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Author Strait, E. J. ♦ Wu, W. ♦ Yu, J. H.
Source CiteSeerX
Content type Text
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Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Massive Hydrogenic ♦ Mixed-gas Injection ♦ Ex 7-3rb Fast Plasma Shutdown ♦ Reduced Vacuum ♦ Fast Plasma Shutdown ♦ Q-variation Data ♦ Added Impurity ♦ Rich Basis ♦ Massive Gas Injection ♦ Mixed Low-z Gas ♦ 3-ma H-mode Plasma ♦ Normal Tokamak Density ♦ Free-electron Density ♦ More-or-less Uniform Radiative Dissipation ♦ Key Information Relevant ♦ Unconditional Mitigation ♦ 7-mj Plasma Thermal Energy ♦ Mhd Transport Radiation Model ♦ Gas Specie ♦ Delivery Time ♦ Runaway Electron Avalanche Process ♦ Benign Current Decay ♦ Vertical Force Impulse ♦ Collective Specie ♦ Disruption Mitigation Efficacy ♦ Effective Mgi System
Abstract Abstract. Massive gas injection (MGI) experiments with H 2, D 2, He, Ne and Ar and “mixed ” (H 2 + Ar and D 2 + Ne) gases injected into “ITER-similar ” 1.3-MA H-mode plasmas are described. Gas species, injected quantity Q, delivery time, t inj, rate-of-rise and intrinsic and added impurities are found to affect the attributes and “disruption mitigation ” efficacies of the resulting fast plasma shutdowns. With sufficient Q and t inj < ~2 ms, all species provide fast (within � ~3 ms), more-or-less uniform radiative dissipation of the 0.7-MJ plasma thermal energy and fast but benign current decays with reduced vacuum vessel vertical force impulse. With pure and mixed low-Z gases, free-electron densities up to 2x10 21 m-3 are obtained. While these densities are high relative to normal tokamak densities, they are still an order of magnitude smaller than the densities required for unconditional mitigation of the runaway electron avalanche process. Key information relevant to the design of effective MGI systems for larger tokamaks and ITER has been obtained and the collective species and Q-variation data provides a rich basis for validation of emerging 2D + t MHD/transport/radiation models. 1.
Educational Role Student ♦ Teacher
Age Range above 22 year
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Education Level UG and PG ♦ Career/Technical Study
Learning Resource Type Article