is the process by which an unstable atomic nucleus loses energy by emitting ionizing particles or radiation. The emission is spontaneous in that the nucleus decnt nuclide, transforming to an atom of ays without collision with another particle. This

1
Radioactive decay

• is the process by which an unstable atomic
  nucleus loses energy by emitting ionizing
  particles or radiation. The emission is
  spontaneous in that the nucleus decnt nuclide,
  transforming to an atom of ays without collision
  with another particle. This decay, or loss of
  energy, results in an atom of one type, called
  the parea different type, named the daughter
  nuclide, 14C ------- 15N

2
Radioactive Decay

• Atom (nuclei) yang mempunyai rasio
• proton neutron berada di luar Belt of
• stability secara langsung akan mengalami
• radioactive decay secara Spontan
• Tipe Decay tergantung dimana posisi
• atom berada relative terhadap band of
  stability
• Radioactive particle are emitted with
• different kinetic energy
• - Energy change is related to the change
• in binding energy from reactant to product

3
Band Stability and radioactive Decay
4
(No Transcript)
5
CONTOH NATURAL DECAY
An example is the natural decay chain of 238U
which is as follows decays, through
alpha-emission, with a half-life of 4.5 billion
years to thorium-234 which decays, through
beta-emission, with a half-life of 24 days to
protactinium-234 which decays, through
beta-emission, with a half-life of 1.2 minutes to
uranium-234 which decays, through alpha-emission,
with a half-life of 240 thousand years to
thorium-230 which decays, through alpha-emission,
with a half-life of 77 thousand years to
radium-226 which decays, through alpha-emission,
with a half-life of 1.6 thousand years to
radon-222 which decays, through alpha-emission,
with a half-life of 3.8 days to
polonium-218 which decays, through
alpha-emission, with a half-life of 3.1 minutes
to lead-214 which decays, through beta-emission,
with a half-life of 27 minutes to
bismuth-214 which decays, through beta-emission,
with a half-life of 20 minutes to
polonium-214 which decays, through
alpha-emission, with a half-life of 160
microseconds to lead-210 which decays, through
beta-emission, with a half-life of 22 years to
bismuth-210 which decays, through beta-emission,
with a half-life of 5 days to polonium-210 which
decays, through alpha-emission, with a half-life
of 140 days to lead-206, which is a stable
nuclide.
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
Nuclear Stability and Radioactive Decay
Beta decay
Decrease of neutrons by 1
Increase of protons by 1
Positron decay
Increase of neutrons by 1
Decrease of protons by 1
14
Nuclear Stability and Radioactive Decay
Electron capture decay
Increase of neutrons by 1
Decrease of protons by 1
Alpha decay
Decrease of neutrons by 2
Decrease of protons by 2
Spontaneous fission
HITUNG PERUBAHAN ENERGI BINDING PADA PROSES DECAY
DIATAS ?
23.2
15
Half-Life

• HALF-LIFE is the time that it takes for 1/2 a
  sample to decompose.
• The rate of a nuclear transformation depends only
  on the reactant concentration.

16
Half-Life
Decay of 20.0 mg of 15O. What remains after 3
half-lives? After 5 half-lives?
17

263Sg ----gt 259Rf 4He
18
Terjadi pada Solar Energi dan Proses terjadinya
alam semesta
Terjadi pada proses bom nuklir dan reaktor nuklir
kini
19
(No Transcript)
20
(No Transcript)
21
Kinetics of Radioactive Decay

• For each duration (half-life), one half of the
  substance decomposes.
• For example Ra-234 has a half-life of 3.6
  daysIf you start with 50 grams of Ra-234

After 3.6 days gt 25 grams After 7.2 days gt 12.5
grams After 10.8 days gt 6.25 grams
22
(No Transcript)
23
The probability of decay (-dN/N) is proportional
to dt
The solution to this first-order differential
equation is the following function
Dimana,
The half life is related to the decay constant as
follows
24
(No Transcript)
25
(No Transcript)
26
(No Transcript)
27
(No Transcript)
28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
Kinetics of Radioactive Decay
rate lN
N N0e(-lt)
lnN lnN0 - lt
N the number of atoms at time t
N0 the number of atoms at time t 0
l is the decay constant (sometimes called k)
k
23.3
32
ACTIVITY CALCULATION
N N0e(-lt)
UNTUK HALF LIFE
2,303 Log 0,5/1 -? t½ ? 0,693/t½
A A0e(-l t )
ECERCISE Hitung sisa aktifitas Tritium
setela tersimpan 26 tahun
dari aktifitas semula 15 Ci, t1/2 tritium
12,34 th
33
A sample of C14, whose half life is 5730 years,
has a decay rate of 14 disintegration per minute
(dpm) per gram of natural C. An artifact is found
to have radioactivity of 4 dpm per gram of its
present C, how old is the artifact? Using the
above equation, we have
Where
years
years
34
Kinetics of Radioactive Decay
N N0exp(-lt)
lnN lnN0 - lt
23.3
35
Quantitative Aspect of Radiactive 238U Decay

