Experimental Study On Unstable Electron Beam Instability

Based on the domestic and international research on the device runawayelectrons and plasma disruptions remission for more comprehensive research on thetokamak plasma generated within the phenomenon of runaway electrons, featuresand its inhibition and tokamaks runaway electrons generation mechanism, energylimits and detection means, and so do a more comprehensive description; andTEXTOR-94and HT-7was introduced by the representative of the current majorinternational tokamak and recent experimental study of runaway electrons.HT-7in a series of experiments carried out on from the runaway electrons andinstability wave resonance occurs for the anomalous Doppler, electron cyclotronresonance heating (ECRH) on the runaway electron beam instability and the impactof co-LHCD and IBW under the action of the characteristics of the three aspects ofrunaway electrons starting on the dynamic characteristics of runaway electrons tocarry out some research. Through experimental study found that when the runawayelectrons and instability wave generating anomalous Doppler resonance effect willbe greatly enhanced when the runaway electrons helix angle, helix angle increasesrunaway electrons will enhance the runaway electrons synchrotron radiation powerloss, which can effectively reduce the energy of the electrons escape.However, dueto high energy runaway electrons in parallel, the velocity distribution inhomogeneity,inspired instability waves, while the runaway electrons and instability wave couplinganomalous Doppler resonance will occur, causing a runaway electron beaminstability occurs. Therefore, by electron cyclotron resonance heating (ECRH)reduce energy runaway electrons parallel to change the electron velocity distribution,reducing the electron velocity distribution uniformity, thereby reducing the runaway electron beam instability occurs.Experiments show when the LHW and IBW exist in the plasma, the escapingelectron yield has improved significantly. Experiments show when the LHW andIBW exist in the plasma, the escaping electron yield has improved significantly. TestParticle simulation results confirmed the presence of two waves, the electrondistribution function through LHW and quasi-linear diffusion coefficient of IBWrelies on two waves, so escape yield increase is due to the synergistic interactionbetween two kind of wave. Under the influence of the collaboration, fast electronsgenerated by the tail exceeds the critical energy escape, and the escape yield a greatcontribution.