Helicon plasma in a magnetic shuttle

Helicon plasma immersed in such a magnetic shuttle (mirror ratio 5) that can provide the confnement of charged particles is modeled using an electromagnetic solver. The perpendicular structure of the wave feld along this shuttle is given in terms of stream vector plots, showing a signifcant change from midplane to ending throats, and the vector feld rotates and forms a circular layer that separates the plasma column radially into core and edge regions near the throats.

The influences of the driving frequency (f = 6.78 MHz–40.68 MHz), plasma density (nemax = 1016 m-3 to 1019 m-3), and feld strength (B0max = 0.017 T–1.7 T) on the wave feld structure and power absorption are computed in detail. It is found that the wave energy and power absorption decrease for increased driving frequency and reduced feld strength and increase signifcantly when the plasma density is above a certain value.