Theory of the Fireball

The W beyond 3.5 ev will be strongly absorbed at 4 0'. Thus the layers
of air at intermediate temperatures get additional heat which counteracts
and may even exceed the adiabatic cooling. This will tend to increase
the thickness of the medium-temperature layer. This in turn will (mod-
erately) lower the radiating temperature, but three-dimensional effects
act the opposite way (Sec. 6) .
a . Theory of Zel 'dovich et al.
Zelsdovich, Kompaneets, and Raizer lo (quoted as Z) have considered
the loss of radiation by hot material when the absorption coefficient
for the radiation increases monotonically with temperature. They have
shown that in this case a cooling wave proceeds into the hot material
from the outside. Tnis is to say, the cool temperature outside gradually
eats its way into the hot material, while the material in the center
remains unaffected and merely expands adiabatically.
For simplicity, ZelPdovich et al. consider a one-dimensional case.
They further as,sume that the specific heat is constant and express their
theory in terms of the temperature. This is not necessary; we shall
merely assume that both the enthalpy H and the absorption coefficient
for radiation are arbitrary but monotonically increasing functions of the
temperature. Like 2, we shall assume, in this subsection only, that the
radiation transport can be described by an opacity (Rosseland mean) rather
than considering each wave length separately.
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