Inductive field-reversed configuration accelerator for Tokamak Fueling

Compact toroids can be used for fueling other fusion devices by acceleratin g them to high enough velocities to penetrate strong magnetic fields. In th e simplest analysis, the kinetic energy density of a flux-excluding object 1/2 rho v(2) must exceed the magnetic field energy density B-2/2 mu(0) Of t he field to be pushed aside. Field reversed configurations (FRCs) are a typ e of compact toroid that are particularly efficient for this application du e to their high density and thus lower required energy per unit mass. FRCs are also formed and accelerated inductively, thus minimizing possible impur ity contamination. The Tokamak Refueling by Accelerated Plasmoids (TRAP) ex periment was built to develop the inductive acceleration method and test th e ability of high-velocity FRCs to penetrate transverse magnetic fields. Si mple models have been 'developed for both the acceleration and penetration processes to determine fueler parameters required for a given tokamak field . Experimental results are given for the acceleration process. Half-milligr am FRCs with number densities of 10(22) m(-3) were accelerated to velocitie s of 200 km/s, sufficient to fuel tokamaks with Tesla magnetic fields. The technology is easily extendable to much higher FRC densities and velocities , sufficient to fuel the largest highest-field tokamaks.