From my class on nuclear physics for nuclear medicine technologists. This class covers alpha, beta, and gamma decay, plus conversion electrons, Auger electrons, and k-alpha and other X-rays

1. Radioactive Decay

3. b ig
T oo
ns
o to
pr
a ny ns
m tro
Too n eu
a ny
m
T oo

9. Dataset #2:
Authors: J. K. TULI, G. REED, B. SINGH Citation: Nuclear Data Sheets 93, 1 (2001)
Parent Parent Parent Parent GS-GS Q-value Daughter
Decay Mode
Nucleus E(level) J" T 1/2 (keV) Nucleus
Decay
Scheme
99 99
Tc 14 2 . 6 8 3 2 1 1 1/2- 6.015 h 9 I T : 9 9 . 9 9 63 6 % Tc
43 43
Electrons:
Energy Intensity Dose
(keV) (%) ( MeV/Bq-s )
CE M 1.6286 11 74.595 % 0.0012149
Auger L 2.17 10.32 % 6 2 . 2 4 0 E - 4 14
Auger K 15.5 2.05 % 4 3.17E-4 6
CE K 119.4670 12 8.84 % 0.01056
CE K 121.59 3 0.55 % 5 6.7E-4 6
CE L 137.4685 11 1.07 % 0.00147
CE L 139.59 3 0.172 % 16 2.40E-4 23
CE M 139.9670 14 0.194 % 2.72E-4
CE NP 140.4430 22 0.0374 % 5.25310E-5
CE M 142.09 3 0.034 % 3 4.8E-5 5
CE NP 142.56 3 0.0066 % 6 9.4E-6 9
Gamma and X-ray radiation:
Energy Intensity Dose
(keV) (%) ( MeV/Bq-s )
2.1726 4 6.201E-9 % 1.347E-13
XR l 2.42 0.447 % 11 1.08E-5 3
X R k #2 18.251 2.14 % 6 3.91E-4 11
X R k #1 18.367 4.07 % 12 7.47E-4 21
X R k !3 20.599 0.330 % 10 6.79E-5 20
X R k !1 20.619 0.639 % 18 1.32E-4 4
X R k !2 21.005 0.145 % 4 3.04E-5 8
140.511 1 89.06 % 0.1251
142.63 3 0.0187 % 18 2.7E-5 3

10. A conversion electron is ejected by
a gamma photon from the nucleus

11. A conversion electron is ejected by
a gamma photon from the nucleus

12. A kα X-ray comes when an
electron from the L shell falls to
the K shell

13. A kα X-ray comes when an
electron from the L shell falls to
the K shell

14. An Auger electron is ejected by a
kα X-ray

15. An Auger electron is ejected by a
kα X-ray

16. Gamma decay comes when nucleus falls
from high energy state to low energy state
Gamma rays can be absorbed by electrons
in the atom
Conversion electron: Gamma ray ejects
electron
k-α, L-β X-ray radiation when electrons
from high shells fall to low shells
Auger electrons when k-α absorbed by
outer electrons, ejecting them.

17. Gamma decay comes when nucleus falls
from high energy state to low energy state
Gamma rays can be absorbed by electrons
in the atom
Conversion electron: Gamma ray ejects
electron
k-α, L-β X-ray radiation when electrons
from high shells fall to low shells
Auger electrons when k-α absorbed by
outer electrons, ejecting them.

19. Alpha decay energy

20. MP (MD MHe ) 11-34
c2
Note that the mass of the two electrons in the He atom compensates for the fact
that the daughter atom has two fewer electrons than the parent atom. Applying this
to the example given in Equation 11-33, the mass of the 232Th atom is 232.038124 u
The mass of the daughter atom 228Ra is 228.031139 u, and adding it to the 4.002603
u mass of 4He, we get 232.033742 u for the total mass of the decay products
Equation 11-34 then yields Q/c 2 0.004382 u, which, when multiplied by the con-
version factor 931.5 MeV/c 2, gives Q 4.08 MeV. Thus, the rest energy of 232Th
is greater than that of 228Ra 4He; therefore, 232Th is unstable toward spontaneous
decay.
The kinetic energy of the particle (for decays to the ground state of the daugh-
ter nucleus) is slightly less than the decay energy Q because of the small recoil energy
of the daughter nucleus. If the parent nucleus is at rest when it decays, the daughter
1600
!286
Number of particles
1200 !61
!0
800
!334
!330
400 !
!376 342 !247 !174 !80
!350 !30
!280 !235 !124
5.70 5.80 5.90 6.00
Energy, MeV

23. Alpha decay when nucleus is too large
Alpha particles emitted at specific energies
Not dangerous from outside: can’t penetrate
skin
Dangerous when ingested/inhaled
Gamma decay comes when nucleus falls
from high energy state to low energy state
Gamma rays can be absorbed by electrons
in the atom
Conversion electron: Gamma ray ejects
electron
k-α, L-β X-ray radiation when electrons
from high shells fall to low shells
Auger electrons when k-α absorbed by
outer electrons, ejecting them.

24. Alpha decay when nucleus is too large
Alpha particles emitted at specific energies
Not dangerous from outside: can’t penetrate
skin
Dangerous when ingested/inhaled
Gamma decay comes when nucleus falls
from high energy state to low energy state
Gamma rays can be absorbed by electrons
in the atom
Conversion electron: Gamma ray ejects
electron
k-α, L-β X-ray radiation when electrons
from high shells fall to low shells
Auger electrons when k-α absorbed by
outer electrons, ejecting them.

