TORE SUPRA

Figure 1:TORE SUPRA - Cadarache

The history of TORE SUPRA
TORE SUPRA Parameters
TORE SUPRA Milestones
TORE SUPRA Objectives

The history of TORE SUPRA

The EURATOM-CEA Association covers the essential part of the range of activities required to progress towards the definition of a controlled thermonuclear fusion power plant. The main experiment of the Association is the TORE SUPRA tokamak, which started construction at Cadarache (France) in 1982 - at the same time as the tokamaks TFTR (Princeton, USA) and JET (Culham, UK) started operation - to study plasmas in quasi steady state operation. TORE SUPRA is one of the largest tokamaks operating today and was the first one which used a series of superconducting toroidal coils spaced around the torus wall to generate a strong permanent toroidal magnetic field.
The first plasma was reached in TORE SUPRA in April 1988. Since that time the superconducting magnet worked quasi without interruption. This represents a significant technological success and an important progress for the feasibility of the programme of controlled thermonuclear fusion.
In 1996 a record was reached with a plasma duration of two minutes with an induced current of almost 1 million amperes generated non inductively by 2.3 MW of lower hybrid frequency waves (i.e. 280 Mjoules of injected and extracted energy). This result was possible due to the actively cooled plasma facing components installed in the machine from the beginning.
This result opened the way to the active control of steady state plasma discharges and the associated physics. The search for enhancement of performances has triggered new technological developments for plasma facing components (CIEL project) and non inductive current drive by electromagnetic waves (CIMES project). The new CIEL configuration has been implemented in 2002 and the CIMES project will be progressively implemented between 2003 and 2005.
On 30th July 2002 a new world record was reached, thanks to the new CIEL configuration. A plasma discharge of 3 and a half minutes was achieved with an energy production of 600 Mjoules.
The results of TORE SUPRA and their international acceptance are an important input for the realization of the ITER project and the preparation of the first energy producing power plant DEMO.

Figure 2:TORE SUPRA Inside

TORE SUPRA Parameters

Plasma Major Radius (R)	2.25 m
Plasma Minor Radius (a)	0.70 m
Toroidal magnetic field (plasma center)	4.5 T
Maximum magnetic field in conductor	9.0 T
Mean diameter of a toroidal field coil	2.4 m
Plasma Current (I)	1.7 MA
Pulse length (inductive only)	30 s
Volt-seconds to drive plasma current	15 Vs

Figure 3:sketch of tore supra

TORE SUPRA Milestones

1977	Conceptual design of Tore Supra.
1980	Toroidal Field Model coil testing.
1981	Decision to launch the Tore Supra project.
1982-86	Manufacture of main components.
1986-88	Machine assembly.
1988	First plasma production (April).
1988	Failure of one superconducting coil (July).
1989	Repair of superconducting coil.
1990-95	Optimization of components for long pulse operation.
1995-96	Long pulse plasma shots.
1997-2002	Preparation of a second generation of plasma facing components (CIEL project).
2002	Operation in the CIEL configuration & upgrading of current drive power (CIMES project). Achievement of world record in plasma discharge: 3.5 minutes with 600 M Joules.

Figure 4:TORE SUPRA

TORE SUPRA Objectives

The purpose of TORE SUPRA is to obtain long stationary discharges, thus addressing two major questions: non-inductive current generation and continuous heat and particles removal. The physics programme therefore has two principal research orientations, complemented by studies on Magnethydrodynamic (MHD) stability, turbulence, and transport.
The first physics programme concerns the interaction of electromagnetic (Lower Hybrid and Ion Cyclotron) waves with the hot central plasma. All or part of the plasma current can be generated in this manner, thus controlling the current density profile. This is an important contribution to the concept of an "advanced tokamak". In 1996 notable progress has been made, allowing totally non-inductive shots over a period of 75 s to be obtained.
The second physics programme concerns the edge plasma and its interaction with the first wall.
One originality of TORE SUPRA is the ergodic divertor, which perturbs the magnetic field at the plasma edge by creating a chaotic magnetic field region, resulting in outfluxes of hot plasma collected on neutralizers. Highly radiative layers have been obtained with this device, while preserving a good particle extraction capacity.

Figure 5:TORE SUPRA Plasma

Some noteworthy technological developments in TORE SUPRA include the injection of 9 MW at the ion cyclotron frequency with three antennas and 5 MW at the lower hybrid frequency with two "grills", and the development of prototypical components capable of extracting 15 MW/m2 of convective heat.
Work on neutral beam injection permitted the development of a negative ion source with characteristics approaching those required for ITER and the acceleration of negative ions lead to the production of a 60 mA beam of D- at 880 kV.