Ion-Bernstein-Wave Heating in the JIPPT-II-U Tokamak Plasma

Ono, M.; Watari, T.; Ando, R.; Fujita, J.; Hirokura, Y.; Ida, K.; Kako, E.; Kawahata, K.; Kawasumi, Y.; Matsuoka, K.; Nishizawa, A.; Noda, N.; Ogawa, I.; Ohkubo, Κ.; Okamoto, Masayuki; Sato, Kohnosuke; Tanahashi, S.; Taniguchi, Y.; Tetsuka, T.; Toi, K.; Yamazaki, K.

doi:10.1103/physrevlett.54.2339

Cited by 69 publications

(21 citation statements)

References 7 publications

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“…For example, Ono et al found that both stochasticity and collisions were active in tokamak ion heating by radially injected, high-frequency Bernstein waves. 11 Nonlocal ͑inhomogeneous͒ effects such as ion orbit losses and other edge physics have recognized importance in fusion plasmas. 12 In spite of the fundamental importance of these transport processesHamiltonian stochasticity, collisions, and nonlocal effectsthere have been no detailed experimental investigations of particle kinetics in plasmas where several are simultaneously active.…”

Section: Introductionmentioning

confidence: 99%

Observations of fast anisotropic ion heating, ion cooling, and ion recycling in large-amplitude drift waves

1998

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Large-amplitude drift wave fluctuations are observed to cause severe ion temperature oscillations in plasmas of the Caltech Encore tokamak ͓J. M. McChesney, P. M. Bellan, and R. A. Stern, Phys. Fluids B 3, 3370 ͑1991͔͒. Experimental investigations of the complete ion dynamical behavior in these waves are presented. The wave electric field excites stochastic ion orbits in the plane normal (Ќ) to B, resulting in rapid Ќ heating. Ion-ion collisions impart energy along ( ʈ ) B, relaxing the Ќ-ʈ temperature anisotropy. Hot ions with large orbit radii escape confinement, reaching the chamber wall and cooling the distribution. Cold ions from the plasma edge convect back into the plasma ͑i.e., recycle͒, causing further cooling and significantly replenishing the density depleted by orbit losses. The ion-ion collision period ii ϳT 3/2 /n fluctuates strongly with the drift wave phase, due to intense (Ϸ50%͒ fluctuations in n and T. Evidence for particle recycling is given by observations of bimodal ion velocity distributions near the plasma edge, indicating the presence of cold ions ͑0.4 eV͒ superposed atop the hot ͑4-8 eV͒ plasma background. These appear periodically, synchronous with the drift wave phase at which ion fluid flow from the wall toward the plasma center peaks. Evidence is presented that such a periodic heat/loss/recycle/cool process is expected in plasmas with strong stochastic heating.

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Section: Introductionmentioning

confidence: 99%

Observations of fast anisotropic ion heating, ion cooling, and ion recycling in large-amplitude drift waves

1998

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“…In particular, the divergence of the curve for m =3 when g,~0 is prominent, seeming to refiect (51c). On the other hand, for g, ) 1 we anticipate that W reaches its maximum at~= r b /2 when g, = g, . For m = 1, the figure indicates that w(p /~» is 0.5 for g, = 1.5, while g, , = 1.84.…”

Section: Absorbed Energy In Each Harmonicmentioning

confidence: 90%

“…We refer to the experiment in Ref. [1] where He is heated at the third harmonic m =3. The passing time t through the resonant surface or layer may be determined, following Stix's paper [3], by t~(d/dt)[mQ(t)]~=~and~(d/dt)Q(t)=~Q o V~~/ R A~, where A is the aspect ratio in the tokamak.…”

Section: Discussionmentioning

confidence: 99%

“…Then we have r=D(mQORA/mV~~)' and equating this to r3, =(2/&3)g, and using parameters in Ref. [1], i.e. , R =91 cm, A =5, QO=0.…”

Section: Discussionmentioning

confidence: 99%

“…Another main assumption is that an electrostatic wave is propagating across the magnetic field. This is appropriate, e. g., for the ion Berstein wave heating [1,2].…”

Section: Introductionmentioning

confidence: 99%

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Theory of high-power cyclotron-resonance heating in an inhomogeneous magnetic field

Sugihara

Ogawa

1992

Phys. Rev. A

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Wave-energy absorption of a plasma due to cyclotron harmonic resonance is evaluated analytically and by a simulation. The static magnetic field is characterized with B VB =0, and a longitudinal wave is supposed to propagate across the magnetic field. In the calculation an orbit modification of the cyclotron motion of particles is taken into account. It is found that the absorption for the fundamental harmonic resonance (m =1) is depressed from that of the conventional linear theory while the absorptions for m~2 are enhanced, where m is the harmonic number. The enhancement is significant when kp, &(1 (k the perpendicular wave number and p, the gyroradius of the thermal particle) and when the interaction time between the plasma particles and the wave exceeds a critical value that is obtainable analytically. For all m and kp" there appear peaks or saturations in the time evolution of the absorbed energy.PACS number(s): 52.50. Gj, 52.65.+z, 52.35.Fp, 52.35.Nx

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Hot Plasma

Springer Series on Atomic, Optical, and Plasma Physics

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Ion-Bernstein-Wave Heating in the JIPPT-II-U Tokamak Plasma

Cited by 69 publications

References 7 publications

Observations of fast anisotropic ion heating, ion cooling, and ion recycling in large-amplitude drift waves

Observations of fast anisotropic ion heating, ion cooling, and ion recycling in large-amplitude drift waves

Theory of high-power cyclotron-resonance heating in an inhomogeneous magnetic field

Hot Plasma

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