The linear and nonlinear kinetic properties of electrostatic oblique waves below the lower hybrid frequency are investigated. For propagation angles # = k k =k ? < q m e =m i the waves are damped by either parallel electron Landau or ion cyclotron damping. For T i =T e 1 the waves are only weakly damped and can propagate. These waves are called slow ion cyclotron (SIC) and slow ion acoustic (SI...

The omega or pseudochiral medium is an artificial complex medium [1], which can be fabricated by doping a host isotropic medium with Ω-shaped planar conducting microstructures. An externally applied field induces both an electric and magnetic polarization, which are perpendicular to each other. The electromagnetic properties of these magnetoelectric media can be used in the design of reciprocal...

Using a novel three-dimensional electromagnetic hybrid code, XHYPERS, we simulate the generation of lower oscillations in magnetized plasma by heavy ion beam with ring-shaped velocity distribution over much longer periods time compared to previous simulations. We introduce phenomenological (effective) electron damping represent induced scattering lower-hybrid waves whistlers and loss energy thr...

In the present paper we consider the interaction between energetic ions and lower hybrid waves in tokamak plasmas and study the parametric dependence of the threshold condition for stochastic ion di usion. It is shown that the threshold condition as obtained in the work by Karney [C. F. F. Karney, Phys. Fluids 22, 2188 (1979)] may be not easily satis ed in present day large tokamaks, but can at...

The next step toward fusion as a practical energy source is the design and construction of ITER. ITER relies in part on ion-cyclotron radio frequency (ICRF) power to heat the deuterium-tritium plasma to fusion temperatures as well as to provide a portion of the current during flat-top operations. Lower hybrid (LH) RF power is under consideration as an upgrade to the baseline heating and current...

Sawteeth have been suppressed by lower hybrid current drive in high density Alcator C plasmas. At a density of 1.1 x 101 4 cm-3 and q(a) = 4.7 the sawteeth were eliminated by application of P,.f = 600 kW at 4.6 GHz, which represents an estimated 30% of the rf power required to fully sustain the discharge in the absence of ohmic power. Strong electron heating is observed with both current drive ...

The goal of the lower hybrid current drive (LHCD) program on Alcator C-Mod is to develop and optimize ITERrelevant steady-state plasmas by controlling the current density profile. Using a 4x16 waveguide array, over 1 MW of LH power at 4.6 GHz has been successfully coupled to the plasmas. However, current drive efficiency precipitously drops as the line averaged density (ne) increases above 1020...

The goal of the Lower Hybrid Current Drive (LHCD) system on the Alcator C-Mod tokamak is to investigate current profile control under plasma conditions relevant to future devices such as ITER and DEMO. Experimental observations of an LHCD " density limit " for C-Mod are presented in this paper. Bremsstrahlung emission from relativistic fast electrons in the core plasma drops suddenly above line...

The critical temperature gradient model of Rebut, Lallia and Watkins is compared with data from Alcator C. The predicted central electron temperature is derived from the model, and a simple analytic formula is given. It is found to be in quite good agreement with the observed temperatures on Alcator C under ohmic heating conditions. However, the thermal diffusivity postulated in the model for g...

Heliospheric (HSP) radio emission detected by the Voyager spacecraft between 1.8 kHz and 3.6 kHz from the distant heliosphere is interpreted as emission generated close to and at the heliopause (HP), the interface between the ionised very local interstellar (LIC) gas and the supersonic solar wind (SW) stream. Radio emission is assumed to be triggered by secondary charge exchange ionisation of i...