Arrangement of the electrodes in the HV nanopulse experiment. The HV electrode is mounted coaxially with the confinement ring in order to provide a common axial symmetry of the confinement.
Temporal evolution of the voltage on the rf electrode after a single HV nanosecond pulse. Discharge parameters: , . designates the moment of the pulse launch.
Dependence of instability growth rate on the pulse repetition rate and amplitude for the cluster of 14 particles at , . The inset shows the evolution of the horizontal kinetic energy of the dust particles for the conditions of maximal at . For the unstable cluster of two microparticles similar evolution of energy and behavior of is observed.
Spectra of horizontal (solid line) and vertical (squares) oscillations of the microparticle for 2 (a) and 14 (b) particle clusters. For horizontal oscillations the spectrum is obtained as a power spectrum of the total horizontal kinetic energy . Note that kinetic energy is proportional to velocity squared and therefore is peaked at a double frequency of the cluster mode. is therefore determined as the frequency, corresponding to the highest peak, divided by 2. For vertical oscillations a resonance curve is measured by varying the pulse repetition rate . is the amplitude of the microparticle oscillations. For two particles , , and , driven at the frequency . For 14 particles , , and , driven at the frequency .
Evolution of the surface potential of a microparticle according to the Eqs. (1)–(3) at different secondary emission yields . At the potential increases about 15% in absolute value. The relaxation time of the surface potential may be estimated as .
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