful in the long term.
OVERARCHING RECOMMENDATION: The panel recommends against pursuing a down-select decision for IFE at this time, either for a specific concept such as LIFE or for a specific target type/driver combination.
Further research and development will be needed on indirect drive and other ICF concepts, even following successful ignition at the NIF, to determine the best path for IFE in the coming decades.