Abstract
The dynamics of electron beam ablation plumes have been characterized through the application of dye laser resonance absorption photography. The ablation of fused silica by a channelspark electron beam was studied by probing the near-ground state, 3p(2) D-1-4s P-1(0) neutral Si transition at 288.158 nm. Necessary background gases (Ar or N-2) were tested at pressures of 15 or 30 mTorr. A two-lobed, Si atom plume shape was discovered that is hydrodynamically more complex than laser ablation plumes. These plumes merge into a single-lobed plume at about 400 ns after the e-beam current pulse rise. Plume front expansion velocities of Si atoms were measured at nearly 1 cm/mu s, and are comparable to the expansion of laser ablated metal atom plumes with laser fluences of a few J/cm(2). (C) 1998 American Institute of Physics. [S0003-6951(98)02444-9].