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Local concentration of two-dimensionally perturbed ion-acoustic pulses

The evolution of two-dimensionally perturbed ion-acoustic pulses is carefully studied by using a double plasma device. The two-dimensional perturbation is caused by the insertion of a floating planar obstacle. Results reveal that the local concentration or focusing of the ion-acoustic pulse possible occurs in the shadow region of the obstacle. Finally, a tentative interpretation of the observed phenomenon is also given.