a = inner radius of coil, m b = outer radius of coil, m B,Br = radial magnetic field, T C = capacitance of storage bank, F E9 = azimuthal electric field, V/m Fz = axial force, N g = acceleration of gravity, m/s Ij = circuit current, A I2 = plasma current, A Isp = specific impulse, s je = plasma current density, A/m js = surface current density, A/m L = circuit inductance, H Le = external (parasitic) inductance, H Lf = initial circuit inductance, H L0 = coil inductance unloaded, H £ == stroke length, m M = mutual inductance, H m = plasma mass, kg m0 = total injected mass, kg p = power, W R = resistance per square of plasma, 12 r = radial coordinate, cm Re — external circuit resistance, 0 Rm = magnetic Reynolds number Rp = resistance of plasma loop, ft / =time, s t0 = time equivalent of d0, s Te = electron temperature, eV UR = energy loss to plasma resistance, J Up = work done on plasma, J v = plasma velocity, m/s V0 = initial capacitor voltage, V z = axial coordinate, cm Z = axial position of current, m Z0 = decoupling distance of plasma, m A/ = impulse per discharge, N s AL = change in circuit inductance, H B = azimuthal coordinate, deg <5 = thickness of current sheet, m <5Z = depth of initial gas layer, m d0 = initial thickness of current sheet, m r? = efficiency of thruster