The simulations of three-dimensional particle dynamics show that when irradiated by an ultrashort intense laser pulse,the deuterated methane cluster expands and the majority of deuterons overrun the more slowly expanding carbon ions,resulting in the creation of two separated subclusters.The enhanced deuteron kinetic energy and a narrow peak around the energy maximum in the deuteron energy distribution make a considerable contribution to the efficiency of nuclear fusion compared with the case of homonuclear deuterium clusters.With the intense laser irradiation,the nuclear fusion yield increases with the increase of the cluster size,so that deuterated heteronuclear clusters with larger sizes are required to achieve a greater neutron yield.
An experimental investigation of the length and resistance of the laser plasma channelgenerated by filamentation of fs laser pulses in air was presented. It was found that the lengthof the plasma channel was different from that of the laser filament. This phenomenon was commensuratewith a special self-guide mechanism without ionization. Through increase of the laserenergy the plasma channel could be prolonged and the resistance could be reduced. To get evenlower resistance, more effective control would be needed over the multi-filament. The lifetime ofthe plasma channel was increased by a factor of 4.5 by pulse sequences, which were generated bydetuning the regenerative amplifier in the chirped pulse arnplification (CPA) laser system.
