Theoretical Solar Radio Flux Recombination Spectrum
Theoretical flux densities due to recombination (thick solid curve, displaced upwards by 8 orders of magnitude) and cascading (thin solid curve) within (half) a spherical shell (R=7*105km, ΔR=105 km) of a plasma of density Np=5*108cm-3, an average electron energy of 0.5 Ry and an ion temperature of T=106oK at a distance from the earth D=1.5*108 km (i.e. corresponding to the lower solar corona) for frequencies from 107 to 1010 Hz. The dashed curve (which is shown here displaced upwards by 8 orders of magnitude) gives the cascade emission if no radiative enhancement due to level broadening by plasma field fluctuations is assumed.
The result shows good agreement with experimentally obtained solar flux values for frequencies around 200 Mhz (see FIG.13b).