• Arithmetically, melalui term half life kemudian
  dapat dihitung perubahan
• jumlah/aktivitas zat radioaktive selama
  waktu tertentu
• Graphycally, Mengunakan grafik semilog antara
  Aktivita radioaktiv Vs waktu
• Radioactive Equilibrium
• - Ratio Nomor atom pada proses reaksi
  decay zat radioaktive seperti dibawah ini,
• 238U ?u 234Th
  ?Th 234Pa
• NTh / NU ? U / ?
  Th
• N Th / N U t½ Th
  / t½ U
• - Hal yang sama untuk atome decay dengan
  nomor atom yang kostan , Ratio Massa ebanding
  dengan ratio half life nya,
• Massa X / Massa Y
  t½ X . A X / t½ Y . A Y
• Dari perhitungan ratio nomor atom dan massa
  ada decay reaction maka dapat
• dihitung ratio dari ratio nomor atom dan
  mass dari hasil decay tersebut

36
Nuclear Reaction
37
Balancing Nuclear Equations

• Conserve mass number (A).

The sum of protons plus neutrons in the products
must equal the sum of protons plus neutrons in
the reactants.
235 1 138 96 2x1

• Conserve atomic number (Z) or nuclear charge.

The sum of nuclear charges in the products must
equal the sum of nuclear charges in the reactants.
92 0 55 37 2x0
23.1
38
Nuclear Reactions

• Alpha emission

Note that mass number (A) goes down by 4 and
atomic number (Z) goes down by 2.
Nucleons (nuclear particles protons and
neutrons) are rearranged but conserved
39
Nuclear Reactions

• Beta emission

Note that mass number (A) is unchanged and atomic
number (Z) goes up by 1.
40
Other Types of Nuclear Reactions

• Positron (01b) a positive electron

Electron capture the capture of an electron
41
Artificial Nuclear Reactions

• New elements or new isotopes of known elements
  are produced by bombarding an atom with a
  subatomic particle such as a proton or neutron --
  or even a much heavier particle such as 4He and
  11B.
• Reactions using neutrons are called g reactions
  because a g ray is usually emitted.
• Radioisotopes used in medicine are often made by
  g reactions.

42
Nuclear Bombardment Reactions
Cyclotron or accelerator
Nuclear reactor
43
(No Transcript)
44
ARTIFICIAL TRANSMUTATION TROUGH ACCELERATOR
45
CROSS SECTION

• Is the probability that a bombarding particle
  (neutron) will produce a nuclear reaction
• Cross section Unit is Barn (1 barn 1024 cm-2)
• Formula
• N F x s x nX
• Where, N Total number of reaction
• F Flux neutron
• s nuclear cross section
• n number of nuclei in Cm3
• X is thickness of
  target in Cm

46
Nuclear Cross Section
47
Artificial Nuclear Reactions

• Example of a g reaction is production of
  radioactive 31P for use in studies of P uptake in
  the body.
• 3115P 10n ---gt 3215P g

48
Transuranium Elements

• Elements beyond 92 (transuranium) made starting
  with an g reaction
• 23892U 10n ---gt 23992U g
• 23992U ---gt 23993Np 0-1b
• 23993Np ---gt 23994Pu 0-1b

49
Nuclear Fission
50
Nuclear Fission

• Fission is the splitting of atoms
• These are usually very large, so that they are
  not as stable
• Fission chain has three general steps
• 1. Initiation. Reaction of a single atom
  starts the chain (e.g., 235U neutron)
• 2. Propagation. 236U fission releases neutrons
  that initiate other fissions
• 3. ___________ .

