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A novel unipolar charger for ultrafine aerosol particles with minimal particle losses

Wiedensohler, A. ; Büscher, P. ; Hansson, H. C. ; Martinsson, B. G. LU ; Stratmann, F. ; Ferron, G. and Busch, B. (1994) In Journal of Aerosol Science 25(4). p.639-649
Abstract

A unipolar diffusion charger with minimal particle losses in the ultrafine size range has been developed. This charger uses two radioactive α-sources to produce ions which are drawn into the charging region by an alternating electric field. The aerosol flow in the centre of the charging region is surrounded by a particle-free sheath air flow to prevent particle losses. Charged aerosol particles move in a "zigzag" manner in the charging channel under the influence of the alternating electric field. Positive gas ions, with higher electrical mobilities than ultrafine aerosol particles, homogeneously fill the entire charging region. Here, the aerosol becomes unipolarly charged. The charging efficiency is strongly dependent on the residence... (More)

A unipolar diffusion charger with minimal particle losses in the ultrafine size range has been developed. This charger uses two radioactive α-sources to produce ions which are drawn into the charging region by an alternating electric field. The aerosol flow in the centre of the charging region is surrounded by a particle-free sheath air flow to prevent particle losses. Charged aerosol particles move in a "zigzag" manner in the charging channel under the influence of the alternating electric field. Positive gas ions, with higher electrical mobilities than ultrafine aerosol particles, homogeneously fill the entire charging region. Here, the aerosol becomes unipolarly charged. The charging efficiency is strongly dependent on the residence time of the particles in the ion cloud. The ion current was measured in the charging region to determine the ion concentration. The residence time of the particles in the ion cloud was calculated for each stream line of the aerosol flow. The losses of ultrafine particles in the charger were experimentally determined. The unipolar charge distribution was measured and calculated by integrating the theoretical charge distribution over all stream lines of the aerosol flow.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Aerosol Science
volume
25
issue
4
pages
11 pages
publisher
Elsevier
external identifiers
  • scopus:0028445045
ISSN
0021-8502
DOI
10.1016/0021-8502(94)90005-1
language
English
LU publication?
yes
id
4b1fd30b-3062-4d94-9530-eaede09e0e92
date added to LUP
2019-05-16 09:20:07
date last changed
2020-01-13 01:47:43
@article{4b1fd30b-3062-4d94-9530-eaede09e0e92,
  abstract     = {<p>A unipolar diffusion charger with minimal particle losses in the ultrafine size range has been developed. This charger uses two radioactive α-sources to produce ions which are drawn into the charging region by an alternating electric field. The aerosol flow in the centre of the charging region is surrounded by a particle-free sheath air flow to prevent particle losses. Charged aerosol particles move in a "zigzag" manner in the charging channel under the influence of the alternating electric field. Positive gas ions, with higher electrical mobilities than ultrafine aerosol particles, homogeneously fill the entire charging region. Here, the aerosol becomes unipolarly charged. The charging efficiency is strongly dependent on the residence time of the particles in the ion cloud. The ion current was measured in the charging region to determine the ion concentration. The residence time of the particles in the ion cloud was calculated for each stream line of the aerosol flow. The losses of ultrafine particles in the charger were experimentally determined. The unipolar charge distribution was measured and calculated by integrating the theoretical charge distribution over all stream lines of the aerosol flow.</p>},
  author       = {Wiedensohler, A. and Büscher, P. and Hansson, H. C. and Martinsson, B. G. and Stratmann, F. and Ferron, G. and Busch, B.},
  issn         = {0021-8502},
  language     = {eng},
  number       = {4},
  pages        = {639--649},
  publisher    = {Elsevier},
  series       = {Journal of Aerosol Science},
  title        = {A novel unipolar charger for ultrafine aerosol particles with minimal particle losses},
  url          = {http://dx.doi.org/10.1016/0021-8502(94)90005-1},
  doi          = {10.1016/0021-8502(94)90005-1},
  volume       = {25},
  year         = {1994},
}