  The ideal invariants present in the formalism of magnetohydrodynamics (MHD),
i.e. global quantities that are conserved in the absence of sources and
dissipative effects, play an important role in various theoretical and
numerical studies of MHD turbulence. The fluxes of these ideal invariants
represent separate channels that transfer the information across different
scales in a turbulent system. Once a statistically stationary state of
turbulence is reached, the amount of any ideal invariant quantity introduced in
the system by a forcing mechanism equals the amount of the same quantity
removed by the dissipative effects from the system. For highly developed
turbulence, these two mechanisms act predominantly at different scales that are
largely separated. Since the ideal invariant quantities cascade between scales,
a constant flux is generated with great implication on the state of the system.
Numerically, controlling the ideal invariant fluxes levels for a turbulent MHD
system is important for the analysis of fundamental MHD turbulence properties.
We propose a forcing mechanism that controls the three ideal invariants of MHD
turbulence: the total energy, the cross-helicity and the magnetic helicity.
This forcing is implemented in the freely available TURBO solver, that is also
briefly presented.
