Up to Kr 17+ multicharged krypton ions have b ee n observed in time-of-flight mass spectrum by a 25 ns Nd-YAG 1.064 μm laser at laser intensity about 10 12 W/cm 2. Experimental results indicate that the multicharged ...Up to Kr 17+ multicharged krypton ions have b ee n observed in time-of-flight mass spectrum by a 25 ns Nd-YAG 1.064 μm laser at laser intensity about 10 12 W/cm 2. Experimental results indicate that the multicharged ions appear only when the laser interacts with the middle part of the pulsed beam,and the intensities of the multicharged ions increase dramat ically by increasing the backing pressure of Kr gas, which indicates that the cl usters in the beam is essential to the production of multicharged ions. From the experimental results, it is concluded that the cluster is ionized via multiphot on ionization and forms a nanoplasma ball,which can absorb the laser resonantly to further ionize the single charge ion to the high charge state.展开更多
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Up to Kr 17+ multicharged krypton ions have b ee n observed in time-of-flight mass spectrum by a 25 ns Nd-YAG 1.064 μm laser at laser intensity about 10 12 W/cm 2. Experimental results indicate that the multicharged ions appear only when the laser interacts with the middle part of the pulsed beam,and the intensities of the multicharged ions increase dramat ically by increasing the backing pressure of Kr gas, which indicates that the cl usters in the beam is essential to the production of multicharged ions. From the experimental results, it is concluded that the cluster is ionized via multiphot on ionization and forms a nanoplasma ball,which can absorb the laser resonantly to further ionize the single charge ion to the high charge state.
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.
