Inverse Braking Radiation and Resonance Absorption in Corona Plasmas of Inertial Confinement Fusion

In this paper, combining the Maxwell equations with the electron balance equation, we obtain the inverse braking radiation absorption coefficient in a laser fusion corona plasma. For a fixed plasma temperature, variations of the absorption coefficient versus the penetration depth into the plasma are illustrated numerically for different values of laser wavelength. It is shown that, by increasing the skin depth of the laser into the plasma, the absorption coefficient increases and tends to asymptotic value one. The effect of plasma temperature on the absorption coefficient has also been investigated. In addition, the fraction of absorbed energy for resonance absorption is studied analytically and illustrated numerically. Moreover, the fractional absorption for different laser wavelengths as well as different values of incident angle is illustrated. It can be seen that, the maximum value of the absorption coefficient is independent of the laser wavelength and is about 0.6 for all the wavelengths.