Publication

High field side measurements of non-thermal electron cyclotron emission on TCV plasmas with ECH and ECCD

Stefano Coda, Stefano Alberti, Patrick Blanchard, Henri Weisen, Igor Klimanov, Petri Nikkola
2002
Journal paper

Abstract

Measurements of electron cyclotron emission (ECE) from the high field side of the TCV tokamak have been made on plasmas heated by second and third harmonic X-mode electron cyclotron heating (ECH) and electron cyclotron current drive (ECCD). Suprathermal ECE, up to a factor of six in excess of thermal emission, is detected in the presence of second harmonic X-mode (X2) ECCD and of third harmonic X-mode (X3) ECH. The measured ECE spectra are modelled using a bi-Maxwellian describing the bulk and the suprathermal electron populations. Suprathermal temperatures between 10 and 50 keV and densities in the range 1 x 10(17)-6 x 10(18) m(-3) are obtained, and correspond to 3-15 bulk temperatures and 1-20% bulk densities. Good agreement between ECE suprathermal temperatures and energetic photon temperatures, measured by a hard x-ray camera, is found. For optically thin X3 low field side injection in the presence of X2 CO-ECCD, the suprathermal population partly explains the discrepancy between global and first pass absorption measurements.

Official source

https://infoscience.epfl.ch/record/119949?ln=en

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Ontological neighbourhood

Physics

Plasma physics: Fusion power

Related concepts (28)

Tokamak

A tokamak (ˈtoʊkəmæk; токамáк) is a device which uses a powerful magnetic field to confine plasma in the shape of a torus. The tokamak is one of several types of magnetic confinement devices being developed to produce controlled thermonuclear fusion power. , it was the leading candidate for a practical fusion reactor. Tokamaks were initially conceptualized in the 1950s by Soviet physicists Igor Tamm and Andrei Sakharov, inspired by a letter by Oleg Lavrentiev. The first working tokamak was attributed to the work of Natan Yavlinsky on the T-1 in 1958.

Electron cyclotron resonance

Electron cyclotron resonance (ECR) is a phenomenon observed in plasma physics, condensed matter physics, and accelerator physics. It happens when the frequency of incident radiation coincides with the natural frequency of rotation of electrons in magnetic fields. A free electron in a static and uniform magnetic field will move in a circle due to the Lorentz force. The circular motion may be superimposed with a uniform axial motion, resulting in a helix, or with a uniform motion perpendicular to the field (e.

Magnetic confinement fusion

Magnetic confinement fusion is an approach to generate thermonuclear fusion power that uses magnetic fields to confine fusion fuel in the form of a plasma. Magnetic confinement is one of two major branches of fusion energy research, along with inertial confinement fusion. The magnetic approach began in the 1940s and absorbed the majority of subsequent development. Fusion reactions combine light atomic nuclei such as hydrogen to form heavier ones such as helium, producing energy.

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