Research Fig.8a:
Density of atoms in excited states (thick solid curve, left ordinate) as a function of the principal quantum number n (lower abscissa)
for a plasma density Np=105cm-3. The thin solid curve gives the production rate q
n (left ordinate to be multiplied by 10
5) with the close dashed-dotted curve showing the initial recombinative production rate q
nRec (i.e. neglecting the cascading rate q
ncasc). The total loss frequency is given by the sum of the level decay constant A
n (long-dashed curve), the collisional ionization frequency (dashed curve) and the photoionization frequency (dotted curve) where the latter corresponds to an enhanced solar radio flux as appropriate
for a strong ('Type IV') solar burst (see
FIG.8b) (F
sol=1). (See
FIG.6 for normal solar flux conditions, The upper abscissa shows the frequency of the n-alpha transition for the quantum number n and gives an approximate idea which levels are responsible for scattering an electromagnetic wave of a certain frequency.
