Time evolution of colliding laser produced magnesium plasmas investigated using a pinhole camera

Time resolved studies of colliding laser produced magnesium plasmas are performed using a pinhole camera. A ruby laser pulse is split into two beams using a movable glass wedge and focused onto a planar target or targets placed at 90 degrees to each other. A gated pinhole camera provides an orthogonal view of the collision. Measurements with an aluminum filter allowed identification of soft x-ray production zones. A good interpenetration of the two plasmas was observed in the 90 degrees target geometry, because of higher relative velocities, than in the case of laterally colliding plasmas. The appearance of the collision region depended strongly on the power density and on the separation of the foci on the target surfaces. (C) 2001 American Institute of Physics.