The He Brayton cycle appears to be the best near-term power conversion method for maximizing the economic potential of fusion. Key factors affecting the Brayton cycle efficiency includes the turbine inlet temperature, compressor and turbine adiabatic efficiencies, recuperator effectiveness and cycle fractional pressure loss. The compression ratio is also important because for fusion conditions, structural and turbomachinery limitations often prevent use of an optimum value. This paper examines in detail these parameters and proposes near-term values for fusion power plant studies based on existing products and test results, current knowledge, and, if justified, reasonable extrapolation.