A parametric study of collisional and pulse attenuation on Raman threshold intensity in cluster plasmas

Abstract

Coulombic expansion of an atomic cluster can significantly affect the growth of stimulated Raman backscattering in cluster embedded plasmas. The pulse attenuation and the collisional absorption occur during the early phase of cluster expansion, competing against each other in determining the Raman threshold intensity in a cluster plasma. The threshold laser intensities estimated for various wave numbers of the electron plasma waves are found to be consistent with the previous result [P. K. Tiwari et al., Phys. Plasmas 14, 103101 (2007)]: Collisional threshold intensities are to be of 1 similar to 10(5) W/cm(2) at the electron-ion collisional frequency similar to 10(13) s(-1), and the pulse attenuated threshold intensities are to be of similar to 10(13) W/cm(2) for short pulse length similar to 20 fs. The pulse attenuation and collisional absorption of Raman threshold intensities are found to be inversely proportional to both the pulse duration and attenuation length. (C) 2008 American Institute of Physics.