Industry cooperates to advance IFE reactor design-the results of Prometheus

An industry team, led by McDonnell Douglas Aerospace, has developed two inertial fusion energy reactor plant designs that are predicted to compete favorably with other energy sources. Symmetrically illuminated, direct drive targets were chosen for the KrF laser driver for better gain at a lower cost. The 4 MJ pulse energy to the target is provided by 960 medium-sized (6 kJ) electric discharge lasers. This provides redundancy, system reliability, and stringent illumination requirements. Innovative non-linear optics (NLO) design for beam combination and pulse compression converts the beams into temporally-shaped, high quality beams. The 60 beamlines are shielded to minimize the radiation to the reactor and driver buildings. Long-lived, aluminum-coated, grazing incidence metal mirrors (GIMM), supported by SiC structure, are located within 20 meters of the center of the reactor cavity. These GIMMs and the final focusing mirrors are high-speed, adaptable structures that help steer the beams to the position of the tracked target. The second reactor design uses an innovative, lower-cost, pulsed, single beamline LINAC to deliver heavy ion beams into 14 storage rings. Tailoring of the beam storage, compression, and extraction from the storage rings provides the required temporal and energy shaping. The sets of beams are divided to illuminate the indirectly-driven target from two sides with 7 MJ of energy. The beams are focused to a point on the backside of the blanket where the beams are stripped to a high charge state. This enables formation of a small diameter transport channel through the blanket and across the cavity to the target. The first wall system for both designs uses a SiC structure cooled internally and on the surface with liquid lead. The lead is evaporated and recondensed on the surface to protect and cool the first wall from the 3 to 5 Hz target explosions. The blanket is a Li₂ O solid breeder, cooled with low pressure helium. The two Prometheus IFE reactor designs show that IFE has the potential to be economically competitive with very attractive safety and environmental features while maintaining a high degree of technical credibility