EXCERCISE , REACTION FISSION RANTAI URANIUM
51
Nuclear Fission
Energy mass 235U mass n (mass 90Sr mass
143Xe 3 x mass n ) x c2
Energy 3.3 x 10-11J per 235U
2.0 x 1013 J per mole 235U
Combustion of 1 ton of coal 5 x 107 J
23.5
52
Representation of a fission process.
53
Nuclear Fission
Nuclear chain reaction is a self-sustaining
sequence of nuclear fission reactions.
The minimum mass of fissionable material required
to generate a self-sustaining nuclear chain
reaction is the critical mass.
23.5
54
Diagram of a nuclear power plant
55
(No Transcript)
56
a neutron moderator is a medium that reduces the
speed of fast neutrons, thereby turning them into
thermal neutrons capable of sustaining a nuclear
chain reaction involving uranium-235.
57
A control rod is a rod made of chemical elements
capable of absorbing many neutrons without
fissioning themselves. They are used in nuclear
reactors to control the rate of fission of
uranium and plutonium. Because these elements
have different capture cross sections for
neutrons of varying energies, the compositions of
the control rods must be designed for the neutron
spectrum of the reactor it is supposed to
control. Light water reactors (BWR, PWR) and
heavy water reactors (HWR) operate with "thermal"
neutrons, whereas breeder reactors operate with
"fast" neutrons.
A coolant is a fluid which flows through a device
to prevent its overheating, transferring the heat
produced by the device to other devices that use
or dissipate it. An ideal coolant has high
thermal capacity, low viscosity, is low-cost,
non-toxic, and chemically inert, neither causing
nor promoting corrosion of the cooling system.
Some applications also require the coolant to be
an electrical insulator.
Silver-indium-cadmium alloys, generally 80 Ag,
15 In, and 5 Cd, are a common control rod
material for pressurized water reactors. The
somewhat different energy absorption regions of
the materials make the alloy an excellent neutron
absorber. It has good mechanical strength and can
be easily fabricated. It has to be encased in
stainless steel to prevent corrosion in hot water.
58
Nuclear Fission POWER

• Currently about 103 nuclear power plants in the
  U.S. and about 435 worldwide.
• 17 of the worlds energy comes from nuclear.

59
Nuclear Fusion

• Fusion
• small nuclei combine
• 2H 3H 4He 1n
• 1 1
  2 0
• Occurs in the sun and other stars

Energy
60
Nuclear Fusion
Fusion Reaction
Energy Released
6.3 x 10-13 J
2.8 x 10-12 J
3.6 x 10-12 J
Tokamak magnetic plasma confinement
23.6
61
Nuclear Fusion

• Fusion
• Excessive heat can not be contained
• Attempts at cold fusion have FAILED.
• Hot fusion is difficult to contain

62
(No Transcript)
63
RADIATION CHEMISTRY
Mempelajari efek kimia yang di timbulkan oleh
radiasi pengion bila ia diserap oleh materi
RADIASI Emisi dan propagasi energi dalam
udara dan suatu materi RADIASI PENGION Dapat
mengionkan dan mengeksitasi target (Partikel
bermuatan/ion /elektron, Gel elektromagnetik/gamma
and sinar x, neutron)
IONISASI Pelepasan elektron dari orbital suatu
atom/molekul netral - elektron yang
terikan paling lemah - terbentuk ion
positif dan elektron bebas - hanya
bisa ditimbulkan oleh radiasi pengion
EKSITASI Perpindahan elektron ke orbital lebih
tinggi dalam suatu atom/molekul netral menjadi
atom/molekul mempunyai energi berlebih -
kembali ke tingkat semula dengan disertai emisi
cahaya atau - terjadi pemutusan ikatan
yang lemah menghasilkan radikal bebas
IRADIASI Paparan terhadap radiasi pengion
(berdaya tembus)
64
(No Transcript)
65

Spektrum elektromagnetik
Radiasi pengion
Radiasi non-pengion
Matahari/lampu UV
Matahari/radio isotop
Matahari/pemanas
Pemancar
Matahari/bola pijar
Tabung sinar X
Pemancar/microwave oven
66
(No Transcript)
67
SUMBER RADIASI

• RADIOISOTOPE ALAM DAN BUATAN--------- FOTON DAN
  PARTIKEL
• MESIN PEMERCEPAT (ACCELERATOR) PATIKEL-----
  BERKAS ELEKTRON, BERKAS ION
• REAKTOR NUKLIR --------- BERKAS NETRON

KARAKTERISASI RADIASI PENGION DAYA TEMBUS DAN
LET Radiation pengion mempunyai daya tembus,
tergantung pada jenis radiasi, energi
foton/partikel dan kerapatan target
LET Linier Energy Transer defined as the linier
(distance) rate at which energy is lost by
radiation traversing a material medium in unit
kev/µ
68
Radiasi Sinar Gamma terhadap Materi
DNA Sel Mikroba Patogen terkena radiasi menjadi
tidak mampu berreplikasi dan mati
69
Daya tembus
Sinar gamma gt sinar x gt partikel beta gt partikel
alpha
Partikel alpha gt partikel beta gt sinar x gt sinar
gamma
L E T
70

