The role of sub-target in the transversely excited atmospheric pressure CO2 laser-induced shock-wave plasma

A transversely excited atmospheric pressure (TEA) CO2 laser pulse (50mJ, 10 0ns) was focused on silicon grease which is painted on a copper plate as a subtarget with a power density of 6 GW/cm(2) under reduced pressure, The co mparison of the characteristics of the induced laser plasma between two cas es, with subtarget and without subtarget was made. It is proved that the em ission spectrum assigned to the silicon atom can be detected only for the c ase with the subtarget. It is also proved that in the absence of the subtar get, the gushing speed of the atom is very low, while for the case with sub target, the gushing speed of atoms becomes very fast. It is shown that the setting of subtarget is very effective for producing laser-induced shock wa ve plasma and it is very effective for the realize quantitative analysis of a soft material.