Measurements of the power spectrum and dispersion relation of self-excited dust acoustic waves
Nosenko, V.; Zhdanov, S. K.; Kim, S.-H.; Heinrich, J.; Merlino, R. L.; Morfill, G. E.; Nosenko, V.; Max-Planck-Institut für extraterrestrische Physik - D-85741 Garching, Germany, EU; Zhdanov, S. K.; Max-Planck-Institut für extraterrestrische Physik - D-85741 Garching, Germany, EU; Kim, S.-H.; Department of Physics and Astronomy, The University of Iowa - Iowa City, IA 52242, USA; Heinrich, J.; Department of Physics and Astronomy, The University of Iowa - Iowa City, IA 52242, USA; Merlino, R. L.; Department of Physics and Astronomy, The University of Iowa - Iowa City, IA 52242, USA; Morfill, G. E.; Max-Planck-Institut für extraterrestrische Physik - D-85741 Garching, Germany, EU
Журнал:
EPL (Europhysics Letters)
Дата:
2009-12-01
Аннотация:
The spectrum of spontaneously excited dust acoustic waves was measured. The waves were observed with high temporal resolution using a fast video camera operating at 1000 frames per second. The experimental system was a suspension of micron-size kaolin particles in the anode region of a dc discharge in argon. Wave activity was found at frequencies as high as 450 Hz. At high wave numbers, the wave dispersion relation was acoustic-like (frequency proportional to wave number). At low wave numbers, the wave frequency did not tend to zero, but reached a cutoff frequency instead. The cutoff value declined with distance from the anode. We ascribe the observed cutoff to the particle confinement in this region.
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