Magnetohydrodynamic Instability with Neutral-Beam Heating in the ISX-BTokamak

This paper describes observations of magnetohydrodynamic instability with neutralbeam heating in the ISX-$B$ tokamak and the theory specifically developed to support these experiments. The observed magnetohydrodynamic activity is explained by the resistive model presented but is not responsible for the observed degradation of confinement. Increasingly important $n>\mathrm{}1\mathrm{}$ pressure-driven modes are predicted by the theory for the higher experimental ${\beta }_p$ values, but there is no experimental verification of their presence.