The photoionization of seeded benzene beam by 25 ns laser pulse at wavelengths of 266, 355 and 1064 nm has been studied by the time of flight mass spectrometry. The observed mass spectra at 266 nm and 355 nm at intens...The photoionization of seeded benzene beam by 25 ns laser pulse at wavelengths of 266, 355 and 1064 nm has been studied by the time of flight mass spectrometry. The observed mass spectra at 266 nm and 355 nm at intensities of 10 10 ~10 11 W/cm 2 indicate a multiphoton ionization and dissociation (MPID) process, in which C +, C 2H x +, C 3H x +, C 4H x + and C 6H 6 + are main products. While at 1064 nm laser of similar intensities, the domain ion is C 4+ which is produced from Coulomb explosion. The longer wavelength facilities the energy absorption rate during inverse bremsstrahlung, which leads to the resulting wavelength dependence of the multicharged atomic ions.展开更多
文摘The photoionization of seeded benzene beam by 25 ns laser pulse at wavelengths of 266, 355 and 1064 nm has been studied by the time of flight mass spectrometry. The observed mass spectra at 266 nm and 355 nm at intensities of 10 10 ~10 11 W/cm 2 indicate a multiphoton ionization and dissociation (MPID) process, in which C +, C 2H x +, C 3H x +, C 4H x + and C 6H 6 + are main products. While at 1064 nm laser of similar intensities, the domain ion is C 4+ which is produced from Coulomb explosion. The longer wavelength facilities the energy absorption rate during inverse bremsstrahlung, which leads to the resulting wavelength dependence of the multicharged atomic ions.