Low frequency lattice mode dynamics of cyclotrimethylene trinitramine (RDX) crystal studied by femtosecond time-resolved impulsive stimulated Raman scattering

The femtosecond time-resolved impulsive stimulated Raman scattering (fs-ISRS) has been performed to study the low frequency lattice mode dynamics of the RDX crystal. Through Fourier filtering, four lattice mode dynamics is distinguished from the time-resolved spectrum. And the wavenumbers and time constants of these four lattice modes are determined by fitting their dynamic curves. The energy dispersion paths of these four lattice modes are deduced from these fitting parameters. Compared with the other three lattice modes, the lattice mode with wavenumber 30 cm^-1 has a very longer life time. We consider that the excitation of this lattice mode more likely to cause the damage of the intermolecular interaction under the strong external stimulation.