Development of sausage-type instability in a Z-pinch plasma column

Abstract

The development of sausage-type instabilities in an initially homogeneous Z-pinch plasma column has been investigated by means of numerical modelling. It is shown that in the presence of short-wave perturbations of a Z-pinch boundary and a rarefied plasma surrounding the pinch, cavities filled with a rarefied plasma and with a magnetic field are formed in the plasma column. As a result of this cavity growth, small columns of dense plasma form on the axis in the Z-pinch which have a temperature substantially higher than the average plasma temperature in the plasma column. When deuterium is present in the pinch, these dense high temperature bunches can become a source of intensive neutron radiation

Some features of the directional pattern of ion emission from a micropinch discharge

“…In the course of evolution of the current channel constriction, a cavern is formed [10]; therefore, the spreading of the micropinch plasma is close to spheri cally symmetric spreading. If the ion density in the hot spot is n ≈ 10 27 m -3 [3], the ion density is ~10 24 m -3 when the bunch of the spreading plasma has a size of 10 -4 m, which gives the mean free path of ions λ > 10 -4 m for the scattering cross sections σ < 20 -20 m 2 of ion-ion collisions [11].…”

Study of micro-pinches in wire-array Z pinches

“…[23][24][25][26][27] The formation of hot spots was interpreted as a result of the collapse of the Z-pinch necks due to the plasma outflow and radiative losses of energy in the micro-pinch. During the collapse, the diameter of the micro-pinch drops rapidly and the density of plasma increases significantly, but the expected temperature rise is not large.…”

Self-organization of high current-carrying plasmas: Toroidal plasmoid in neck of pinch discharge

“…Using [6,7], computer simulations of the above structure are carried out for the plasma tube with the inner conductor. Varying the plasma parameters, we reach the optimum conditions under which the plasmoid is developed.…”

“…On the basis of the ideal MHD theory [7], two-dimensional simulations of a neck development in the current-plasma column with the current of the direct and reverse directions at the axis and in the Mather's plasma focus device with the Π-like ridge at the anode have been performed. In the first case, the magnetic field maximum takes place in a valley, around which there is a vortex of the plasma drawn in from the outside.…”