A new experimental set-up for the characterization of aerosols has been developed, in order to support with experimental data a better understanding of the source term related to Radiological Dispersal Events (RDE's). We have developed this set-up with the aim of studying the separate eect of temperature, materials and dierent atmospheres on the characteristics of the produced aerosols, concentrating on the description of aerosol's size distribution and, their chemical and elemental composition. In the experiments we simulate RDE's by applying dierent thermal transients to the sample materials, employing a laser heating technique. Part of the sample is vaporized, and aerosols are generated by nucleation/condensation of the formed vapour in a controlled atmosphere.
The laser heating technique has been chosen as it permits high exibility in regulating the thermal transient and the possibility of reaching extreme conditions, such as high temperature (up to 4500 K) with rapid transients (tenths of ms). Dierent collection systems have been developed (using inertia impaction phenomena or lters) and permit the collection of the aerosols on dierent substrates and the application of dierent post-analysis techniques for aerosols characterization (SEM/EDX, RAMAN, ICP-MS). The set-up has been tested for dierent materials, such as ceramic, salts and metals, and proved to be feasible for the production, collection and post-analyses of aerosols. In this paper will describe our original set-up, focusing on the instrumentation applied, on the post analysis techniques and on the experimental procedure. Finally we willalso give examples of the results obtained.
JOURNAL OF AEROSOL SCIENCE p. 36-49 vol. 70