The PROTO-SPHERA experiment is an unconventional magnetic confinement scheme,
which aims at producing a Spherical Torus (with Ie≤300 kA) around a Plasma Centerpost (with Ie=70 kA) fed by electrodes of annular shape, in contrast with the metal centerpost of conventional Tokamaks. The Phase-1 of PROTO-SPHERA, aimed of obtaining a stable Hydrogen Plasma Centerpost, lasting 1 sec at Ie=8.5 kA...
PROTO-SPHERA is an axi-symmetric magnetic confinement experiment, just like a spherical Tokamak: toroidal and poloidal magnetic fields (i.e. a plasma toroidal current IST) are required inside a spherical torus to contain the plasma. PROTO-SPHERA produces both fields while removing the two central metal conductors: the central toroidal rod and the central ohmic transformer; they are replaced by...
The PROTO-SPHERA experiment can produce plasma spherical tori with a simply connected configuration (the centerpost is practically implemented by the plasma itself) and a high confinement efficiency (β→1). Such configurations are obtained from the self-organization of a plasma arc (screw pinch) in a magnetostatic field. This approach leads to several technical and economic advantages, that...
Plasma tori formed around a 10 kA centerpost screw-pinch plasma discharge have been observed in phase-1 of PROTO-SPHERA experiments.
A simple model of plasma equilibrium has been developed, which reproduces the morphological features observed so far, in particular the bumpy shape of the centerpost discharge and the slim torus surrounding it.
The model is based on a generalization of the...
The first stage in the experimental programme of MAST-U is planned for late 2019. A modelling framework, using time-dependent vacuum field calculations, has identified viable direct induction scenarios on MAST-U that achieve suitable null quality for rapid breakdown combined with the requirements for plasma equilibrium and passive vertical stability during the early plasma current ramp up [1]....
Presentation on the features and status of MAST Upgrade
LTX-β, the upgrade to the Lithium Tokamak Experiment, has now been operated with full lithium coatings on all plasma-facing surfaces, and at increased toroidal fields >0.3 T. Plasma current has so far been limited to <100 kA. The upgrade includes a neutral beam injector provided by Tri-Alpha Energy Technologies. The beam is designed to operate at 20 kV, with 35A of ion current. So far >600 kW...
