Quantitative correlation between facets defects of RDX crystals and their laser sensitivity

[Display omitted] •{210} facets of RDX crystals with different surface qualities are fabricated.•355nm laser sensitivity of RDX evolves exponentially with surface defects sizes.•Laser-induced micro-explosion is more probable to take place near micro-defects.•Defects-sensitivity correlations can be well explained by 3D FDTD simulations. In this work, the {210} facets of cyclotrimethylenetrinitramine (RDX) single crystals with different quality were studied by scanning electron microscopy and atomic force microscopy. Their laser sensitivity was then assessed using a direct laser ignition test irradiated with ultraviolet laser (wavelength: 355nm, pulse width: 6.4ns). Quantitative relationships between laser sensitivity and surface defects of RDX (210) and (2¯1¯0) facets were investigated. It is determined that the laser sensitivity exhibits significant correlation with the surface roughness, size of which is comparable with scales of laser wavelength. 3D FDTD simulations disclose that this relationship can be well explained with light intensity modulation effects induced by micro-defects on the initial plane wave.