A. K. Ram J. Decker A. Bers R. A. Cairns C. N. Lashmoredavies
The high-ß magnetically confined plasmas in spherical tori (ST), like NSTX and MAST, provide a unique opportunity for a wide variety of applications of electron Bernstein waves (EBW). These applications range from heating of the ST plasma to modifying and controlling its current profile. Using the fully relativistic dielectric tensor for a Maxwell…
PublishedC. N. Lashmoredavies V. Fuchs A. K. Ram
The fast wave approximation, extended to include the effects of electron dissipation, is used to calculate the power mode converted to the ion hybrid (Bernstein) wave in the vicinity of the ion hybrid resonance. The power absorbed from the fast wave by ion cyclotron damping and by electron Landau and transit time damping (including cross terms) is …
PublishedC. N Lashmoredavies D. A. Russell
The propagation of the ion hybrid wave in a deuteriumtritium plasma and in the presence of a small population of fusion alphaparticles is analysed. A non-thermal distribution of alpha-particles is considered which is relevant to their distribution before they have slowed down. Non-thermal distributions are also relevant to large excursion orbit alp…
PublishedR. A. Cairns C. N. Lashmoredavies D. C. Mcdonald M. Taylor
In a fusion plasma ion cyclotron heating may be applied to a plasma in a regime where there is a population of ions whose Larmor radius is not small compared to the perpendicular wavelength. In this case the equations describing the propagation and absorption of the wave are integro-differential, describing the non-local response of the plasma to t…
PublishedK. G. McClements R. O. Dendy C. N. Lashmoredavies G. A. Cottrell S. Cauffman et al.
Ion cyclotron emission ~ ICE ! has been observed during neutral beam-heated supershots in the Tokamak Fusion Test Reactor ~ TFTR ! @ Phys. Rev. Lett. 72 , 3526 ~ 1994 !# deuterium–tritium campaign at fusion product cyclotron harmonics. The emission originates from the outer midplane edge plasma, where fusion products initially have an anisotropic…
PublishedB. M. Harvey C. N. Lashmoredavies
It can be shown that whistler waves with low parallel phase velocity can be subject to strong cyclotron damping, even when the wave frequency is well below the cyclotron frequency. This resonance arises as a result of the Doppler effect which is proportional to the plasma density and increases the frequency experienced by electrons moving in the op…
PublishedPeter J. Catto C. N. Lashmoredavies T. J. Martin
Nearly all kinetic treatments of fast wave minority heating of inhomogeneous plasma in the cyclotron range of frequencies assume the magnetic field varies in the direction perpendicular to the magnetic field. However, the toroidal magnetic field of a tokamak varies along a field line due to the rotational transform and causes a small number of trap…
PublishedR. O. Dendy C. N. Lashmoredavies K. F. Kam
The magnetoacoustic cyclotron instability is a mechanism by which waves on the perpendicular fast Alfvén-ion Bernstein branch can be excited through cyclotron resonance with an energetic ion population. It is a candidate emission mechanism for the superthermal ion cyclotron radiation, apparently associated with the products of fusion reactions, th…
PublishedC. N. LashmoreDavies V. Fuchs R. O. Dendy
A full-wave equation has been obtained from the gyrokinetic theory for the fast wave traversing a minority cyclotron resonance [Phys. Fluids B 4, 493 ( 1992)] with the aid of the fast wave approximation [Phys. Fluids 31, 1614 (1988)]. This theory describes the transmission, reflection, and absorption of the fast wave for arbitrary values of the par…
PublishedR. O. Dendy C. N. Lashmoredavies K. F. Kam
Intense superthermal ion cyclotron emission (ICE) has been observed from tokamak plasmas. The power spectrum displays narrow peaks at multiple harmonics of the background ion cyclotron frequency [Cottrell and Dendy, Phys. Rev. Lett. 60, 33 (1988)] in Ohmic deuterium plasmas, and the radiation appears to be driven by the fusion ion population in the…
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