• Linear energy transfer (LET) is a measure of the
  energy transferred to material as an ionizing
  particle travels through it. Typically, this
  measure is used to quantify the effects of
  ionizing radiation on biological specimens or
  electronic devices.
• Linear energy transfer is closely related to
  stopping power. Whereas stopping power, the
  energy loss per unit distance, dE / dx

71
PROPERTIES OF NUCLEAR RADIATIONS
72
INTERACTION PARTICLE WITH MATTER

• PARTIKEL ALPHA
• - Daya tembus di udara antara 2,5 9 cm
  sedangkan untuk aluminium
• antara 0,02 mm 0,006mm
• - Electrostatic interaction dgn orbital
  electron menghasilkan ionisasi dan
• ion pair (ion positive dan ejected
  electron)
• PARTIKEL BETA
• - Daya tembus 500 kali partikel alpha pada
  energi yang sama
• - Production of ion pair
• - Interaction of fast moving of beta
  particle produced electromagnetic
• radiation (X-ray and gamma ray) near
  positive field of nucleus disertai
• efect bremsstrahlung (slowing down
  radiation)

73
Partikel pengion
IONISASI
EKSITASI
e-
ionisasi
a
e-
elektron
e-
e-
e-
e-
e-
e-
Partikel pengeksitasi
e-
REAKSI INTI
4Be9 2He4 ------------
6C13 1H1
74
INTERAKSI PARTIKEL BETA

• Ionisasi
• Eksitasi
• Bremstrahlung

e-
Sinar x
ß
e-
e-
e-
e-
e-
Elektron dg energi Berkurang /Bremsstraslung
75

• Gamma Rays
• -Photoelectric absorption, gamma photon
  expends all of its
• energy to eject an orbital electron from
  inner shell (beta
• particle), energi foton lt 1MeV seluruhnya
  diserap oleh target
• -Comfton effect, only part of the original
  gamma energy is used
• to eject a bound electron, and partly as
  gamma scattered (energy gamma about 1 - 5 MeV)
• -Pair Production, interaksi menghasilkan
  pasangan elektron-positron (energy gamma about 5
  MeV), konversi foton oleh medan magnet inti
  menjadi elektron dan positron--- akan
  mengionisasi. Elektron dan positron akan
  berannihilasi menghasilkan sinar gamma lemah
  (0,51 MeV) yanh diserap target.

76
Tungsten Target Atom Z 74
K-shell 69.5 keV
M-shell 3 keV
L-shell 12 keV
N-shell 1 keV
O-shell 0.1 keV
Denise Moore, Sinclair Community College
77
Bremsstrahlung Radiation Production

• The projectile electron interacts with the
  nuclear force field of the target tungsten atom
• The electron (-) is attracted to the nucleus ()
• The electron DOES NOT interact with the orbital
  shell electrons of the atom
• Always produced 100 of time

http//www.internaldosimetry.com/courses/introdosi
metry/images/ParticlesBrem.JPG
78
Bremsstrahlung Radiation Production

• As the electron gets close to the nucleus, it
  slows down (brems braking) and changes
  direction
• The loss of kinetic energy (from slowing down)
  appears in the form of an x-ray
• The closer the electron gets to the nucleus the
  more it slows down, changes direction, and the
  greater the energy of the resultant x-ray
• The energy of the x-ray can be anywhere from
  almost 0 (zero) to the level of the kVp

79
X- and Gamma-Ray Interactions

• Rayleigh scattering
• Compton scattering
• Photoelectric absorption
• Pair production

80
Rayleigh Scattering

• Incident photon interacts with and excites the
  total atom as opposed to individual electrons
• Occurs mainly with very low energy diagnostic
  x-rays, as used in mammography (15 to 30 keV)
• Less than 5 of interactions in soft tissue above
  70 keV at most only 12 at 30 keV

81
Rayleigh Scattering
82
Compton Scattering

• Predominant interaction in the diagnostic energy
  range with soft tissue
• Most likely to occur between photons and outer
  (valence) shell electrons
• Electron ejected from the atom photon scattered
  with reduction in energy
• Binding energy comparatively small and can be
  ignored

83
Dowd, S.B. Practical Radiation Protection and
Applied Radiobiology
84
(No Transcript)
85
Compton Scattering
86
Compton scatter probabilities

