Measurements of the toroidal plasma rotation velocity in TFTR major-radius compression experiments with auxiliary neutral beam heating

Abstract

The time history of the central toroidal plasma rotation velocity in ToUamak Fusion Test Reactor {TFTR) experiments with auxiliary heating by neutral deuterium beam injection and major-radius compression has been measured from the Doppler shift of the emitted TiXXI-Ka line radiation. The experiments were conductect for neutral bean powers in the range from 2.1 to 3.8 MW and line-averaged densities in the range from 1.8 to 3.0 x 10 1^ m -2 .The observed rotation velocity increase during compression is in agreement with results from modeling calculations which assume classical slowing-down of the injected fast deuterium ions and momentum damping at the rate established in the precompression plasma.

Geodesic acoustic modes and zonal flows in rotating large-aspect-ratio tokamak plasmas

“…However, tokamak equilibria with essential mass flows may exist. Toroidal plasma velocities comparable to the sound velocity have been reached in experiments in both large-aspect-ratio and spherical tokamaks with neutral beam injection (see, e.g., [9,10]).…”

“…It is obvious from equation (11) that B 0 • ∇φ = 0, which means that the electrostatic potential is constant on the magnetic surface, φ = φ(ψ). Taking into account equation (9), we obtain the flow velocity…”

Rest-wavelength fiducials for the ITER core imaging x-ray spectrometer

“…This means that the position of the 3D line will be determined within an accuracy of about 10 −5 Å, i.e., similar to what was achieved on TFTR. 1 . In order to determine the position of the Ir line to within one part in 10 5 , i.e., to within 100th of the line width or about 10 −5 Å, one also roughly needs 10 000 counts.…”