Quasi-adiabatic compression of a plasma column by a longitudinal magnetic field

Approximate 1.5-dimensional MHD equations are derived that describe the quasi-adiabatic compression of a thin plasma column by a longitudinal magnetic field. The parameters of the compressed plasma are obtained analytically as functions of the initial conditions and longitudinal field. The stability of plasma compression against the Rayleigh-Taylor instability is investigated. It is shown that, in the Z-Θ-pinch geometry, increasing the longitudinal magnetic field makes it possible to achieve radial compression ratios of 20–30 without violating the cylindrical symmetry of the column. The possibility of thermonuclear ignition in a thin plasma column in a Z-Θ-pinch configuration is studied. The ranges of the initial plasma densities and temperatures and the initial lengths of the plasma column that are needed to achieve ignition in a plasma compressed by a factor of 20–30 are determined. The parameters of the electromagnetic energy source required to achieve such a high plasma compression are estimated.