Study of Interaction of Plasma Flows with Magnetic Field During Implosion of Cone-Cylindrical Nested Arrays

The results of the studies of the compression of the plasma of cone-cylindrical nested arrays of mixed composition at current flow through them of up to 3 MA at the Angara-5-1 facility are presented. The outer array of the nested array is a conical array of thin nylon fibers or tungsten wires, while the inner one is a cylindrical tungsten wire array. The implosion of current in this type of nested arrays is a unique opportunity for simulating the interaction of magnetized plasma flows with a strong magnetic field. In the space between the inner and outer arrays, the super-Alfvén plasma flow from the outer array collides with the magnetic field of the discharge current through the inner array. As a result of this interaction in the space between arrays, different plasma flow modes are implemented: pre-Alfvén ( V r < V А ), super-Alfvén ( V r > V А ), and a mode with the formation of the transition region—a shock wave (SW) between arrays, depending on the ratio of the plasma formation rates of arrays of nested array and on the ratio of their radii. The SW region formation in the space between arrays occurs near the inner array, where the kinetic pressure of the plasma flow from the outer array is balanced by the magnetic pressure of the discharge current of the inner array. New experimental data was obtained on the features of the SW region formation near the surface of the inner array and the nature of its change during the interaction. The use of an external conical array enabled us to obtain the SW position depending on the ratio of radii of the outer and inner arrays in one shot. It is shown that the interaction of plasma flows of the outer conical array with the magnetic field of the inner cylindrical array leads to a significant decrease in the zipper-effect at the final stage of plasma compression of the inner array and the pinch formation. The obtained experimental results are compared with the results of simulating the plasma motion between the arrays using the three-dimensional radiation-magnetohydrodynamic code MARPLE3D.