Experimental study of the underwater plasma based on the phased array vibrator system
In this paper, a set of underwater plasma vibroseis system was developed, which included three big systems, i.e. charge system, discharge system and trigger system. At the same time, an experimental platform was set up through tketornix digital oscilloscope, seismic detector and desktop computer for collecting and processing data. On this basis, three working stages (breakdown, detonation and spread) of the underwater plasma were carried out the experimental research and summary. By experiment, the electrical properties of the underwater plasma were investigated under the different electrode materials, different number of electrodes, different voltages, different electrode gap spacing conditions. By using the ORIGIN data analysis software, the plasma channel resistance and the trend of the change of discharge power in time domain were obtained. It laid a foundation for choosing the optimal transducer structure and its material. In addition, the process of pulsed discharge in water was analysed. By comparing and summarizing, it found that the efficiency of corona discharge significantly is higher than that of arc discharge. This research provides references for the design of the plasma source in water.
New prototype of underwater sound source based on the pulsed corona discharge
Abstract Two types of underwater pulsed discharge, spark discharge and corona discharge, have been studied in this paper. The pulsed corona discharge current under voltages ranging from 2 to 4 kV and conductivities of liquid ranging from 325 μS/cm to 20 mS/cm have been measured and the process of bubble's growth has been observed. Several results could be summarized from our experiments: (a) there is no conducting plasma channel in the underwater corona discharge; (b) effect of corona discharge does not depend on the distance of the gap between both electrodes; (c) discharge currents in corona discharge are highly dependent on conductivity which may prompt the fact that ionic current play a major role in the discharge process; (d) the underwater pulsed corona discharge can generate acoustical pulses when the conductivity is high enough. The corona acoustic intensity is similar to that of spark under the same conditions. A new model was put forward based on these experimental results.
Hamiltonian reduction of SU(2) gluodynamics
The Hamiltonian reduction of the Yang-Mills theory with the structure group SU(2) to a nonlocal model of a self-interacting 3 × 3 positive semidefinite matrix field is presented. Analysis of the field transformation properties under the action of the Poincare group is carried out. It is shown that, in the strong coupling limit, the classical dynamics of a reduced system can be described by the local theory of interacting nonrelativistic spin-0 and spin-2 fields. A perturbation theory in powers of the inverse coupling constant g−2/3 that allows calculating the corrections to a leading long-wave approximation is suggested.