Patterson James E, Dreger Zbigniew A, Miao Maosheng, Gupta Yogendra M
Institute for Shock Physics and Department of Physics, Washington State University, Pullman, Washington 99164-2816, USA.
J Phys Chem A. 2008 Aug 14;112(32):7374-82. doi: 10.1021/jp800827b. Epub 2008 Jul 22.
Time-resolved optical spectroscopy was used to examine chemical decomposition of RDX crystals shocked along the [111] orientation to peak stresses between 7 and 20 GPa. Shock-induced emission, produced by decomposition intermediates, was observed over a broad spectral range from 350 to 850 nm. A threshold in the emission response of RDX was found at about 10 GPa peak stress. Below this threshold, the emission spectrum remained unchanged during shock compression. Above 10 GPa, the emission spectrum changed with a long wavelength component dominating the spectrum. The long wavelength emission is attributed to the formation of NO2 radicals. Above the 10 GPa threshold, the spectrally integrated intensity increased significantly, suggesting the acceleration of chemical decomposition. This acceleration is attributed to bimolecular reactions between unreacted RDX and free radicals. These results provide a significant experimental foundation for further development of a decomposition mechanism for shocked RDX (following paper in this issue).
采用时间分辨光谱法研究了沿[111]取向冲击至7至20 GPa峰值应力的RDX晶体的化学分解。由分解中间体产生的冲击诱导发射在350至850 nm的宽光谱范围内被观测到。发现RDX的发射响应在约10 GPa峰值应力处存在一个阈值。低于该阈值时，发射光谱在冲击压缩过程中保持不变。高于10 GPa时，发射光谱发生变化，长波长成分主导光谱。长波长发射归因于NO2自由基的形成。高于10 GPa阈值时，光谱积分强度显著增加，表明化学分解加速。这种加速归因于未反应的RDX与自由基之间的双分子反应。这些结果为进一步发展冲击RDX的分解机理提供了重要的实验基础（本期后续论文）。
