Title :
Theory and design of the flow-through z-pinch experiment: ZaP
Author :
Shumlak, U. ; Nelson, B.A. ; Golingo, R.P. ; Tang, D. ; Crawford, E. ; Hartog, D.J.D. ; Holly, D.J.
Author_Institution :
Aerosp. & Energetics Res. Program, Washington Univ., Seattle, WA, USA
Abstract :
Summary form only given. The stabilizing effect of an axial flow on the m=1 kink instability in z-pinches has been studied numerically by reducing the linearized ideal MHD equations to a one-dimensional eigenvalue equation for the radial displacement. A diffuse z-pinch equilibrium is chosen that is made marginally stable to the m=0 sausage mode by tailoring the pressure profile. The principal result reveals that a sheared axial flow does stabilize the kink mode when the shear exceeds a threshold value which can be satisfied with a peak flow which is less than the Alfven speed for certain wavelengths. Additionally, the m=0 sausage mode is driven from marginal stability into the stable regime which suggests that the equilibrium pressure profile control can be relaxed. The flow stabilization agrees with experimental observations. The details of the theoretical development will be presented. The implications of this stabilizing effect are to be investigated with a flow-through Z-pinch experiment, ZaP. The experiment will produce a Z-pinch plasma which is 50 cm in length by initiating the plasma with a one meter Marshall gun. The design of the experiment will be presented in this paper.
Keywords :
Z pinch; eigenvalues and eigenfunctions; kink instability; plasma flow; Alfven speed; ZaP; axial flow; diffuse z-pinch equilibrium; equilibrium pressure profile control; flow stabilization; flow-through z-pinch experiment; kink mode; linearized ideal MHD equations; m=0 sausage mode; m=1 kink instability; marginal stability; one meter Marshall gun; one-dimensional eigenvalue equation; peak flow; plasma initiation; pressure profile tailoring; radial displacement; shear threshold value; sheared axial flow; stabilizing effect; stable regime; Coaxial components; Eigenvalues and eigenfunctions; Electrons; Equations; Magnetic flux; Magnetohydrodynamics; Plasma measurements; Plasma stability; Spectroscopy; Tokamaks;
Conference_Titel :
Plasma Science, 1998. 25th Anniversary. IEEE Conference Record - Abstracts. 1998 IEEE International on
Conference_Location :
Raleigh, NC, USA
Print_ISBN :
0-7803-4792-7
DOI :
10.1109/PLASMA.1998.677903