R. Scannell H. Liu E. Mukhin E. Yatsuka A. Gorbunov L. Giudicotti G. Kurskiev J. Chen M. A. Van Zeeland D. Finkenthal R. Imazawa D. Brower A. Sirinelli T. Akiyama T. Carlstrom D. Johnson M. Lesher C. Watts M. Bassan
This paper provides an overview of the status of the laser diagnostics to be implemented on ITER. This includes descriptions of the Thomson scattering in the Core, Edge and Divertor regions, polarimetry and interferometry diagnostics used for measuring plasma density and also measurements of Helium density in the divertor using Laser Induced Flo…
PreprintB. C. G. Reman R. O. Dendy T. Akiyama M. Salewski S. C. Chapman J. W. S. Cook H. Igami S. Inagaki K. Saito R. Seki G. S. Yun
During bursty MHD events, transient ion cyclotron emission (ICE) is observed from deuterium plasmas in the Large Helical Device (LHD) heliotron-stellarator. Unusually, the frequencies of the successive ICE spectral peaks are not close to integer multiples of the local cyclotron frequency of an energetic ion population in the likely emitting regi…
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 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 PublishedT. Akiyama K. Kawahata K. Tanaka T. Tokuzawa Y. Ito S. Okajima K. Nakayama C. A. Michael L. N. Vyacheslavov A. Sanin S. Tsuji-Iio LHD Experiment Group
This paper describes the interferometer systems on the Large Helical Device (LHD). LHD is equipped with five interferometer systems, each of which has a different operational purpose and measurable electron density range. A single-channel millimeter-wave interferometer is mainly used for low-density plasmas along a horizontal line of sight on the e…
PublishedK. Tanaka K. Kawahata T. Tokuzawa T. Akiyama M. Yokoyama M. Shoji C. A. Michael L. N. Vyacheslavov S. Murakami A. Wakasa A. Mishchenko K. Muraoka S. Okajima H. Takenaga Lhd Experiment Group
Particle confinement processes are studied in detail on the Large Helical Device (LHD). Diffusion coefficients (D) and convection velocities (V) are estimated from density modulation experiments. The magnetic configuration and collisionality are widely scanned in order to investigate parameter dependences of D and V. To study the effect of the magn…
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