A thermonuclear ballooning eigenmode of an electrostatic perturbation in a toroidal plasma is obtained with inclusion of the toroidal couplings as well as the magnetic shear effects. In the presence of high-energy, slowed-down alpha particles, the mode is driven by the combined effect of the total pressure gradient of ion species (alphas and host ions) and the toroidal curvature. We include the kinetic effects, i.e. the finite gyroradius and wave-particle interactions. The ballooning mode is always unstable and no critical density of alphas is found for the onset of the instability. Associated anomalous particle fluxes are estimated. We find that the ratio of alpha flux and ion one is roughly proportional to the ratio of their pressure gradients.
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