Types of radioactive decay

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. Too many protons
Too many neutrons
Too big

9. 7/13/09 10:25 AMDecay Radiation Results
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XR k!1 21.657 8.54E-5 % 24 1.85E-8 5
XR k!2 22.074 2.00E-5 % 6 4.42E-9 13
89.6 3 S 0.0010 % 9.3E-7
232.8 2 8.5E-6 % 20 2.0E-8 5
322.4 2 9.7E-5 % 17 3.1E-7 5
Dataset #2:
Authors: J. K. TULI, G. REED, B. SINGH Citation: Nuclear Data Sheets 93, 1 (2001)
Parent
Nucleus
Parent
E(level)
Parent
J"
Parent
T
1/2
Decay Mode
GS-GS Q-value
(keV)
Daughter
Nucleus
Decay
Scheme
99
43
Tc 142.6832 11 1/2- 6.015 h 9 IT: 99.9963 6 %

99
43
Tc

Electrons:
Energy
(keV)
Intensity
(%)
Dose
( MeV/Bq-s )
CE M 1.6286 11 74.595 % 0.0012149
Auger L 2.17 10.32 % 6 2.240E-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
(keV)
Intensity
(%)
Dose
( MeV/Bq-s )
2.1726 4 6.201E-9 % 1.347E-13
XR l 2.42 0.447 % 11 1.08E-5 3
XR k#2 18.251 2.14 % 6 3.91E-4 11
XR k#1 18.367 4.07 % 12 7.47E-4 21
XR k!3 20.599 0.330 % 10 6.79E-5 20
XR k!1 20.619 0.639 % 18 1.32E-4 4
XR 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
Dataset #3:
Author: L. K. PEKER Citation: Nuclear Data Sheets 73,1 (1994)
Parent
Nucleus
Parent
E(level)
Parent
J"
Parent
T
1/2
Decay Mode
GS-GS Q-value
(keV)
Daughter
Nucleus

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. 400
1200
800
1600
Energy, MeV
!
235
!
247
!
286
!
280
!
330
!
334
!
342
!
350
!
376 !
174
!
124
!
80
!
30
!
61
!
0
5.70 5.90 5.80 6.00
Number of particles
short
standard
long
37480 Tipler(Freem) LEFT INTERACTIVE
top of RH
base of RH
top of txt
base of txt
MoreMore
EnergeticsofAlphaDecay
The energy released in!decay,Q, is determined by the difference in mass of the
parent nucleus and the decay products, which include the daughter nucleus and the
!particle. Consider the decay of
232
Th (Z!90) into
228
Ra (Z!88) plus an!particle.
This is written as
232 228 228 4
Th!: Ra"! (!Ra"He) 11-33
The energyQis usually expressed in terms of atomic masses (which include the
masses of the electrons) because, as explained earlier, these are the masses measured
in mass spectroscopy. IfM
Pis the mass of the parent atom,M
Dthat of the daughter
atom, andM
Hethat of the helium atom, the decay energyQis given by conservation
of mass energy as
Q
!M#(M"M) 11-34
PD He
2
c
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
232
Th atom is 232.038124 u.
The mass of the daughter atom
228
Ra is 228.031139 u, and adding it to the 4.002603
u mass of
4
He, we get 232.033742 u for the total mass of the decay products.
Equation 11-34 then yieldsQ/c
2
!0.004382 u, which, when multiplied by the con-
version factor 931.5 MeV/c
2
, givesQ!"4.08 MeV. Thus, the rest energy of
232
Th
is greater than that of
228
Ra"
4
He; therefore,
232
Th 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 energyQbecause of the small recoil energy
of the daughter nucleus. If the parent nucleus is at rest when it decays, the daughter
Fig. 11-19Alpha-particle
spectrum from
227
Th. The
highest-energy!particles
correspond to decay to the
ground state of
223
Ra with a
transition energy ofQ!6.04
MeV. The next highest energy
particles,!
30, result from
transitions to the first excited
state of
223
Ra, 30 keV above
the ground state. The energy
levels of the daughter nucleus,
223
Ra, can be determined by
measurement of the!-particle
energies.
Continued

23. 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.
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

24. 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.
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

