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

Abstract: In this paper, combining the Maxwell equations with the electron balanceequation, we obtain the inverse braking radiation absorption coefficient in a laser fusioncorona plasma. For a fixed plasma temperature, variations of the absorption coefficientversus the penetration depth into the plasma are illustrated numerically for differentvalues of laser wavelength. It is shown that, by increasing the skin depth of the laserinto the plasma, the absorption coefficient increases and tends to asymptotic value one.The effect of plasma temperature on the absorption coefficient has also beeninvestigated. In addition, the fraction of absorbed energy for resonance absorption isstudied analytically and illustrated numerically. Moreover, the fractional absorption fordifferent laser wavelengths as well as different values of incident angle is illustrated. Itcan be seen that, the maximum value of the absorption coefficient is independent of thelaser wavelength and is about 0.6 for all the wavelengths.