Blackbody radiation refers to the spectrum of light emitted by any heated object; common examples include the heating element of a toaster and the filament of a light bulb.

The name “black body” is given because it absorbs all colors of light. It is an ideal emitter: at every frequency, it emits as much or more thermal radiative energy as any other body at the same temperature.

A black body can also be in thermal equilibrium in which it emits the electromagnetic black body radiation which is based on Planck’s law. Ideal emitter: The amount of thermal radiative energy emitted by the body is more than any other body at the same temperature and at any frequency.

T is given in K.

1. Spectral blackbody emissive power: the amount of radiation energy emitted by a black-
2. Eb,λ =
3. C1.
4. λ5[exp(C2/λT) − 1]
5. [W/(m2 · μm)]
6. C0.
7. = 2.998 × 108 [m/s] (vacuum conditions)
8. C1.

The total (including all wavelengths) radiant intensity and hemispherical total emissive power of a blackbody into a medium with constant index of refraction n are given by the Stefan-Boltzmann law, πIb = Eb = n 2σT 4.

(Eg​)=(1/T4)

(Eg)=T2.

2.1. The radiation intensity is a far field parameter which can be obtained by simply multiplying the radiation power density by the square distance, i.e., (2.99) (2.100) P r a d = ∮ Ω U d Ω = ∫ 0 2 π ∫ 0 π U sin ⁡

The intensity of radiation is defined as the rate of emitted energy from unit surface area through unit solid angle. The radiation from a surface has different intensities in different directions. The intensity of radiation along a normal to the surface is known as intensity of normal radiation, In.

electromagnetic radiation, such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation (γ) particle radiation, such as alpha radiation (α), beta radiation (β), proton radiation and neutron radiation (particles of non-zero rest energy)