Y. Takeiri

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The driving and damping mechanism of plasma flow is an important issue because flow shear has a significant impact on turbulence in a plasma, which determines the transport in the magnetized plasma. Here we report clear evidence of the flow damping due to stochastization of the magnetic field. Abrupt damping of the toroidal flow associated with a transition(More)
  • S Kobayashi, T Mizuuchi, K Nagasaki, H Okada, K Kondo, S Yamamoto +14 others
  • 2008
The energy confinement in the NBI plasmas has been investigated in the helical-axis heliotron device, Heliotron J. The configuration control experiments for bumpiness (ε b), being one of the side-bands of the helical component, show that the plasma performance in NBI plasmas depends on not only the effective helical ripple (ε eff) but also the bumpiness.(More)
The electron density was measured at various bias voltages to understand how the plasma grid bias affects the electron near the plasma grid in large-scaled negative ion sources. It was found that the response of the electron to the bias voltage changes depending on negative ion production processes. The electron density remarkably decreases with increasing(More)
  • S Kubo, T Shimozuma, Y Yoshimura, T Notake, H Idei, S Inagaki +63 others
  • 2004
One of the main objectives of the LHD is to extend the plasma confinement database for helical systems and to demonstrate such extended plasma confinement properties to be sustained in steady state. Among the various plasma parameter regimes, the study of confinement properties in the collisionless regime is of particular importance. Electron cyclotron(More)
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