Design of magnetic configurations for the linear plasma device LEAD.

A new linear plasma device LEAD (Linear experimental advanced device) has been built in Southwest Institute of Physics (SWIP) in China. One of the most notable features of LEAD is the highly flexible and customizable magnetic field configurations, such as highly-uniform field, convergent field, divergent field and cusp field. In this article, we present the design of the magnetic configurations, taking the topology of the magnets, the three-stage vacuum chamber and the magnetic requirements of plasma sources into account. The interplay between the magnetic shielding box of the matching network and the main magnetic field inside the vacuum chamber is evaluated to ensure both a tolerable influence on main magnetic field and an effective magnetic shielding for the automatic impedance matching box in helicon source. [ABSTRACT FROM AUTHOR]