26. _
n p + e– + ν
p n + e+ + ν
p + e– n+ ν
n ν
p+ β-

30. Dataset #3:
Author: E. BROWNE Citation: Nuclear Data Sheets 82, 379 (1997)
Parent Parent Parent Parent GS-GS Q-value Daughter
Decay Mode
Nucleus E(level) J! T1/2 (keV) Nucleus
Decay
90 90 Scheme
39
Y 0 2- 64.00 h 21 "- : 100 % 2280.1 16
40
Zr
Beta-:
Energy End-point energy Intensity Dose
(keV) (keV) (%) ( MeV/Bq-s )
25.0 7 93.8 16 1.4E-6 % 3 3.5E-10 8
185.6 10 519.4 16 0.0115 % 14 2.1E-5 3
933.7 12 2280.1 16 99.9885 % 14 0.9336 12
Mean beta- energy: 933.6 keV 12, total beta- intensity: 100.0000 % 20, mean beta- dose:
0.9336 MeV/Bq-s 12

34. Decay radiation

37. n
udd
νe
e+
W+
u du
p

38. Positron decay makes
back-to-back photons
–
+
TOTAL
Energy: 2mc2 = 1022 keV
Charge: 0
Momentum: 0

39. Positron decay makes
back-to-back photons
1 keV
= 51 11
hν +5
1k
eV
– g y: : 0
er ge h/λ
=
51 En ar m:
: hν
= 511 h entu
gy : 0
er ge λ=
- + C m
Mo
n r
E a : h/
Ch men tum
Mo TOTAL
Energy: 2mc2 = 1022 keV
Charge: 0
Momentum: 0

42. Authors: TILLEY, WELLER, CHEVES, CHASTELER Citation: Nuclear Physics A595, 1 (1995)
Parent Parent Parent Parent GS-GS Q-value Daughter
T1/2 Decay Mode
Nucleus E(level) J! (keV) Nucleus
Decay
18 18 Scheme
9
F 0 1+ 109.77 m 5 " + : 100 % 1655.50 63
8
O
Beta+:
Energy End-point energy Intensity Dose
(keV) (keV) (%) ( MeV/Bq-s )
249.8 3 633.5 6 96.73 % 4 0.2416 3
Mean beta+ energy: 249.8 keV 3, total beta+ intensity: 96.73 % 4, mean beta+ dose: 0.2416 MeV/Bq-s 3
Electrons:
Energy Intensity Dose
(keV) (%) ( MeV/Bq-s )
Auger K 0.52 3.072 % 11 1.597E-5 6
Gamma and X-ray radiation:
Energy Intensity Dose
(keV) (%) ( MeV/Bq-s )
XR k#2 0.525 0.009 % 3 4.5E-8 18
XR k#1 0.525 0.017 % 7 9E-8 4
Annihil. 511.0 193.46 % 8

43. Positron decay requires enough initial
energy to make a positron
p + e– n + ν p n + e+ + ν
mp+me+Q = mn+Eout mp+Q = mn+me+Eout
n ν
p+ β-

46. Parent Parent Parent Parent GS-GS Q-value Daughter
T1/2 Decay Mode
Nucleus E(level) J! (keV) Nucleus
Decay
57 57 Scheme
Co 0.0 7/2- 271.74 d 6 ": 100 % 836.0 4 Fe
27 26
Electrons:
Energy Intensity Dose
(keV) (%) ( MeV/Bq-s )
Auger L 0.67 251 % 4 0.001684 24
Auger K 5.62 105.1 % 17 0.00591 10
CE K 7.3009 11 71.1 % 24 0.00519 18
CE L 13.5668 7 7.4 % 3 1.00E-3 3
CE K 114.9487 9 1.83 % 10 0.00211 12
CE L 121.2146 4 0.192 % 17 2.32E-4 21
CE K 129.3616 9 1.30 % 14 0.00169 18
Gamma and X-ray radiation:
Energy Intensity Dose
(keV) (%) ( MeV/Bq-s )
XR l 0.7 1.52 % 15 1.06E-5 11
XR k#2 6.391 16.6 % 9 0.00106 5
XR k#1 6.404 32.9 % 15 0.00211 10
XR k$1 7.058 3.91 % 19 2.76E-4 13
XR k$3 7.058 2.00 % 10 1.41E-4 7
14.4129 6 9.16 % 15 0.001320 22
122.06065 12 85.60 % 17 0.10448 21
136.47356 29 10.68 % 8 0.01458 11
230.4 4 4E-4 % 4 9E-7 9
339.69 21 0.0037 % 3 1.26E-5 10
352.33 21 0.0030 % 3 1.06E-5 11

47. Alpha decay when nucleus is too large
Alpha particles emitted at specific energies
Not dangerous from outside: can’t penetrate
skin
Dangerous when ingested/inhaled
Beta decay: neutron turned into proton or
proton turned into neutron
Neutrino takes some energy: beta particle
has range of energies
Positron decay makes annihilation photons
Electron capture: nucleus grabs low-lying
electron
Gamma decay comes when nucleus falls
from high energy state to low energy state
Gamma rays can be absorbed by electrons
in the atom
Conversion electron: Gamma ray ejects
electron
k-α, L-β X-ray radiation when electrons
from high shells fall to low shells
Auger electrons when k-α absorbed by
outer electrons, ejecting them.

48. Alpha decay when nucleus is too large
Alpha particles emitted at specific energies
Not dangerous from outside: can’t penetrate
skin
Dangerous when ingested/inhaled
Beta decay: neutron turned into proton or
proton turned into neutron
Neutrino takes some energy: beta particle
has range of energies
Positron decay makes annihilation photons
Electron capture: nucleus grabs low-lying
electron
Gamma decay comes when nucleus falls
from high energy state to low energy state
Gamma rays can be absorbed by electrons
in the atom
Conversion electron: Gamma ray ejects
electron
k-α, L-β X-ray radiation when electrons
from high shells fall to low shells
Auger electrons when k-α absorbed by
outer electrons, ejecting them.