PRODUCTS

PLUME DYNAMICS OF LASER PRODUCED PLASMA

Plume dynamics of pulsed laser ablated aluminium in ambient nitrogen pressure varying from 0.01 to 70 Torr was investigated using an Andor Istar ICCD at IIT, Kanpur. At pressure of 0.0 to 1 Torr plasma expansion followed shock model whereas at 10 and 70 Torr plasma expansion followed drag model. the difference in the values of vapour and shock temperatures calculated at 0.1 Torr and 70 Torr has been used to understand the formation of AIN in vapour phase. At pressures >= 1 Torr and later times plasma - gas interface showed instability in the leading edge of the expanding plume attributed to Rayleigh-Taylor instability.