403 research outputs found
Reduction of ion thermal diffusivity inside a magnetic island in JT-60U Tokamak plasma
A peaked ion temperature profile is observed inside the magnetic island during mode locking after the back transition from H mode to L mode in JT-60U. The thermal diffusivity evaluated inside the magnetic island is 0.1m2/s, which is much smaller than that outside the magnetic island by an order of magnitude. The present experiment gives clear evidence that ion heat transport inside a magnetic island can bifurcate and the transport level can be suppressed to the very low level associated with the strong flow shear at the boundary
Comparative Study of MHD Instabilities in LHD and JT-60U - Instability at t ~ 0.5 during Counter-NB -
Reduction of Ion Thermal Diffusivity Inside a Magnetic Island in JT-60U Tokamak Plasma
Verification of Analyses of Helical and Tokamak Plasmas Using Broad Band Network toward Building of the Nuclear Fusion Research Grid
Verification of Analysis of Helical and Tokamak Plasma Characteristics with a Broadband Network for Construction of the Fusion Research Grid
Paramagnetic Faraday rotation with spin-polarized ytterbium atoms
We report observation of the paramagnetic Faraday rotation of spin-polarized
ytterbium (Yb) atoms. As the atomic samples, we used an atomic beam, released
atoms from a magneto-optical trap (MOT), and trapped atoms in a
far-off-resonant trap (FORT). Since Yb is diamagnetic and includes a spin-1/2
isotope, it is an ideal sample for the spin physics, such as quantum
non-demolition measurement of spin (spin QND), for example. From the results of
the rotation angle, we confirmed that the atoms were almost perfectly
polarized.Comment: 8 pages, 20 figure
Observation of Localized Oscillations at m/n = 2/1 Rational Surface during Counter Neutral Beam Injection
Transition between Internal Transport Barriers with Different Temperature-Profile Curvatures in JT-60U Tokamak Plasmas
A spontaneous transition phenomena between two states of a plasma with an internal transport barrier (ITB) is observed in the steady-state phase of the magnetic shear in the negative magnetic shear plasma in the JT-60U tokamak. These two ITB states are characterized by different profiles of the second radial derivative of the ion temperature inside the ITB region (one has a weak concave shape and the other has a strong convex shape) and by different degrees of sharpness of the interfaces between the L mode and the ITB region, which is determined by the turbulence penetration into the ITB region
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