1000 Solved Problems in Modern Physics

(Tina Meador) #1

378 7 Nuclear Physics – I


Maximum shift in wavelength

(Δλ)max= 2 λc (7.38b)

Shift in frequency


ν=ν 0 /(1+α(1−cosθ)) (7.39a)
whereα=hν 0 /mc^2 (7.39b)
Δν=ν 0 −ν=αν 0 (1−cosθ)/(1+α(1−cosθ))

Energy of recoil electron


T=hν 0 −hν=αhν 0 (1−cosθ)/(1+α(1−cosθ)) (7.40)

Angular relation


cotφ=(1+α)tan(θ/2) (7.41)

Compton attenuation coefficients


I=I 0 exp(−μcx) (7.42)

Ifxis in cm thenμcis in cm−^1 ;ifxis in g/cm^2 which is obtained by multiplying
xcm byρ(the density), thenμis in cm^2 /g


Photoelectric effect


If the incident photon is absorbed by an electron in the atom or metal, and the
electron is ejected then the process is known as photoelectric effect. The kinetic
energy of the photoelectron


T=hν−W ( Einstein’s equation) (7.43)

whereWis the ionization energy of the ejected electron


eVo=

1

2

mνmax^2 =hν−W (7.43a)

Threshold energyhν 0 =W (7.44)
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