Measurement of magnetic field fluctuations within last closed flux surface with movable magnetic probe array in the JIPP T-IIU tokamak

Kitachi, K.; Oike, T.; Ohdachi, S.; Toi, K.; Akiyama, R.; Ejiri, A.; Hamada, Y.; Kuramoto, H.; Narihara, K.; Seki, T.

doi:10.1016/s0920-3796(96)00552-2

Cited by 3 publications

(4 citation statements)

References 7 publications

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“…It is found that when the magnetic probe was gradually moved inward the magnetic fluctuation levels continually increased and did not show saturation tendency. Similar results have been found in other devices [2,3]. The electron thermal conductivity caused by magnetic fluctuations was calculated by a quasi-linear estimate which is developed by Rechester and Rosenbluth [5].…”

Section: Resultssupporting

confidence: 81%

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Electron thermal transport induced by magnetic turbulence in the HT-7 tokamak

Zhang

Wan

2007

Journal of Nuclear Materials

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Section: Resultssupporting

confidence: 81%

“…The magnetic fluctuations driven anomalous transport has been investigated in many fusion devices [2][3][4]8,9]. Some theories have also been developed to calculate the electron thermal conductivity [5,6].…”

Section: Introductionmentioning

confidence: 99%

Electron thermal transport induced by magnetic turbulence in the HT-7 tokamak

Zhang

Wan

2007

Journal of Nuclear Materials

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“…Toroidal displacement (Rφ) can also be reduced to the integration of Ãφ and to the double integration ˜ on the beam trajectory and R exit φ| exit − R in φ| in = 0. The broadband magnetic field in the vacuum (outside the plasma column) as well as inside the plasma column, was measured by inserting a small magnetic probe into the tokamak plasmas [52,53]. We found that the magnetic fluctuations decrease very rapidly as Bθ ∝ r −m .…”

Section: The Principles Of Local Magnetic Field Measurement Using Hibpmentioning

confidence: 95%

Microtearing mode (MTM) turbulence in JIPPT-IIU tokamak plasmas

et al. 2015

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Magnetic, density and potential fluctuations up to 500 kHz at several spatial points have been observed in the core region of JIPPT-IIU tokamak plasmas using a heavy ion beam probe. The frequency spectra of the density and magnetic oscillations are found to be similar, whereas there are large differences in the phase, coherence and frequency dependences deduced from signals at adjacent sample volumes. These differences allow us to ascribe the detected magnetic fluctuations to the microtearing mode (MTM) by simple dispersion relations of the MTM in collisionless and intermediate regimes. The frequency-integrated level of magnetic fluctuations around 150 kHz (100-200 kHz) is Br /B t ≈ 1 × 10 −4 , a level high enough for the ergodization of the magnetic surface and enhanced electron heat loss as derived by Rechester and Rosenbluth (1978 Phys. Rev. Lett. 40 38). This level is consistent with the measurements performed using cross-polarization scattering of microwaves in the Tore Supra tokamak. Our results are the first direct experimental verification of the MTM in the core region of tokamak plasmas, which has been recently observed in gyrokinetic simulations using a very fine mesh in tokamak and ST plasmas.

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“…This probe array is put inside a thin stainless pipe protected with c/c-composite carbon sleeve with 20% boron. 6,7 The carbon sleeve also acts to minimize deleterious effects on a plasma, evaporating boron during a plasma shot. In NBI heated plasmas of CHS, this probe array was inserted into a plasma up to ͗r͘/͗a͘ Ӎ0.9, in order to investigate effects of the inserted probe on the plasma behavior.…”

Section: Details Of Movable Magnetic Probe Arraymentioning

confidence: 99%

Movable magnetic probe array for toroidal Alfven eigenmodes study in the compact helical system heliotron/torsatron

Takechi

Toi

1999

Review of Scientific Instruments

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Articles you may be interested inAlfvén eigenmodes excitation by external loop antennas in the Compact Helical System heliotron/torsatron Rev. Sci. Instrum. 72, 405 (2001); 10.1063/1.1319608 A system for Alfvén-eigenmode spectroscopy using electrodes inserted into the compact helical system heliotron/torsatron plasma Rev. Sci. Instrum. 72, 402 (2001); 10.1063/1.1316749 Study of structural effects of Langmuir probe array on edge fluctuation measurement in the compact helical system heliotron/torsatron Rev. Sci. Instrum. 72, 446 (2001); 10.1063/1.1315640 Escaping fast ion diagnostics in compact helical system heliotron/torsatron Rev. Sci. Instrum. 70, 827 (1999); 10.1063/1.1149404Langmuir probe array for edge plasma study on the compact helical system heliotron/torsatron Rev.A movable magnetic probe array is installed on the compact helical system ͑CHS͒ heliotron/ torsatron to study Alfven eigenmodes exited by energetic beam ions. The array consists of six sets of magnetic probes for measurements of radial and poloidal magnetic field fluctuations. This probe array is put inside a thin stainless pipe protected with a c/c-composite carbon sleeve containing 20% boron. The carbon sleeve also acts to minimize deleterious effects on a plasma, evaporating boron during a plasma shot. By using this probe array, radial profiles of magnetic fluctuations in the range of f Ͻ200 kHz can be obtained even inside the last closed flux surface up to ͗r͘/͗a͘ϳ0.8 without serious disturbances to the neutral beam injection ͑NBI͒ heated CHS plasmas. High frequency magnetic fluctuations less than 200 kHz related to the toroidal Alfven eigenmodes ͑TAE͒ are detected with these magnetic probe arrays in NBI heated plasmas. The mode numbers of the observed TAE can be successfully determined by combination of the radial profiles of fluctuations obtained with the movable probe array and a set of poloidal and toroidal arrays of Mirnov probes.

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Measurement of magnetic field fluctuations within last closed flux surface with movable magnetic probe array in the JIPP T-IIU tokamak

Cited by 3 publications

References 7 publications

Electron thermal transport induced by magnetic turbulence in the HT-7 tokamak

Electron thermal transport induced by magnetic turbulence in the HT-7 tokamak

Microtearing mode (MTM) turbulence in JIPPT-IIU tokamak plasmas

Movable magnetic probe array for toroidal Alfven eigenmodes study in the compact helical system heliotron/torsatron

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