Photon
Photon
Agenda today 1.Photon:the particle nature of radiation 2.Blackbody radiation 3.photoelectric effect 4.Compton effect
Agenda today 1. Photon: the particle nature of radiation 2. Blackbody radiation 3. photoelectric effect 4. Compton effect
Blackbody radiation(黑体辐射) Blackbody is a body that would absorb all the radiation falling on it Radiation intensity of blackbody (单色辐出度) Energy of electromagnetic waves of wavelength from 入to入+d入by unit surface e(2,T)= dE of blackbody in unit time dλ interval
Blackbody radiation(黑体辐射） Blackbody is a body that would absorb all the radiation falling on it Radiation intensity of blackbody （单色辐出度） Energy of electromagnetic waves of wavelength from to +d by unit surface of blackbody in unit time interval
A good emitter is also a good absorber
A good emitter is also a good absorber
e亿 The rate of radiation 1700K (总辐出度) 1500K The energy emitted by unit area of surface per unit 1300K time 1100K E(T)=()da 0123 4 (同 Stefan-Boltzmann equation E(T)=OT4 Stefan constant:o =5.6703x10 (W.m 2.K4)
0 1 2 3 4 The rate of radiation （总辐出度） The energy emitted by unit area of surface per unit time. Stefan-Boltzmann equation 4 Eo (T) o T Stefan constant:
Wien'sLaw(维恩位 九m·T=b 移定律) b=2.898×103(mK We can measure the surface temperature of stars by its Size of Star LI peak of Size of Earth's Orbit Size of Jupiters Or radiation Atmosphere of Betelgeuse HST·FOC curve PRC6-04·sT5clOP0·Januery15,1995·A,Dupr99Ct),MAsA
Wien’s Law（维恩位 移定律） We can measure the surface temperature of stars by its peak of radiation curve
The ultraviolet catastrophe(紫外灾难) e(2,T)=G24.T &Gn Rayleigh-Jeans theory 0123456789 (同
The ultraviolet catastrophe （紫外灾难） 0 1 2 3 4 5 6 7 8 9 Rayleigh-Jeans theory eo T c T 4 1 (, )
Planck's explanation Quantization of energy:photon(光子) ε=hf 12-662④64万s e(2,T)= 2πhc22 e2k7-1
Planck’s explanation 1 2 ( , ) 2 5 kT o h c e hc e T Quantization of energy: photon（光子） hf
Momentum of photon The rest mass of photon is zero By theory of relativity E8+ E hf h P= cc
Momentum of photon The rest mass of photon is zero By theory of relativity
Photoelectric effect(光电效应) AH G
Photoelectric effect（光电效应） G V K - A