SPHEROMAK REACTOR - PHYSICS OPPORTUNITIES AND ISSUES

The spheromak is a magnetic confinement device with a more attractive fusion reactor potential than the leading geometry, the tokamak. This results in large part from the absence of a toroidal field coil and ot her structures linking the plasma along the geometric axis. However, b ecause of the lack of a strong external magnetic field, the physics is more complex so that considerable research is required to learn how t o achieve the reactor potential. Several critical physics issues are c onsidered here, including stability to low mode number magnetohydrodyn amic (MHD) modes, energy confinement, helicity injection and current d rive, the magnetic turbulence associated with this dynamo, and the bet a (ratio of plasma and magnetic pressures) which can be supported in t he geometry.