UKAEA Journals

Showing 1 - 5 of 5 Journals Results

A new infrared Thomson scattering system has been designed for the MAST tokamak. The system will measure at 120 spatial points with 10 mm resolution across the plasma. Eight 30 Hz 1.6 J Nd:YAG lasers will be combined to produce a sampling rate of 240 Hz. The lasers will follow separate parallel beam paths to the MAST vessel. Scattered light will b…


A new edge Thomson scattering diagnostic has been implemented at MAST to complement an existing high spatial resolution ruby laser system and the high time sampling core Nd:YAG system. The Nd:YAG system comprises of four independently controllable lasers. Scattered light from these lasers is viewed at large scattering angle 153° by a special optic…


Both ruby laser ( 300 points ) and NdYAG laser ( 19 points ) Thomson scattering systems are used on MAST. Fast nonlinear optical switching shunts laser beams from the four 50 Hz NdYAG lasers to obtain coaxial plasma illumination. The technique allows for future expandability to many laser systems. The ruby laser system is used in parallel. A broadb…


Spontaneous transitions from the low ‘‘L-mode’’ to high ‘‘H-mode’’ of tokamak plasma confinement, first observed during neutral beam heating experiments on ASDEX, are now routinely achieved in many tokamak experiments. The H-mode regime is attractive as it offers the possibility of enhanced confinement, and thus a route towards a mo…


Electron Bernstein waves are analyzed as possible candidates for heating spherical tokamaks. An inhomogeneous plane slab model of the plasma with a sheared magnetic field is used to calculate the linear conversion of the ordinary mode (O-mode) to the extraordinary mode (X-mode). A formula for the fraction of the incident O-mode energy which is conv…