Magnetic transport and radiation properties during compression of a magnetized plasma

We present a study of magnetic transport and radiation properties during compression of a magnetized laboratory plasma. A theta pinch is used to produce a magnetized plasma column undergoing radial implosion, with plasma parameters comprehensively measured through diverse diagnostic techniques. High-resolution observations show the implosion progressing through three stages: compression, expansion, and recompression. An anomalous demagnetization phenomenon is observed during the first compression stage, wherein the magnetic field at the plasma center is depleted as the density increases. We reveal the demagnetization mechanism and formulate a straightforward criterion for determining its occurrence, through analysis based on extended-magnetohydrodynamics theory and a generalized Ohm’s law. Additionally, we quantitatively evaluate the radiation losses and magnetic field variations during the two compression stages, providing experimental evidence that magnetic transport can influence the radiation properties by altering the plasma hydrodynamics. Furthermore, extrapolated results using our findings reveal direct relevance to magnetized inertial confinement fusion, space, and astrophysical plasma scenarios.