TECHNICAL ASPECTS AND STATUS OF THE SPANISH STELLARATOR TJ-II

Abstract TJ-II is a medium-size stellarator of the heliac-type being under construction in Madrid, Spain. The project was granted EURATOM preferential support phase II in November 89 and is expected to start operation in 95. This device allows the exploration of a wide range of magnetic configurations. The rotational transform can be varied from 0.9 to 2.5. Shear variation is possible up to 10%. Theory predicts maximum beta values as high as 6%. The average major plasma radius is 1.5 m. The minor dimensions of the bean-shaped plasma are approximately 0.4 m by 0.2 m. Toroidal field: 1T. Pulse length: 0.2 s to 1 s. Pulse break: 5 min. Auxiliary heating: 400 kW ECRH at 53.2 GHz in stage I; 2 MW NBI will be added in stage II. In stage III 4 MW NBI heating is planned to be applied. The paper gives an overview on the technical features of the experiment, describes the main aspects of the recent engineering work and presents the status of the device.