Atomic kinetics of matter irradiated by intense laser fields

The atomic kinetics of solid density low-Z material under an intense oscillating laser field is presented. The transient behavior of the average ionization and the heating mechanism is analyzed. Temporal oscillations in excited configurations populations caused by the laser field oscillations are demonstrated. These phenomena present a method for creating short, 1–100 fs, monochromatic but incoherent x-ray pulses and for measuring basic atomic rates.

Figure 1

Time evolution of the electron temperature curve (bottom, blue), and average ionization in the target curve (top, red).

Figure 2

Time-dependent skin depth top curve (red) and absorption coefficient bottom curve (blue).

Figure 3

Time evolution of the fractional populations of four most populated configurations.

Figure 4

Configurations diagram for the main atomic processes in the target under the laser field.

Figure 5

Radiation emitted at photon energy of 305 eV. the emission is presented for four treatments of the laser induced ionization rate: detailed time-dependent laser ionization oscillating curve (blue); laser ionization averaged for the laser cycle [24] curve (middle, black); laser ionization where the laser field taken to be constant during the pulse $E\left(t\right)=E_0$ bottom curve (green); no laser induced ionization, laser effect is taken only as a heating source curve (top, red).

Figure 6

Radiation emitted at photon energy of 305 eV. For laser intensities of ${10}^{16}{\mathrm{W}/\mathrm{cm}}^2$ top curve (blue) and ${10}^{17}{\mathrm{W}/\mathrm{cm}}^2$ bottom curve (red). The insert is a zoom in on the rectangle area.

Figure 7

Radiation emitted at photon energy of 256 eV.