Basic characteristics of kinetic energy transfer in the dynamic hohlraums of Z-pinch

Abstract

The applications of Z-pinch are realized through dynamic hohlraum driven by Z-pinch, in which a uniform and symmetrical radiation field may be produced for ablating implosion of the inertial confinement fusion (ICF) capsule, and the radiation sources may also be created for heating and backlighting the samples in opacity measurement experiments. The radiation field is essentially related to driven current, hohlraum configuration and material. In physics it is determined by energy transfer in the hohlraum. For rapidly obtaining the knowledge about the primary energy transfer chracteristics in the hohlraum, and its trends of variation in the configuration, linear mass of the load, and the driven current, the simplified model is used to simulate the dynamic hohlraum implosion. The obtained implosion kinetic energy of the cylindrical foam accords well with the kinetic energy obtained from a one-dimensional magneto radiation hydrodynamics simulation of Z-pinch-driven dynamic hohlraum. In the dynamic hohlraum for ICF the kinetic energy loss is important for the radiation field formation when the imploding wire-array plasma collides with the cylindrical foam, while ones for radiation source the kinetic energy loss and for the final implosion kinetic energy of the foam are both important. The maximum implosion kinetic energy of cylindrical foam is directly proportional to the square of the peak current, while the kinetic energy loss increases with the mass of cylindrical foam increasing. The mass energy density in the foam tends to increase, and in turn the radiation power is enhanced when the rise time of the current turns longer.