The excitation mechanism of buffer gas in the laser-ablation process was investigated by time- and space-resolved emission spectroscopies. A silicon disk was ablated in neon gas at a pressure of 1 torr by the fundamental beam output of a Nd: yttrium aluminum garnet laser (1064 nm). The time-resolved emission spectra showed the generation of excited silicon ions Sin+*(n=1-3) and excited neon neutrals Ne-* to the 2p(1) level immediately after laser irradiation. Excitation of Ne to the 2p(n)(n=2-10) levels was delayed by 150 ns. The temporal evolutions of the space-resolved emission from Ne-* indicated excitation by fast (< 100 ns) and/or slow (< 300 ns) processes. The slow process contributed to all 2p(n) levels, while the fast process was observed only in excitation to the 2p(1) level. This means that the fast process involves level-selective excitation. Based on temporal evolutions, the energy levels, and the collision cross sections of Ne and Sin+, we assigned the fast and slow processes to excitations by electronic-to-electronic energy transfer from Si2+* and translational-to-electronic energy transfer from Si+, respectively. (c) 2005 American Institute of Physics.