Dynamics of laser produced carbon plasma expanding in low pressure ambient atmosphere

Abstract

The laser produced carbon plasma expanding in vacuum (P< 10-3 Torr) and low pressure ambient atmosphere (P< 10-2 Torr and P= 10-1 Torr) has been studied by emission spectroscopy and fast photography using intensified charged coupled device (ICCD). The double peak structure is observed in the temporal profile of C I transition 2p33D0-8f F (5/2) at 399.7 nm, C II transition 3d 2D-4f 2F0 at 426.7 nm, and C III transition 3s 3S-3p 3P0 at 465.0 nm as the plasma expands in ambient atmosphere. The stratification of the plasma into slow and fast components is imaged using ICCD. A compression wave model is proposed to explain the occurrence of a double peak structure. © 1998 American Institute of Physics.