C J Ham A Bokshi D Brunetti G Bustos Ramirez B Chapman J W Connor D Dickinson A R Field J P Graves T Kiviniemi S Leerink B McMillan S Newton S Pamela C M Roach S Saarelma J Simpson S F Smith P Strand A Virtanen the JET Contributors*
The pedestal plays an important role in determining the confinement in tokamak H-mode plasmas. However, the steep pressure gradients in this transport barrier also lead to edge localized modes (ELMs) [1]. There is good understanding of the pedestal in type I ELM regimes [2], however, type I ELMs are known to damage plasma facing components and f…
Preprint PublishedB. C. G. Reman R. O. Dendy T. Akiyama S. C. Chapman J. W. S. Cook H. Igami S. Inagaki K. Saito M.H. Kim S.G. Thatipamula G. S. Yun
Ion cyclotron emission (ICE) driven by perpendicular neutral beam-injected (NBI) deuterons, together with the distinctive ICE driven by tangential NBI, have been observed from heliotron-stellarator plasmas in the Large Helical Device (LHD). Radio frequency radiation in the lower hybrid range has also been observed, with frequency dependent on plasm…
Preprint PublishedR O Dendy B Chapman B C G Reman J W S Cook
Observations of radiation in the ion cyclotron range of frequencies from the KSTAR tokamak and LHD heliotron-stellarator show that energetic neutral beam injected (NBI) ion populations can relax collectively in the edge plasma near the injection point. The resulting radiation is ion cyclotron emission (ICE), whose spectrum has strongly suprather…
PreprintJacob Chapman Pui-Wai Ma Sergei Dudarev
Fundamental flaws in the Heisenberg Hamiltonian are highlighted in the context of its application to BCC Fe, including the particular issues arising when modelling lattice defects. Exchange integrals are evaluated using the magnetic force theorem. The bilinear exchange coupling constants are calculated for all the interacting pairs of atomic ma…
PublishedB Chapman R O Dendy S C Chapman K G McClements R Ochoukov
Observations have recently been made of ion cyclotron emission (ICE) that originates from the core plasma in the DIII-D and ASDEX-Upgrade tokamaks. In some of these cases, the ICE spectral peaks correspond to the local cyclotron harmonic frequencies of fusion-born ions close to the magnetic axis. This is in contrast to the hitherto usual spatial lo…
PreprintIan Chapman Nick Walkden
Fusion energy is an area of active development and innovation worldwide, with many design concepts exhibiting a range of technical challenges. A significant portion of technical challenges will be unique for a given design concept, however there are several overarching challenges that any design must address to some degree. These include: Tritiu…
Preprint PublishedR O Dendy B Chapman G S Yun S C Chapman K G McClements S G Thatipamula M H Kim A Zalzali
Intense suprathermal radiation, with spectral peaks at multiple harmonics of the deuteron cyclotron frequency, is detected from the outer midplane edge of KSTAR deuterium plasmas that are heated by tangential neutral beam injection (NBI) of 100keV deuterons. We identify how this deuterium ion cyclotron emission (ICE) is generated, and distinguish t…
Preprint PublishedR O Dendy B Chapman S C Chapman K G McClements G S Yun S G Thatipamula M H Kim
During ELM crashes in deuterium plasmas in the KSTAR tokamak, the emitted electromagnetic radiation includes features with sharp spectral structure in the frequency range up to ~900MHz. Cases where the spectral peaks below ~500MHz correspond to proton cyclotron harmonics at the outer midplane edge are explained (B Chapman et al., Nucl.…
Preprint PublishedB Chapman R O Dendy S C Chapman L Holland S W A Irvine and B C G Reman
Observations have recently been made of ion cyclotron emission (ICE) that originates from the core plasma in the DIII-D [1, 2] and ASDEX-Upgrade [3, 4] tokamaks. The ICE spectral peaks correspond to the local cyclotron harmonic frequencies of fusion-born ions close to the magnetic axis, in contrast to the hitherto usual spatial localisation of …
Preprint PublishedB C G Reman R O Dendy T Akiyama S C Chapman J W S Cook H Igami S Inagaki K Saito G S Yun
Ion cyclotron emission (ICE) is detected from all large toroidal magnetically conned fusion (MCF) plasmas. It is a form of spontaneous suprathermal radiation, whose spectral peak frequencies correspond to sequential cyclotron harmonics of energetic ion species, evaluated at the emission location. We first present an account of the worldwide exper…
Preprint Published