AbstractDust grains are common in the space environment and being immersed in plasma, they become charged. It is well known that a motion of grains in space is driven mainly by electrodynamic forces and thus the grain charge is important for processes like the coagulation or dust cloud formations. Among other charging currents, emission processes are very important for setting the dust charge. It is believed that emission processes are connected exclusively with surface properties of dust grains but it is not evident for the surfaces covered by a very thin layer of different material (e.g., oxidized metal). For this reason, we investigate surface effects experimentally.Our experiment is based on an 3D electrodynamic trap. We caught a single dust grain for several days inside the vacuum vessel and exposed it to the electron/ion beam and studied charging/discharging processes. We have chosen spherically shaped melamine formaldehyde resin grains of a diameter 2.35 μm either with a clean surface or covered with a thin nickel film. An advantage of these samples is that the properties of bulk and surface materials are completely different. The effect of a surface modification was studied for ion and electron field emissions. We determined field intensities needed for significant emission currents as well as effective work functions for charged dust grains of particular material.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Impact of surface properties on the dust grain charging


    Beteiligte:
    Pavlů, J. (Autor:in) / Richterová, I. (Autor:in) / Šafránková, J. (Autor:in) / Němeček, Z. (Autor:in)

    Erschienen in:

    Advances in Space Research ; 38 , 11 ; 2558-2563


    Erscheinungsdatum :

    2005-02-02


    Format / Umfang :

    6 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch






    A model of coagulation in dust clouds during grain charging

    Barge, L. / Matthews, L. / Hyde, T. W. et al. | British Library Conference Proceedings | 2004


    A model of coagulation in dust clouds during grain charging

    Barge, L. / Matthews, L. / Hyde, T.W. | Elsevier | 2003


    Dust Grain Trajectory Determination Systems and Laboratory Studies of Photo-Electron Charging of Dust Grains

    Alexander, W. M. / Tanner, W. G. / Schaub, G. E. et al. | British Library Conference Proceedings | 1992