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{ |
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Plank's formula for black body radiation spectrum |
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} |
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{ Required constants } |
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k : 8.617e-5; { Boltzmann constant (eV/K) } |
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h : 4.136e-15; { Plank constant (eV-sec) } |
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e : 1.602e-19; { elemetary charge (Coulombs) } |
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c : 2.998e8; { speed of light (m/sec) } |
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{ |
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The following distribution is in units of Joules/meter^4, |
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i.e., energy per radiating volume per wavelength |
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lmb (lambda) is expected in nm (10^-9 meter) |
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and T must be given in degrees Kelvin |
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} |
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u(lmd,T) : 8*PI*h*e*c*(lmd*1e-9)^-5 / (exp(h*c/(lmd*1e-9*k*T)) - 1); |