History
The flexible Heliac TJ-II was designed on the basis of calculations performed by the team of physicists and engineers of CIEMAT, in collaboration with the Oak Ridge National Laboratory (ORNL, USA) and thePrecedents
TJ-II is the third magnetic confinement device in a series. In 1983, the device TJ-I was taken into operation. The denomination of this device is due to the abbreviation of "Tokamak de la Junta de Energía Nuclear", this being the former denomination of CIEMAT. The abbreviation was maintained for successive devices for administrative reasons. In 1994, the torsatron TJ-IU was taken into operation. This was the first magnetic confinement device entirely built in Spain. Currently, TJ-IU is located at the University of Stuttgart in Germany under the name of TJ-K (the 'K' stands for Kiel, its first location in Germany, before arriving in Stuttgart).Description
In TJ-II, the magnetic trap is obtained by means of various sets of coils that completely determine the magnetic surfaces before plasma initiation. The toroidal field is created by 32 coils. The three-dimensional twist of the central axis of the configuration is generated by means of two central coils: one circular and one helical. The vertical position of the plasma is controlled by the vertical field coils. The combined action of these magnetic fields generate bean-shaped magnetic surfaces that guide the particles of the plasma so that they do not collide with the vacuum vessel wall.Parameters
It is a four period low magnetic shearGoals and Research
The objective of the experimental program of TJ-II is to investigate the physics of plasma in a device with a helical magnetic axis having a great flexibility in its magnetic configuration, and to contribute to the international effort regarding the study of magnetic confinement devices for fusion.Experiment
* Transport and magnetic configuration, iota effects * Confinement transitions, zonal flows * Internal Transport Barriers * Plasma Wall Interaction (in 2008 it experimented withTheory
* Neoclassical transport * Self-Organised Criticality * Non-diffusive transport * Gyrokinetic simulations * Divertor studies for TJ-II * Topology and transport (research project funded by the Ministerio de Ciencia e Innovación)Diagnostics development
References
Further reading
*FusionWiki, jointly hosted by LNF and Fusenet http://wiki.fusenet.eu/wiki/TJ-IIExternal links