The Mechanism To Reveal SCB Plasma-primary Expolsives Interactions

It is important to reveal the mechanism of SCB (Semiconductor Bridge) plasma-primary explosives interactions for the design and development of the special sensitive explosives. The main contents in this paper include SCB plasma diagnosis, the response of primary explosives to SCB plasma, SCB ignition experiments for typical primary explosives, heat transfer model for SCB plasma, electron effects in the decomposition of primary explosives. The research contents and conclusions are as follows:The measurements of SCB plasma characteristic parameters were studied by the method of emission spectra and interference laser. Spatial size, diffusion speed, emission spectrum, electron density and temperature fluctuation over time for SCB plasma were obtained. The influence of SCB types and fring conditions to the SCB discharge process were discussed.The SCB ignition experiments for NHA (Nickel Hydrazine Azide), NHN (Nickel Hydrazine Nitric), LP (Lead Picric), LTNR (Lead Styphnic), BaTNR (Barium Styphnic) and LA (Lead Azide) were carried out. The primary explosive effect to the SCB discharging process was discussed. The conclusion is that the decomposition onset temperature and production affect the onset of SCB discharge and the duration of LTD, respectively.The heat transfer model for SCB plasma was established. The heat transfer effect due to the temperature gradient and the plasma sheath effect caused by electronic density were all analyzed in this model. The numerical results show that the heat transfer influence is predominate and the plasma sheath effect is subordinate for the smaller particle radius. The primary explosive particle with small radius, little thermal conductivity, low activation energy and large explosion heat favors for the low energy ignition according to the numerical results. The results were confirmed by the fring experiments.With the guide of the heat transfer model, the heat effect of SCB plasma was strengthened with the addition of Pb3O4 to LTNR by physical method. The physical mixing reduced ignition energy and voltage of LTNR. The mechanism was studied by the measurements of the coefficient of thermal conductivity, tests of EPR and TG-DSC-MS-FTIR. The results turn out that doping of Pb3O4 improve the coefficient of thermal conductivity and the decomposition vivacity of LTNR, increase the decomposition heat of LTNR and catalyzes decomposition of the nitro.LA was used to reveal the electron effect to the decomposition of no-heat sensitive primary explosives in the SCB plasma. The current signals in different explosive particles as an important source were chosen to understand the mechanism of SCB plasma electron in the decomposition of LA. The conclusion is that the SCB plasma electron directly involved in the reaction of metal ion, can make the transformation of Pb2+/Pb0 easier and thus can catalyzes decomposition of the LA.