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

+ ν

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XR k!1 16.738 0.581 % 21 9.7E-5 3
XR k!2 17.013 0.111 % 4 1.90E-5 7
202.53 3 97.3 % 4 0.1970 7
479.51 5 90.74 % 5 0.43510 24
681.8 6 0.32 % 3 0.00217 19
Dataset #2:
Author: E. BROWNE Citation: Nuclear Data Sheets 82, 379 (1997)
Parent
Nucleus
Parent
E(level)
Parent
J"
Parent
T
1/2
Decay Mode
GS-GS Q-value
(keV)
Daughter
Nucleus
Decay
Scheme
90
39
Y 682.04 2 7+ 3.19 h 1 !
-
2280.1 16

90
40
Zr

Beta-:
Energy
(keV)
End-point energy
(keV)
Intensity
(%)
Dose
( MeV/Bq-s )
232.5 10 643.2 16 0.0018 % 3 4.2E-6 7
Mean beta- energy: 2.3E+2 keV 5, total beta- intensity: 0.0018 % 3, mean beta- dose: 4.2E-6 MeV/Bq-s 11
Gamma and X-ray radiation:
Energy
(keV)
Intensity
(%)
Dose
( MeV/Bq-s )
2318.968 10 0.00180 % 4.2E-5
Dataset #3:
Author: E. BROWNE Citation: Nuclear Data Sheets 82, 379 (1997)
Parent Parent Parent Parent
T
1/2
Decay Mode
GS-GS Q-value Daughter
7/10/09 11:04 AMDecay Radiation Results
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Gamma and X-ray radiation:
Energy
(keV)
Intensity
(%)
Dose
( MeV/Bq-s )
2318.968 10 0.00180 % 4.2E-5
Dataset #3:
Author: E. BROWNE Citation: Nuclear Data Sheets 82, 379 (1997)
Parent
Nucleus
Parent
E(level)
Parent
J!
Parent
T
1/2
Decay Mode
GS-GS Q-value
(keV)
Daughter
Nucleus
Decay
Scheme 90
39
Y 0 2- 64.00 h 21 "
-
: 100 % 2280.1 16

90
40
Zr

Beta-:
Energy
(keV)
End-point energy
(keV)
Intensity
(%)
Dose
( 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
Electrons:
Energy Intensity Dose

34. Decay radiation

37. p
n
e
+
νe
uu
udd
d
W
+

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

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

= 511 keV
Charge: 0
Momentum: h/λ = +511
Energy: hν

= 511 keV
Charge: 0
Momentum: h/λ = -511

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Search parameters:
Nucleus:18F
Results:
Dataset #1:
Authors: TILLEY, WELLER, CHEVES, CHASTELER Citation: Nuclear Physics A595, 1 (1995)
Parent
Nucleus
Parent
E(level)
Parent
J!
Parent
T
1/2
Decay Mode
GS-GS Q-value
(keV)
Daughter
Nucleus
Decay
Scheme 18
9
F 0 1+ 109.77 m 5 "
+
: 100 % 1655.50 63

18
8
O

Beta+:
Energy
(keV)
End-point energy
(keV)
Intensity
(%)
Dose
( 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
(keV)
Intensity
(%)
Dose
( MeV/Bq-s )
Auger K 0.52 3.072 % 11 1.597E-5 6
Gamma and X-ray radiation:
Energy
(keV)
Intensity
(%)
Dose
( 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. p
+
β
-
νn
p N n + e
+
+ νp + e
–
N n

+ ν
mp+me+Q = mn+Eout
mp+Q = mn+me+Eout
Positron decay requires enough initial
energy to make a positron

46. 7/13/09 10:45 AMDecay Radiation Results
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Search parameters:
Nucleus:57CO
Results:
Dataset #1:
Author: M. R. BHAT Citation: Nuclear Data Sheets 85, 415 (1998)
Parent
Nucleus
Parent
E(level)
Parent
J!
Parent
T
1/2
Decay Mode
GS-GS Q-value
(keV)
Daughter
Nucleus
Decay
Scheme 57
27
Co 0.0 7/2- 271.74 d 6 ": 100 % 836.0 4

57
26
Fe

Electrons:
Energy
(keV)
Intensity
(%)
Dose
( 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
(keV)
Intensity
(%)
Dose
( 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. 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.
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

48. 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.
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