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The effect of carrier gas contaminants on the charging probability of aerosols under bipolar charging conditions.

Steiner G, Reischl GP - J Aerosol Sci (2012)

Bottom Line: A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses.Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols.The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien, Austria ; Department of Physics, University of Helsinki, P.O. Box 64, 00014, Finland.

ABSTRACT
This work concentrates on the experimental determination of the properties of ionic molecular clusters that are produced in the bipolar ionic atmosphere of a radioactivity based (241)Am charger. The main scope of this study was to investigate the dependency of the ions' properties on carrier gas contaminants caused by the evaporation of trace gases from different kinds of frequently encountered tubing materials. A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses. It was found that impurities in the carrier gas dramatically change the pattern of the ion mobility/size distribution, resulting in very different ion properties that strongly depend on the carrier gas composition. Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols. The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

No MeSH data available.


Related in: MedlinePlus

Schematic cross section of the “Tapcon and Analysesysteme” aerosol charger. It is equipped with an 241Am source with an activity of approximately 60 MBq and has a total volume of about 32 cm³.
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f0005: Schematic cross section of the “Tapcon and Analysesysteme” aerosol charger. It is equipped with an 241Am source with an activity of approximately 60 MBq and has a total volume of about 32 cm³.

Mentions: In this work an aerosol charger (tapcon ID: “tapcon minicharger”) purchased from “Tapcon & Analysesysteme”, equipped with an 241Am source was used to investigate the properties of the generated ion clusters (Fig. 1). 241Am decays by alpha emission with an energy of 5.5 MeV and a small by-product of gamma rays to 237Np with a half live of about 2 million years. The most evident advantage of 241Am chargers, compared to other radioactive chargers equipped with 210Po or 85Kr, is its long half life of 432.2 years (210Po: 138.2 days, 85Kr: 10.8 years). Therefore, a decrease of ion production can be almost completely neglected within our comparably short human lifetime.


The effect of carrier gas contaminants on the charging probability of aerosols under bipolar charging conditions.

Steiner G, Reischl GP - J Aerosol Sci (2012)

Schematic cross section of the “Tapcon and Analysesysteme” aerosol charger. It is equipped with an 241Am source with an activity of approximately 60 MBq and has a total volume of about 32 cm³.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3473358&req=5

f0005: Schematic cross section of the “Tapcon and Analysesysteme” aerosol charger. It is equipped with an 241Am source with an activity of approximately 60 MBq and has a total volume of about 32 cm³.
Mentions: In this work an aerosol charger (tapcon ID: “tapcon minicharger”) purchased from “Tapcon & Analysesysteme”, equipped with an 241Am source was used to investigate the properties of the generated ion clusters (Fig. 1). 241Am decays by alpha emission with an energy of 5.5 MeV and a small by-product of gamma rays to 237Np with a half live of about 2 million years. The most evident advantage of 241Am chargers, compared to other radioactive chargers equipped with 210Po or 85Kr, is its long half life of 432.2 years (210Po: 138.2 days, 85Kr: 10.8 years). Therefore, a decrease of ion production can be almost completely neglected within our comparably short human lifetime.

Bottom Line: A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses.Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols.The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien, Austria ; Department of Physics, University of Helsinki, P.O. Box 64, 00014, Finland.

ABSTRACT
This work concentrates on the experimental determination of the properties of ionic molecular clusters that are produced in the bipolar ionic atmosphere of a radioactivity based (241)Am charger. The main scope of this study was to investigate the dependency of the ions' properties on carrier gas contaminants caused by the evaporation of trace gases from different kinds of frequently encountered tubing materials. A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses. It was found that impurities in the carrier gas dramatically change the pattern of the ion mobility/size distribution, resulting in very different ion properties that strongly depend on the carrier gas composition. Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols. The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

No MeSH data available.


Related in: MedlinePlus