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The experimental studies on zonal flows and turbulence have been carried out in Compact Helical System [K. Matsuoka, S. Kubo, M. Hosokawa, in Plasma Physics and Controlled Nuclear Fusion Research, Proc. 12th Int. Conf., Nice, 1988 (International Atomic Energy Agency, Vienna, 1989, Vol. 2, p. 411] using twin heavy ion beam probes. The paper presents the experimental observations of stationary zonal flow, nonlinear couplings between zonal flow and turbulence, and the role of zonal flow in the improved confinement, together with the recent discovery of zonal magnetic field. The presented experimental results strongly support the new paradigm that the plasma transport should be considered as a system of drift wave and zonal flows, and provides the first direct evidence for turbulence dynamo that the structured magnetic field can be really generated by turbulence. © 2008 American Institute of Physics.

The present status of experiments on zonal flows in magnetic confinement experiments is examined. The innovative use of traditional and modern diagnostics has revealed unambiguously the existence of zonal flows, their spatio-temporal characteristics, their relationship to turbulence and their effects on confinement. In particular, a number of observations have been accumulated on the oscillatory branch of zonal flows, named geodesic acoustic modes, suggesting the necessity for theories to give their proper description. In addition to these basic properties of zonal flows, several new methods have elucidated the processes of zonal flow generation from turbulence. Further investigation of the relationship between zonal flows and confinement is strongly encouraged as cross-device activity including low temperature, toroidal and linear devices. © 2007 IAEA.

A zonal magnetic field is found in a toroidal plasma. The magnetic field has a symmetric bandlike structure, which is uniform in the toroidal and poloidal directions and varies radially with a finite wavelength of mesoscale, which is analogous to zonal flows. A time-dependent bicoherence analysis reveals that the magnetic field should be generated by the background plasma turbulence. The discovery is classified as a new kind of phenomenon of structured magnetic field generation, giving insight into phenomena such as dipole field generation in rotational planets.

This is a report on fluctuation measurements using twin heavy ion beam probes in CHS. The observation shows that dozens of coherent modes with intermittent nature co-exist in an electron cyclotron heated plasma. The modes are found to have a long-distance correlation in the toroidal direction. The radial structure of the modes is evaluated in potential fluctuation. The characteristics are consistent with those of the geodesic acoustic modes. © 2006 IOP Publishing Ltd.

This Letter presents experimental confirmation of the presence of zonal flows in magnetically confined toroidal plasma using an advanced diagnostic system--dual heavy ion beam probes. The simultaneous observation of an electric field at two distant toroidal locations (approximately 1.5 m apart) in the high temperature (approximately 1 keV) plasma provides a fluctuation spectrum of electric field (or flow), a spatiotemporal structure of the zonal flows (characteristic radial length of approximately 1.5 cm and lifetime of approximately 1.5 ms), their long-range correlation with toroidal symmetry (n=0), and the difference in the zonal flow amplitude with and without a transport barrier. These constitute essential elements of turbulence-zonal flow systems, and illustrate one of the fundamental processes of structure formation in nature.

Takashi Kamatani,1 Takemichi Okada,2 Hiroyoshi Iguchi,2 Yoshihito Takahashi,3 Hiroaki Yokomori1 1Department of Internal Medicine, 2Department of Radiology, 3Department of Surgery, Kitasato University Medical Center, Saitama, Japan Abstract: A 65-year-old man with long-term alcohol abuse presented with intermittent fever. Abdominal computed tomography revealed multiple masses. Abscess blood and pus cultures conducted after percutaneous catheter drainage with pigtail catheters yielded Salmonella choleraesuis. Antibiotic treatment with meropenem was started using multiple catheters in the liver. Drainage catheters in different locations were exchanged several times with larger-bored catheters. After septicemia was detected, abscesses spread to the peritoneal cavity. Pleural complications developed. Antibiotic treatment, with careful drainage guided by ultrasound or computed tomography, controlled the abscesses and complications. This report describes the difficult clinical course and treatment of a liver abscess from S. choleraesuis. Keywords: liver abscess, Salmonella choleraesuis, bacteremia, CT

Various probing beams have been developed and used for plasma diagnostics in thermonuclear fusion research for magnetic confinement. The required beam current, beam size, energy, beam characteristics such as divergence, energy spread, and emittance, etc., as well as ion species are different depending on the purpose of diagnostics, target plasma size and parameters. Hydrogen beams are used for charge-exchange recombination spectroscopy (CHERS) and motional stark effect (MSE) spectroscopy. Suitable beam energy for CHERS ranges in the area of 50 keV/amu, and a small beam divergence is required for MSE measurements. Heating beams are often used as diagnostic beams by sharing. Neutral lithium probing beams have been used as effective tools for measurement of density and fluctuations. A heavy ion beam probe (HIBP), made from alkali metal ions, is injected directly without neutralization to measure plasma potential and density, as well as their fluctuations. Recent progress in magnetic fusion experiments has resulted in advancement of the development of negative ion sources, such as [He.sup.-] and [Li.sup.-] sources for alpha-particle measurement, because of their advantages with regard to efficient neutralization in the high-energy region, and an [Au.sup.-] source for HIBP with the application of tandem acceleration.

A 6 MeV heavy ion beam probe (HIBP) is being designed for potential measurement on the Large Helical Device (LHD). This article describes a method to control the 3-D probing beam trajectories in the helical magnetic field, an estimate of beam attenuation and energy reduction arising from the long paths in the plasma and a cylindrical analyzer as a candidate for the energy analyzer.

Experimental studies on E X B drift rotational transform for toroidal plasma confinement were carried out using a bumpy torus NBT-1M. An inward radial electric field was observed, which induced E X B poloidal precession and formed closed drift surfaces in a conventional ECH configuration. However, the confinement was degraded by the plasma convective loss due to the asymmetric potential profile and core electrostatic fluctuations. By the use of a combination of two frequencies for ECH (18 GHz and 8.5 GHz), we could reduce both the potential asymmetry and the fluctuation. In this operation, the plasma confinement by E X B drift rotational transform was demonstrated more clearly than that in the conventional single frequency operation.

The feasibility of a heavy ion beam with a tandem acceleration system for plasm potential measurement has been examined. A plasma-sputter-type ion source which produces an [Au.sup.-] beam with an energy width as small as 6 eV and a reasonably small emittance of [Pi] mm-mrad [(MeV).sup.1/2], can be used for thi purpose. Suitable target gas thickness for a charge exchange is estimated to be less than [10.sup.15] atom/[cm.sup.2] at the 3 MV terminal voltage.