Computational investigation of the limits to Pease-Braginskii collapse of a Z-pinch

Technical Report · Mon Jun 01 04:00:00 EDT 1981

DOI:https://doi.org/10.2172/6441031· OSTI ID:6441031

Nielsen, P D

This dissertation investigates the one-dimensional limits to such a radiation enhanced collapse through the use of a Lagrangian simulation code, LASNEX. The code includes the effects of a wide range of phenomena - opacity, ionization, experimentally determined equations of state, magnetic effects on transport coefficients, and external electrical circuits. Special attention was given to the magnetic field subroutines. They were revised to include ion acoustic and lower hybrid drift induced resistivity and to increase accuracy and efficiency. The magnetic pressure term was differenced in a manner that eliminates any influence of zone size, allowing large, low density zones outside the plasma column. In these large zones, magnetic flux and energy were determined by direct integration instead of summation to increase overall conservation. With these changes, the computational timesteps were determined by phenomena in the plasma instead of the Alfven velocity in the low density region. These modifications improved the accuracy of the code on Z-pinch problems by a factor of 10-100 depending on the minimum pinch radius reached.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6441031
• Report Number(s): UCRL-53166; ON: DE81028787
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700105* -- Fusion Energy-- Plasma Research-- Plasma Kinetics-Theoretical-- (-1987)
COMPUTER CALCULATIONS
CURRENTS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
LINEAR PINCH DEVICES
LINEAR Z PINCH DEVICES
MAGNETIC FIELD CONFIGURATIONS
OPEN PLASMA DEVICES
PHYSICAL PROPERTIES
PINCH DEVICES
PINCH EFFECT
PLASMA PRESSURE
THERMONUCLEAR DEVICES