Recent results from the SSPX spheromak experiment demonstrate the potential for obtaining good energy confinement (Te> 350eV and radial electron thermal diffusivity comparable to tokamak L-mode values) in a completely self-organized toroidal plasma. A strong decrease in thermal conductivity with temperature is observed and at the highest temperatures, transport is well below that expected from the Rechester-Rosenbluth model. Addition of a new capacitor bank has produced 60% higher magnetic fields and almost tripled the pulse length to 11ms. For plasmas with T{sub e}> 300eV, it becomes feasible to use modest (1.8MW) neutral beam injection (NBI) heating to significantly change the power balance in the core plasma, making it an effective tool for improving transport analysis. We are now developing detailed designs for adding NBI to SSPX and have developed a new module for the CORSICA transport code to compute the correct fast-ion orbits in SSPX so that we can simulate the effect of adding NBI; initial results predict that such heating can raise the electron temperature and total plasma pressure in the core by a factor of two.

Experimental results from the Sustained Spheromak Physics Experiment, SSPX, are reviewed and applied to published reactor configurations. The results include several important features, including low fluctuation levels, (apparent) good magnetic flux surfaces, and moderate beta. Additional features needed for an attractive reactor but not yet demonstrated experimentally are identified by comparison with the reactor designs, and possible alternatives to a fully steady-state device are discussed.