Stability of a z-pinch with rising current
- Berkeley Research Associates, Springfield, VA (USA)
- Plasma Physics Division, Naval Research Laboratory, Washington, DC (USA)
A two-dimensional resistive MHD code is used to examine the stability of a z-pinch to {ital m}=0 perturbations under conditions of rising current. The current waveform is chosen to rise according to the one-third power of time in order to keep the unperturbed radius of the pinch constant. One-dimensional calculations show that regardless of the initial shape of the current density profile, the plasma column recovers the self-similar profile dictated by this current rise. In two-dimensions, initial perturbations corresponding to {ital m}=0 instability modes oscillate without growing or grow weakly at low values of the current in apparent contradiction to ideal MHD theory. At high current, the pinch is unstable with a growth rate predicted by ideal MHD. This is put forward as a possible explanation of experimental results which shown anomalously stable Z-pinches. Enhanced stability is also seen for low values of the Lundquist number when the current is set to the Pease-Braginskii value where the ohmic heating and radiative losses match.
- OSTI ID:
- 6357768
- Report Number(s):
- CONF-8904107--
- Journal Information:
- AIP Conference Proceedings (American Institute of Physics); (USA), Journal Name: AIP Conference Proceedings (American Institute of Physics); (USA) Vol. 195:1; ISSN 0094-243X; ISSN APCPC
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
COMPUTERIZED SIMULATION
CURRENTS
DATA
ELECTRIC CURRENTS
EQUILIBRIUM
INFORMATION
LINEAR PINCH DEVICES
LINEAR Z PINCH DEVICES
MHD EQUILIBRIUM
NUMERICAL DATA
OPEN PLASMA DEVICES
OSCILLATION MODES
PINCH DEVICES
PINCH EFFECT
PLASMA SIMULATION
SIMULATION
STABILITY
THEORETICAL DATA
THERMONUCLEAR DEVICES
TWO-DIMENSIONAL CALCULATIONS