Mass spectroscopic study of the chemical reaction zone in detonating liquid nitromethane

We report a time-of-flight mass spectroscopic study of the chemical reaction zone in base-sensitized detonating liquid nitromethane (NM-CH3NO2). Mass spectra of the reaction zone region are presented for cases where the CH3NO2, (CH3NO2)-C-13, and CD3NO2 forms of NM were detonated. In experiments in which detonation was made to occur, the detonation process was initiated by a slapper detonator system. The NM explosives were confined in steel, and the charge geometry was chosen such that the detonations were traveling steadily by the time the detonation wave reached the end of the charge. Various nondetonation control experiments were also performed and are described. Two-dimensional numerical fluid-dynamic computations that mimic the experimental system were performed in order to help in the interpretation. We estimate that, for the base-sensitized NM explosive used, the steady two-dimensional chemical-reaction zone is ca. 50 mu m in spatial extent and has a time duration of ca. 7 ns. The most important result obtained is that the new chemical species that are observed in the reaction zone are the result of condensation reactions where two or more Nhl molecules combine to form molecules more massive than NM or produce molecules in which numerous nitrogen atoms are present. A brief review of earlier work on this problem is presented to aid readers in understanding the new results.