Impact of the laser magnetic field on recombination and bremsstrahlung radiation from atomic ionization rescattering in ultraintense fields

Recombination and bremsstrahlung radiation yields from strong field rescattering of $9\times {10}^{14}\mathrm{W}∕{\mathrm{cm}}^2\left({\mathrm{Ne}}^{+}\right)\text{to}3\times {10}^{17}\mathrm{W}∕{\mathrm{cm}}^2\left({\mathrm{Ne}}^{8+}\right)$ photoelectrons show the laser magnetic field alters the rescattering dynamics for fields beyond one-atomic unit of field $(3\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2)$. At $3\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$, the deflection of the rescattering wave begins to exceed its transverse width and the yields of photons with energies above $100\text{hartree}$ of energy $\left(2.7\mathrm{keV}\right)$ are attenuated. Radiation at $3\times {10}^{17}\mathrm{W}∕{\mathrm{cm}}^2\left({\mathrm{Ne}}^{8+}\right)$ is suppressed by ${10}^2$ for the highest energy photons near $1000\text{hartree}$ and by ${10}^5$ for lower energy in the range of $10–100\text{hartree}$.

Figure 1

(Color online) Photoelectron wave packet time evolution after ionization near the peak of the laser field (a) to rescattering at $9\times {10}^{14}\mathrm{W}∕{\mathrm{cm}}^2$ from Ne (b), $9\times {10}^{15}\mathrm{W}∕{\mathrm{cm}}^2$ from ${\mathrm{Ne}}^{3+}$ (c), and $3\times {10}^{17}\mathrm{W}∕{\mathrm{cm}}^2$ from ${\mathrm{Ne}}^{7+}$ (d). The linear 10-shade scale represents 0 to maximum flux for (b), 0 to $\frac{3}{4}$ maximum in (c), and 0 to half-maximum flux for (d). Above maximum, one color (red) is assigned to the flux for (c,d).

Figure 2

(Color online) Rescattering fluence $F_r$ without ${\mathbf{B}}_{\text{laser}}$ (blue) and with ${\mathbf{B}}_{\text{laser}}$ (black) for ionization from ${\mathrm{Ne}}^{+}$ to ${\mathrm{Ne}}^{8+}$ at saturation. A connecting line is shown to guide the eye.

Figure 3

(Color online) Energy spectrum of rescattering fluence at $9\times {10}^{14}\mathrm{W}∕{\mathrm{cm}}^2$ with a ${\mathrm{Ne}}^{+}$ parent ion (dark blue), $3\times {10}^{15}\mathrm{W}∕{\mathrm{cm}}^2$ (blue), $9\times {10}^{15}\mathrm{W}∕{\mathrm{cm}}^2$ (light blue), $2\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$ (yellow), $5\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$ (light brown), $8\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$ (brown), $2\times {10}^{17}\mathrm{W}∕{\mathrm{cm}}^2$ (gray), and $3\times {10}^{17}\mathrm{W}∕{\mathrm{cm}}^2$ with a ${\mathrm{Ne}}^{8+}$ parent ion (black). The results are shown with ${\mathbf{E}}_{\text{laser}}$ (a) and with both ${\mathbf{E}}_{\text{laser}}$ and ${\mathbf{B}}_{\text{laser}}$ (b).

Figure 4

(Color online) Energy-resolved yield of the total radiation from rescattering recombination (a) and bremsstrahlung (b) at $9\times {10}^{14}\mathrm{W}∕{\mathrm{cm}}^2$ with a ${\mathrm{Ne}}^{+}$ parent ion (dark blue), $3\times {10}^{15}\mathrm{W}∕{\mathrm{cm}}^2$ (blue), $9\times {10}^{15}\mathrm{W}∕{\mathrm{cm}}^2$ (light blue), $2\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$ (yellow), $5\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$ (light brown), $8\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$ (brown), $2\times {10}^{17}\mathrm{W}∕{\mathrm{cm}}^2$ (gray), and $3\times {10}^{17}\mathrm{W}∕{\mathrm{cm}}^2$ with a ${\mathrm{Ne}}^{8+}$ parent ion (black).

Figure 5

(Color online) Plot of radiation from rescattering at $9\times {10}^{14}\mathrm{W}∕{\mathrm{cm}}^2$ with a ${\mathrm{Ne}}^{+}$ parent ion (dark blue), $3\times {10}^{15}\mathrm{W}∕{\mathrm{cm}}^2$ (blue), $9\times {10}^{15}\mathrm{W}∕{\mathrm{cm}}^2$ (light blue), $2\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$ (yellow), $5\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$ (light brown), $8\times {10}^{16}\mathrm{W}∕{\mathrm{cm}}^2$ (brown), $2\times {10}^{17}\mathrm{W}∕{\mathrm{cm}}^2$ (gray), and $3\times {10}^{17}\mathrm{W}∕{\mathrm{cm}}^2$ with a ${\mathrm{Ne}}^{8+}$ parent ion (black).

Figure 6

(Color online) Energy-resolved yield of the bremsstrahlung radiation in ${\mathrm{Ne}}^{+}$ (dark blue), ${\mathrm{Ne}}^{4+}$ (yellow), and ${\mathrm{Ne}}^{8+}$ (black) at saturation with ${\mathbf{B}}_{\text{laser}}$. The results without screening (solid) and with screening (dashed) are shown.