Magnetic vapor shielding mechanism in electromagnetic and electrothermal launchers

The vapor shield formed by the ablation of wall materials in plasma-driven launchers absorbs a large fraction of the incoming energy and reduces the surface erosion. Decreasing the turbulent energy transport through the vapor shield may result in further reduction of the surface erosion. Applying a strong magnetic field parallel to the surface (magnetic vapor shield) is a possible approach. SIRENS, an electrothermal launcher, is equipped with a pulsed high intensity magnet, and has been used to investigate the magnetic vapor shield effect. The magnetic field has been applied at different field intensities (2.6 to 8.75 T), for launcher input energy varying from 1 to 5 kJ. A 25-35% reduction of the surface ablation has been achieved at 6.25 T for energy inputs of 1-2 kJ, with a trend of further reduction at higher values of the magnetic field