AbstractThis study evaluates the potential performance (efficiency and cost) of inertial fusion reactors assumed capable of vaporizing blankets of various working materials to a temperature (10,000-20,000 K) suitable for economical MHD conversion in a Compact Fusion Advanced Rankine II (CFARII) power cycle. Using a conservative model, 1-D neutronics calculations of the fraction of fusion yield captured as a function of the blanket thickness of Flibe, lithium and lead—lithium blankets are used to determine the optimum blanket thicknesses for each material to minimize CoE for various assumed fusion yields, “generic” driver costs, and target gains. Lithium-hydride blankets are also evaluated using an extended neutronics model. Generally optimistic (“advanced”) combinations of lower driver cost/joule and higher target gain are assumed to allow high enough fusion yields to vaporize and ionize target blankets thick enough to stop most 14 MeV neutrons, and to breed tritium. A novel magnetized, prestressed reactor chamber concept is modeled together with previously developed models for the CFARII Balance-of-Plant (BoP), consisting of a supersonic plasma jet, MHD generator, and “raindrop” condensor. High fusion yields (20 to 80 GJ) are found necessary to heat and ionize the Flibe, lithium, and lead-lithium blankets for MHD conversion, with initial solid thicknesses sufficient to capture most of the fusion yield. Much smaller fusion yields (1 to 20 GJ) are required for lithium-hydride blankets. For Flibe, lithium, and lead—lithium blankets, improvements in target gain and/or driver cost/joule, characterized by a “Bang per Buck” figure-of-merit of ≥ 20 joules yield per driver $, would be required for competitive CoE, while a figure-of-merit of ≥ 1 joule yield per driver $ would suffice for lithium-hydride blankets. Advances in targets/driver costs would benefit any IFE reactor, but the very low CFARII BoP costs (contributing only 3 mills/kWh to CoE) allows this type of reactor, given sufficient advances that non-driver costs dominate, to ultimately produce electricity at a much lower cost than any current nuclear plant.