378
7 Nuclear Physics – I
Maximum shift in wavelength
(Δ λ) max = 2 λ c
(7.38b)
Shift in frequency
ν = ν 0 /(1 + α(1 − cos θ))
(7.39a)
where α = h ν 0 /mc
2
(7.39b)
Δ ν = ν 0 − ν = α ν 0 (1 − cos θ)/(1 + α(1 − cos θ ))
Energy of recoil electron
T = h ν 0 − h ν = α h ν 0 (1 − cos θ)/(1 + α (1 − cos θ ))
(7.40)
Angular relation
cot ϕ = (1 + α) tan (θ /2)
(7.41)
Compton attenuation coefficients
I = I 0 ex p (−μ c x)
(7.42)
If x is in cm then μ c is in cm
−1 ; if x is in g/cm
2 which is obtained by multiplying
x cm by ρ (the density), then μ is 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 = h ν − W
( Einstein’s equation)
(7.43)
where W is the ionization energy of the ejected electron
eV o =
1
2
m ν
2
max = hν − W
(7.43a)
Threshold energy h ν 0 = W
(7.44)
7 Nuclear Physics – I
Maximum shift in wavelength
(Δ λ) max = 2 λ c
(7.38b)
Shift in frequency
ν = ν 0 /(1 + α(1 − cos θ))
(7.39a)
where α = h ν 0 /mc
2
(7.39b)
Δ ν = ν 0 − ν = α ν 0 (1 − cos θ)/(1 + α(1 − cos θ ))
Energy of recoil electron
T = h ν 0 − h ν = α h ν 0 (1 − cos θ)/(1 + α (1 − cos θ ))
(7.40)
Angular relation
cot ϕ = (1 + α) tan (θ /2)
(7.41)
Compton attenuation coefficients
I = I 0 ex p (−μ c x)
(7.42)
If x is in cm then μ c is in cm
−1 ; if x is in g/cm
2 which is obtained by multiplying
x cm by ρ (the density), then μ is 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 = h ν − W
( Einstein’s equation)
(7.43)
where W is the ionization energy of the ejected electron
eV o =
1
2
m ν
2
max = hν − W
(7.43a)
Threshold energy h ν 0 = W
(7.44)