An external beam PIXE/PESA setup for characterization of fine aerosols

• An external beam setup has been developed for the determination of elemental concentrations in fine aerosols (aerodynamic particle diameter less than about 2 μm). Carbon, nitrogen and oxygen are determined with particle elastic scattering analysis (PESA) and, simultaneously, elements heavier than silicon with PIXE at a proton energy of 3.58 MeV. Earlier work on aerosols with PESA and most PIXE work have been performed with the aerosol sample in high vacuum, which causes losses of certain compounds, e.g. several organic substances present in atmospheric aerosols. These losses are increased by the heating effect of the beam. The rate of mass loss of different aliphatic hydrocarbons has been investigated for different chamber gas pressures, chamber gas exchange rates and beam current densities. The external beam approach showed a considerable improvement compared with high vacuum analysis. The external beam setup is described in some detail with respect to geometry, electronics and the chamber gas-handling system.

Ämnesord

NATURVETENSKAP  -- Fysik -- Acceleratorfysik och instrumentering (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Accelerator Physics and Instrumentation (hsv//eng)

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)