Simulation of laser-driven x-ray backlighter
نویسندگان
چکیده
One of applications proposed for PHELIX is ignition of hot laser sparks for x-ray shadowgraphy and K-shell absorption spectroscopy of heavy-ion-beam targets [1]. In 2004 we started numerical simulation and optimization of laserdriven x-ray backlighter. An emphasis of this study is on efficiency of conversion of the laser pulse energy into hard x-rays. Here we present the computational tools and first results. The simulation is performed in two steps. First, the laserfoil interaction is simulated by MULTI-FS two-temperature Lagrangian 1D hydrodynamic model with multi-group radiation transport [2], improved. Next, for each Lagrangian cell, solution of hydrodynamic equations is post-processed by atomic kinetics code [3], which gives a distribution of ions over quantum states. Plasma density effects (continuum lowering, collectivization of bound states, etc.) are treated in the effective-statistical-weights approach [4]. In the atomic kinetics model, the cells interact due to radiation, which is determined as a multi-layer solution of the radiative transfer equation on a fine spectral grid. Spectral line shapes are affected by the Doppler broadening, cell-to-cell Doppler shifts caused by the plasma flow, and dynamic Stark effect. Besides the internal radiation field we simulate spectral intensity of radiation outgoing the spark in various directions. This allows to choose an optimal direction for installation of x-ray monochromator. Fi 10
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تاریخ انتشار 2005