After the explosion in a confined space aluminum aerosol particle size spectrum and its produce changes over time

Plutonium oxidation at different temperatures size particles varies with temperature . Generally produce plutonium wire explosion PM2.5 ( particle size less than 2.5μm) particles , the particle size for the safety assessment and environmental protection is important. Existing chemical nanoscale aluminum powder explosives and explosion in a confined space generated aerosol particle size spectrum and its changes over time for  2 way manifold  reports . Studies conducted in our laboratory showed that , despite the size spectrum with specific  Valve manifolds  vary, but nanoscale particle number concentrations are high. Agglomeration and sedimentation of collision and other reasons , the particle number concentration change with time approximately exponential decay law , " half-life " in the range of 30 ~ 90min . To avoid inhaling plutonium irradiation damage caused by  Stainless steel needle valve  plutonium experiments exhaust general subject of nuclear grade HEPA filter processing, in which plutonium concentrations below the national standard limit to emissions. Of radiation protection regulations , 239PuO2 derived air concentration 0.2Bq/m3. Currently, the widespread use of plutonium aerosol α continuous monitor for continuous online monitoring of plutonium aerosol , the principle is: membrane aerosol particles collected online , the emission of α particles with α detectors measure , according to the judgment particle energy spectrum nuclide composition and content .