title: A scanning drift tube apparatus for spatiotemporal mapping of electron swarms.
abstract: A "scanning" drift tube apparatus, capable of mapping of the spatiotemporal evolution of electron swarms, developing between two plane electrodes under the effect of a homogeneous electric field, is presented. The electron swarms are initiated by photoelectron pulses and the temporal distributions of the electron flux are recorded while the electrode gap length (at a fixed electric field strength) is varied. Operation of the system is tested and verified with argon gas; the measured data are used for the evaluation of the electron bulk drift velocity. The experimental results for the space-time maps of the electron swarms - presented here for the first time - also allow clear observation of deviations from hydrodynamic transport. The swarm maps are also reproduced by particle simulations.
authors.affiliation: Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest, Hungary.
authors.forename: I
authors.initials: I
authors.lastname: Korolov
authors.affiliation: Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest, Hungary.
authors.forename: M
authors.initials: M
authors.lastname: Vass
authors.affiliation: Institute of Experimental and Theoretical Physics, al-Farabi Kazakh National University, 96a Tole Bi, Almaty 050012, Kazakhstan.
authors.forename: N Kh
authors.initials: NKh
authors.lastname: Bastykova
authors.affiliation: Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Donkó