Ou Haibin, Duan Shuchao, Wang Ganghua, et al. Two-dimensional simulation of dense plasma focus[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202436.240001
Citation:
Ou Haibin, Duan Shuchao, Wang Ganghua, et al. Two-dimensional simulation of dense plasma focus[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202436.240001
Ou Haibin, Duan Shuchao, Wang Ganghua, et al. Two-dimensional simulation of dense plasma focus[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202436.240001
Citation:
Ou Haibin, Duan Shuchao, Wang Ganghua, et al. Two-dimensional simulation of dense plasma focus[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202436.240001
In order to investigate the motion law of the plasma sheath in a dense plasma focus (DPF) device and the influence of related design parameters, this paper uses a self-developed FOI program to conduct two-dimensional magnetohydrodynamic simulation of the plasma sheath motion process and focus formation process in the Mather type discharge chamber structure, and obtains results similar to the visible light experimental images of the Livermore National Laboratory in the United States. At the same time, the influence of different pressure, current, anode radius and cathode-anode gap on the motion law of the plasma sheath is explored. The calculation results show that the plasma sheath will compress the gas radially with a certain degree of curvature, which is one of the reasons for the instability phenomenon; the axial velocity of plasma sheath is inversely proportional to the square root of pressure, and is proportional to the current. The larger the anode size of the device, the smaller the axial velocity of sheath. To increase the current, it is necessary to extend the anode length to match the focusing time with the current peak. The gap between cathode and anode has little effect on the axial motion process of plasma sheath near the anode.
Figure 1. schematic diagram of boundary conditions in computational domain
Figure 2. plasma sheath motion process in DPF
Figure 3. simulation of the axial motion of the plasma sheath at the top of the anode, compared with the motion of the plasma sheath captured by the Livermore National Laboratory in the United States[11]
Figure 4. effect of pressure on axial velocity of sheath
Figure 5. influence of different current amplitudes on axial velocity of sheath, pinch time and compression ratio
Figure 6. effect of anode radius on axial velocity of sheath
Figure 7. effect of anode radius on pinch time and compression ratio
Figure 8. time of plasma layer reaching the top of anode under different cathode-anode gaps
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