title: Comparison of impact ionisation plasma with laser ionisation creator: Mocker, Anna subject: ddc-530 subject: 530 Physics description: Impact ionisation is the basis for the method yielding the highest sensitivity for detection of dust particles in space. To cover a sufficiently big energy range for the investigation of dust particle impacts and the calibration of impact ionisation instruments, we attempted to supply the dust accelerator at the MPI for Nuclear Physics with laser ionisation. Therefore it is nec- essary to investigate the properties of both processes with respect to their comparability. For this, the characteristics of the emerging plasma, such as the velocity distribution of the ions, and the ion appearance in the TOF mass spectra are analysed and compared. The findings of this study show that, in general, laser ionisation plasma is not comparable to that generated by hypervelocity particle impacts. However, particular aspects of the the laser ionisation process can be used as a rough substitute for particle impacts, i.e. optimising and testing electronic components for impact ionisation instruments. Furthermore, the dependence of the plasma properties on the impact parameters were studied. Here, the experimental results imply that the defining parameter of the impact process is either the impact velocity or the energy density. date: 2010 type: Dissertation type: info:eu-repo/semantics/doctoralThesis type: NonPeerReviewed format: application/pdf identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/11631/1/Disstertation_AnnaMocker.pdf identifier: DOI:10.11588/heidok.00011631 identifier: urn:nbn:de:bsz:16-opus-116314 identifier: Mocker, Anna (2010) Comparison of impact ionisation plasma with laser ionisation. [Dissertation] relation: https://archiv.ub.uni-heidelberg.de/volltextserver/11631/ rights: info:eu-repo/semantics/openAccess rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html language: eng