The need of using anomalous resistivity due to Lower Hybrid Instabilities in plasma-magnetic field interfaces

Anomalous plasma can arise in dense plasmas as a consequence of the develop ment resistivity of the Lower Hybrid drift Instability (LHI), which is trig gered whenever the electron drift velocity becomes comparable to or larger than the thermal ion velocity. This effect was carefully evaluated for thet a-pinch plasmas and later on used in the modelling of denser pinches, like Plasma Focus columns or Z-pinches, because of the diverging electron drift velocity expected in the classical equilibrium (uniform current, parabolic plasma density) pinch. Conceptually, the possibility of diverging drift vel ocities is far more a general situation than Z-pinches, and in this work we study it, in general, for plasma-magnetic field interfaces existing in oth er configurations, like that found in devices producing travelling current sheets (Plasma Focus devices, imploding pinches, etc.). We show that it is essential to account for this effect in steady state situations, and that i t could be also important in the time varying ones.