ICRF produced thermal barriers in a three-cell axisymmetric tandem mirror

A thermal barrier plasma potential structure in a three-cell axisymmetric tandem mirror has been produced using only the ion cyclotron range of frequencies (ICRF), with a central cell density of up to 10¹³ cm^-3 and a central cell ion temperature of approximately 40 eV. Thermal barrier like potential dips occurred in the region of a magnetic field gradient, at a magnetic beach of a slow wave launched in the end cell. The barrier formation is a result of a combination of radiofrequency trapping, radiofrequency enhanced potentials and μ∇B forces. The barrier pumping is consistent with μ∇B forces and E_θ × drifts.