Effects of magnetic field on laser-generated plasma

A laser-generated plasma in vacuum was placed in an axial magnetic field directed along the normal to the target surface. The laser beam intensity, of the order of 1010W/cm2, was obtained by a Nd:Yag operating at 1064nm wavelength, 9ns pulse width, and 300mJ pulse energy. Time-of-flight measurements of ion emission were performed along the direction normal to the target surface by using an ion collector at different target distances. Investigations were performed ablating a lot of metallic elements and applying a permanent 0.1Tesla magnetic field. An electron magnetic trap, placed in front of the target surface, acts so as a negative charge cloud, which accelerates and deflects the ions ejected from the plasma. Results demonstrate that the magnetic field trap modifies the electron charge density in front of the target surface inducing an ion focalization, increasing the ion velocity, the mean ion charge state, and the ion current.