Analysis of Mirnov oscillations on PDX

Hammett, G. W.; McGuire, K.

doi:10.2172/5455383

Cited by 8 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A more sophisticated version is fitting the data on the basis of Eq. ( 2), which results in the determination of m and X with error bars [11,12]. To perform such a data analysis, points of equal phase (e.g.…”

Section: Fig 2 Plot Of Sinmentioning

confidence: 99%

MHD mode structure and propagation in the ASDEX tokamak

et al. 1991

View full text Add to dashboard Cite

The Mirnov oscillations observed in the ASDEX tokamak are analysed with regard to the generally accepted interpretation scheme according to which (1) Mirnov oscillations are caused by currents flowing parallel to the magnetic field on rational magnetic surfaces and (2) the field perturbation is frozen within the plasma. If the second statement holds, the frequency is obtained from the profiles of the electron density, the ion temperature and, if applicable, the toroidal or poloidal rotation velocity. It is shown that there are modes which are consistent with the above interpretation. On the other hand, mode coupling is observed. Mode coupling is also invoked to reconcile the experimental findings with the predictions of a theory based on statement (1); according to this theory, there is a poloidal variation of both the phase velocity and the amplitude of the Mirnov oscillations. While the observed phase velocity fits well into this picture, the poloidal variation of the amplitude cannot be ascribed to only one mode in the majority of cases. In addition, the possibility of coherent MHD activity due to currents in the scrape-off layer is discussed.

show abstract

Section: Fig 2 Plot Of Sinmentioning

confidence: 99%

MHD mode structure and propagation in the ASDEX tokamak

et al. 1991

View full text Add to dashboard Cite

show abstract

“…The principal dependence tested by the correlation is T « B^/B^. The factor-oftwo-to-five displacement between theory and experiment is not significant since many simplifying assumptions were made (above) in order to make the comparison, and also the calibration uncertainty of the Mirnov signal [7] alone could account for the difference. Possibly of more significance is the comparison of the peak loss rates with the off-resonance 'Mode Particle Pumping' loss rates (Fig.4 of Ref.…”

Section: Figs 6-8)mentioning

confidence: 99%

“…In previous PDX publications, fishbones were considered to be only those events where an oscillation of 10-20 kHz is observed. Here we examined all events where the MHD signal is coupled to the plasma edge so that an oscillating signal is seen on the Mirnov coils [7]. Often, an energetic ion loss is inferred from the neutron emission for these events.…”

Section: Instantaneous Confinement Times R Fimentioning

confidence: 99%

Studies of energetic ion confinement during fishbone events in PDX

et al. 1985

Self Cite

View full text Add to dashboard Cite

ABSTRACT. The 2.5 MeV neutron emission from the beam-target d(d, n) 3 He fusion reaction has been examined for all PDX deuterium plasmas which were heated by deuterium neutral beams. The magnitude of the emission was found to scale classically and to increase with T* n as expected when electron drag is the primary energy degradation mechanism. The time evolution of the neutron emission through fishbone events was measured and used to determine the confinement properties of the energetic beam ions. Many of the experimental results are predicted by the Mode Particle Pumping Theory.

show abstract

“…At the same time, there was an increase in the loop voltage and the plasma position. In addition, the high frequency Mirnov coils [23] observed an m/n = 4/1 mode in the plasma before the occurrence of the glitch at 65 msec. At the limiter q was roughly 5 at this time.…”

Section: Resultsmentioning

confidence: 99%