Low frequency resonance cone structure in a warm anisotropic plasma

Asymptotic analysis of the electrostatic Green’s function for an antenna in a warm, anisotropic, nearly collisionless plasma reveals the presence of new resonance cone structures which exist in addition to the cold plasma resonance cone for frequencies below the lower hybrid frequency. These new cones, the ion acoustic resonance cones, occur for frequencies 0 ⩽ ω ⩽ min(ωpi, ωci) and max(ωpi, ωci) ⩽ ω ⩽ ωlh; they exist only when the electron temperature is nonzero and are important when Ti/Te ≪ 1. The interference structure associated with this cone is quite sensitive to the ion temperature and could be the basis of an ion temperature diagnostic technique for plasmas that meet the conditions of the theoretical derivation: Ti/Te ≪ 1 and ωci ≫ ωpi.