EFDA-JET-CP(00)303

Energetic Particle Physics and MHD Stability in JET and START

Data from sawtoothing JET discharges with Ion Cyclotron Resonance Heating (ICRH) has revealed a correlation between the heated ion contribution to the m = 1 kink energy and the Shafranov shift gradient at q = 1, consistent with theory. A correlation has also been found between the total energetic particle kink energy and sawtooth period in a sequence of JET pulses with different beam tritium concentrations. Neutral Particle Analyser (NPA) measurements of alpha particles in JET, which reveal MeV deuterons resulting from nuclear elastic scattering, can in principle yield information on alpha particle anisotropy. The spherical tokamak geometry in START has provided a rigorous test of Toroidal Alfvén Eigenmode (TAE) theory: independent codes give consistent results for TAE mode frequencies and structure. A mechanism capable of explaining the excitation of chirping fishbones by circulating beam ions in START has also been identified.
Name Size  
EFDC00303 409.17 Kb