Penetration of a compressible magnetized plasma object into a low beta target plasma

The effects of the shape and compressibility of a perfectly conducting sphe romaklike compact toroid (SCT) propagating into a low beta plasma have been studied. Simple tools that allow one to identify conditions for the optimu m penetration of the SCT into the low beta target plasma have been develope d. The main results obtained are (1) squeezed (prolate) SCT's penetrate mor e easily; (2) including SCT compressibility reduces injection power require ment, and (3) there exists a broad parameter range where the SCT injection can maintain tokamak particle inventory while simultaneously reducing exter nal auxiliary heating requirements. (C) 1999 American Institute of Physics. [S1070-664X(99)03105-5].