Theory of the Fireball
Theory of the Fireball
Theory of the Fireball
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esult <strong>of</strong> <strong>the</strong> three-dimensional considerations, <strong>the</strong> one-dimensional for-<br />
.<br />
mda (5 -35 yields a decrease <strong>of</strong> p/p as t -'.<br />
Using (5.33), a constant mass absorption coefficient requires<br />
-1/3n 4/20<br />
T; - P "P (6.28)<br />
Thus in three dimensions, <strong>the</strong> temperature continues to increase slowly<br />
after <strong>the</strong> cooling wave reaches <strong>the</strong> iso<strong>the</strong>rmal sphere. If we assume tinat<br />
times up to x = 2.5 in Table IX are significant, tne pressure decreases<br />
by about a factor <strong>of</strong> 3 in Stage C 11, and <strong>the</strong> temperature <strong>of</strong> <strong>the</strong> radiating<br />
d<br />
layer increases by about 513 according to (6.28). The radiated power,<br />
2 14<br />
being proportional to R1 T1 , may increase by about 10:'. up to x = 2,<br />
and <strong>the</strong>n decreases due to <strong>the</strong> shrinkage <strong>of</strong> <strong>the</strong> radiating surface.<br />
One prediction <strong>of</strong> this <strong>the</strong>ory is that <strong>the</strong> temperature,as well as<br />
<strong>the</strong> radiated power. has a ra<strong>the</strong>r flat second maximum while <strong>the</strong> iso<strong>the</strong>rmal<br />
sphere radiates<br />
treatment <strong>of</strong> J1<br />
I -<br />
away its energy. The slaw vwiation <strong>of</strong> T justifies <strong>the</strong><br />
1<br />
as constant in Sec. 6b .<br />
7. TRANSPARENT FIREBALL ( Stage D)<br />
After <strong>the</strong> iso<strong>the</strong>rmal sphere has been eliminated by <strong>the</strong> cooling wave,<br />
<strong>the</strong> fireball is transparent if we neglect <strong>the</strong> effect <strong>of</strong> toe bomb debris.<br />
At this time <strong>the</strong> pressure is given by (6.21), <strong>the</strong> average temperature <strong>of</strong><br />
<strong>the</strong> 'barn" region is about 70Oo0, and <strong>the</strong> corresponding density is about<br />
80