| 1. |
- Mentes, B., et al.
(författare)
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Vaporisation characteristics and detection limits of ion beam thermography
- 1999
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 150:1-4, s. 136-143
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Tidskriftsartikel (refereegranskat)abstract
- Analytical properties of the chemical speciation method, Ion beam thermography (IBT), have been investigated. IBT combines the multi-elemental ion beam techniques PIXE, PESA, pNRA and cPESA with thermography. During thermography the sample temperature is gradually increased, causing vaporisation of chemical compounds at specific temperatures and the sample at the same time undergoes analysis by the above-mentioned techniques. The characteristic vaporisation temperature (CVT) and the stoichiometric relations between the elements vaporised at that temperature, identify the chemical compounds. This work describes the reproducibility of the method, the dependence of the rate of temperature increase, the dependence of the sample thickness and the influence from aerosol particle size on the CVT. In addition the minimum detectable mass changes for IBT analysis of marine and continental aerosols were estimated by calculation for major and minor elements.
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| 2. |
- Papaspiropoulos, G., et al.
(författare)
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High sensitivity elemental analysis methodology for upper tropospheric aerosol
- 1999
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 150:1-4, s. 356-362
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a sampling and analysis tool for aerosol particles has been developed. Its purpose is to characterize upper tropospheric aerosols, where concentrations are low. Since measurements will be made from an airplane, a time resolution of one hour is desirable. These conditions require efficient sampling and analysis with low detection limits. To accomplish this, our sampler uses impaction, concentrating the aerosol deposit on a small area. The impactor has 14 parallel sampling lines which are used sequentially to achieve the time resolution. The elemental analysis is done with Particle-Induced X-ray Emission (PIXE), profiting from its high absolute sensitivity. The aerosol is expected to contains primarily sulphur (S) and emphasis is placed on this element, however the multi-elemental nature of PIXE is of course used. Several substrates have been investigated regarding minimum detection limits. Scanning Transmission Ion Macroscopy (STIM) analysis has been conducted on two outdoor aerosol samples, rendering three-dimensional images and mass distribution profiles. The setup was tested at ground level with high time resolution (5 min). Results show that the detection capabilities are excellent.
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