Kiel 2004 – scientific programme

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P: Plasmaphysik

P 10: Postersitzung: Niedertemperaturplasmen Plasmatechnologie II, Staubige Plasmen II, Magnetischer Einschluss II

P 10.6: Poster

Tuesday, March 9, 2004, 17:45–19:30, Foyer

ECR heating in a helicon device — •Jacob Zalach, Ramin Madani, Olaf Grulke, and Thomas Klinger — EURATOM Assosiation, Max-Planck-Institut für Plasmaphysik, Teilinstitut Greifswald, D-17491 Greifswald

Helicon plasma sources are attracting a great research interest due to the efficient use of rf power. High densities can be achieved with only a few kW of rf power. In our device a helicon plasma with densities of up to 10¹⁹ m⁻³ is created. Nevertheless, the electron temperatures in helicon plasmas are generally low and in the range of only 2 to 5 eV. The combination of high plasma density and low electron temperature, leads to a highly collisional plasma in which Coulomb collisions are dominant. If under these circumstances the collisionality is reduced, due to higher electron temperature, one could expect to observe electromagnetic drift wave phenomena. In this work, an additional ECR heating to the helicon plasma is realised through the installation of a microwave device opposite the helicon source. The VINETA device is 4.5 m long and is operated at 5 kW maximum rf power. The plasma is confined by a linear magnetic field of up to 100 mT. A right-hand circularly polarised wave at 2.45 GHz is fired against a background helicon plasma. The configuration of the coils can be adjusted easily to accommodate the resonant absorption and the effective coupling of the microwave along the ambient axial magnetic field. First diagnostic studies on changes to the collisionality by additional ECR heating are presented.