Propagation and damping of the fast Alfven wave in the Texas Tech Tokamak



Journal Title

Journal ISSN

Volume Title


Texas Tech University


Propagation and damping of the fast Alfven wave has been investigated for a deuterium-hydrogen plasma in a small research Tokamak. Magnetic probes served as the principle diagnostic in studying the waves* dispersion characteristics, the eigenmode Q's and the radial profiles of the electrical field polarization. Results indicate that a simple cylindrical model is sufficient for predicting the waves* dispersion properties, Q measurements supply strong evidence that the fast wave damping is dependent on resonance layers in the plasma. The dependence of Q on percentage hydrogen in the predominantly deuterium plasma suggests that mode conversion of the fast wave to the ion Bernstein wave at the ion-ion hybrid resonance layer may be occurring. The measured field patterns differed substantially from theoretical expectations and no localized resonance layer effect was detected in the polarization profiles. However, a more quiescent plasma and better spatial resolution of the probe measurements may help in resolving some mode conversion effects.