A type of plasma accelerator is proposed in which the plasma is confined in a magnetic field in the form of an accelerating cusp, the confinement resulting from the combined action of the magnetic field and the equivalent gravitational field of the acceleration. The accelerating cusp is produced by a transient wave on a suitable transmission line of constant characteristic impedance and increasing velocity of propagation. Such a transmission line is in the form of a tapered solenoid suitably loaded with distributed capacitance to preserve constant characteristic impedance. An order-of-magnitude calculation ofthe performance ofsuch a line is made and it is found that a line 3 meters long with a characteristic impedance of 12.6 ohms and an applied voltage of 300 kV can accelerate 1017 deuterons to 50 keV energy. Several possible experiments on the confinement of hot plasmas using such an accelerator are described.
Theoretical limitations to the Hall acceleration mechanism in the polytron machine