Coulomb Explosion Dynamics Of Cyclic Hydrocarbon Molecules In Femtosecond Laser Fields

The molecular dissociation and Coulomb explosion dynamics generated by the interaction of strong femtosecond lasers,and molecules have long been one of the hot spots in the field of strong field atomic and molecular physics.The ion momentum distribute obtained by dissociation and Coulomb explosion can not only provide molecular fragmentation mechanism.In this paper,the fragmentation and Coulomb explosionprocessesofthreemolecules,Benzenne?C₆H₆?;Cyclohexene(C₆H₁₀);Cy-clohecane(C₆H₁₂),after the femtosecond laser irradiation,are compared and studied in detail.The three molecules have similar geometric structure.However,the chamical bond components are quite different,so we can explore the effect of different bond types on the Coulomb explosion of the ring organic molecules as our experimental subjects.The dissociation and Coulomb explosion dynamics of benzene,cyclohexene and cyclohexane in the laser field were studied in detail in the experiment by using the COLTRIMS device and the laser with a central wavelength of 800 nm and a pulse duration of 35 fs,combined with the ion-ion coincidence measurement technology.Three molecular Time-of-flight mass spectra were extracted,and a series of comprehensive experimental data,such as Coulomb explosion channel resolution,fragment subchannel yield,3D momentum distribution and so on,were extracted.Through the coulomb explosion ion momentum distribution obtained from two-dimensional angular distribution and energy distribution of ions,calculation of the highest occupied molecular orbital HOMO distribution according to the experimental data obtained under different conditions are analyzed according to the theory of,and the experimental basis is provided for further study of the ionization/dissociation ultrafast kinetic process of annular organic molecules.For complex molecules,due to the complexity of structure and theoretical calculation on the more difficult to deal with factors such as,in ultrafast dynamics theory and experimental study is less,so in terms of the complicatedness polyatomic molecule system also needs continuous development.When comparing the mass spectra,we observed that the degree of fragmentation of benzene was relatively small compared with that of the other two molecules,which indicated that the benzene molecule itself was stable and not easy to dissociate in the strong field.On ion fragments momentum distribution and angular distribution found in the comparison and analysis of,cyclohexane and benzene molecules fragments of the coulomb explosion product ion momentum distribution and angular distribution trend is isotropic,roughly and cyclohexene,a maximum in about 75^°,in 90^°there was a minimum,the key reason is the structure of the cyclohexene itself,in the process of electrolytic dissociation from the near a carbon???,a carbon???between the electron orbital has caused by impact.At the same time,we in the extraction of three molecules produced by the coulomb explosion KER?Kinetic energy Release?,it found that two coulomb explosion of cyclohexene channel KER peak are less than the other two kinds of molecules,and the yield of the coulomb explosion channel ion fragments,validated our above ideas.For benzene,cyclohexene,cyclohexane three molecules in intense laser field dynamics research,can help us to ring on dynamic behavior of the organic molecules have a new understanding,a more in-depth understanding of the electron cloud distribution inside the molecule to molecule ionization rate of settlement from the influence of the path.