Steady-state Force Balance in the DEBS Code

V 2 A + C 2 s + V ∆t/∆x < 1 is satisfied, where VA is the Alfvén wave speed, Cs is the sound wave speed, and V is the flow speed. Unconditional stability for sound and Alfvén waves with arbitrary time step ∆t is achieved by adding a semi-implicit term to the momentum equation. However, the flow CFL condition V∆t/∆x <must still be satisfied. The resistivity and viscosity are advanced implicitly using fully forward time differencing. These equations can have steady state time-asymptotic solutions with finite flow [e.g., SH (single helicity) and/or QSH (quasi-single helicity) states in the RFP] that in the continuum satisfy the force balance condition