• As incident photon energy increases, scattered
  photons and electrons are scattered more toward
  the forward direction
• These photons are much more likely to be detected
  by the image receptor, reducing image contrast
• Probability of interaction increases as incident
  photon energy increases probability also depends
  on electron density
• Number of electrons/gram fairly constant in
  tissue probability of Compton scatter/unit mass
  independent of Z

87
Relative Compton scatter probabilities
88
Compton Scattering

• Laws of conservation of energy and momentum place
  limits on both scattering angle and energy
  transfer
• Maximal energy transfer to the Compton electron
  occurs with a 180-degree photon backscatter
• Scattering angle for ejected electron cannot
  exceed 90 degrees
• Energy of the scattered electron is usually
  absorbed near the scattering site

89
Compton Scattering

• Incident photon energy must be substantially
  greater than the electrons binding energy before
  a Compton interaction is likely to take place
• Probability of a Compton interaction increases
  with increasing incident photon energy
• Probability also depends on electron density
  (number of electrons/g ? density)
• With exception of hydrogen, total number of
  electrons/g fairly constant in tissue
• Probability of Compton scatter per unit mass
  nearly independent of Z

90
Photoelectric absorption

• All of the incident photon energy is transferred
  to an electron, which is ejected from the atom
• Kinetic energy of ejected photoelectron (Ec) is
  equal to incident photon energy (E0) minus the
  binding energy of the orbital electron (Eb)
• Ec Eo - Eb

91
Dowd, S.B. Practical Radiation Protection and
Applied Radiobiology
92
Photoelectric absorption (I-131)
93
Photoelectric absorption

• Incident photon energy must be greater than or
  equal to the binding energy of the ejected photon
• Atom is ionized, with an inner shell vacancy
• Electron cascade from outer to inner shells
• Characteristic x-rays or Auger electrons
• Probability of characteristic x-ray emission
  decreases as Z decreases
• Does not occur frequently for diagnostic energy
  photon interactions in soft tissue

94
Photoelectric absorption (I-131)
95
Photoelectric absorption

• Probability of photoelectric absorption per unit
  mass is approximately proportional to
• No additional nonprimary photons to degrade the
  image
• Energy dependence explains, in part, why image
  contrast decreases with higher x-ray energies

96
Photoelectric absorption

• Although probability of photoelectric effect
  decreases with increasing photon energy, there is
  an exception
• Graph of probability of photoelectric effect, as
  a function of photon energy, exhibits sharp
  discontinuities called absorption edges
• Photon energy corresponding to an absorption edge
  is the binding energy of electrons in a
  particular shell or subshell

97
Photoelectric mass attenuation coefficients
98
Photoelectric absorption

• At photon energies below 50 keV, photoelectric
  effect plays an important role in imaging soft
  tissue
• Process can be used to amplify differences in
  attenuation between tissues with slightly
  different atomic numbers, improving image
  contrast
• Photoelectric process predominates when lower
  energy photons interact with high Z materials
  (screen phosphors, radiographic constrast agents,
  bone)

99
Percentage of Compton and photoelectric
contributions
100
Pair production

• Can only occur when the energy of the photon
  exceeds 1.02 MeV
• Photon interacts with electric field of the
  nucleus energy transformed into an
  electron-positron pair
• Of no consequence in diagnostic x-ray imaging
  because of high energies required

101
Pair Production
102
(No Transcript)
103
ABSORPTION OF GAMMA RADIATION

• Attenuation of gamma rays in a material is
  exponential,
• I Io e-µx
• Io adalah Intensitas awal
• I adalah intensitas gamma setelah melalui
  material
• µ adalah koefisien absorption
• X adalah ketebalan material
• X1/2 0.693/µ

104
UNITs

• Counts per minute
• Curie (unit) , Bq
• Gray (unit)
• Rad (unit)
• Rem (unit)
• röntgen (unit)
• Sverdrup (unit) (a unit of volume transport with
  the same symbol Sv as Sievert)
• Background radiation
• Relative Biological Effectiveness
• Radiation poisoning
• Linear Energy Transfer

105
CPM and dpm

• Counts per minute (cpm) is a measure of
  radioactivity. It is the number of atoms in a
  given quantity of radioactive material that are
  detected to have decayed in one minute.
• Disintegrations per minute (dpm) is also a
  measure of radioactivity. It is the number of
  atoms in a given quantity of radioactive material
  that decay in one minute. Dpm is similar to cpm,
  however the efficiency of the radiation detector
• CPM DPM
• DPM Ef Det x CPM

106
UniT RADIOACTIVITY AND DOSE

• One Bq is activity of a quantity of radioactive
  material in which one nucleus decay per second
• SI unit untuk Radioactivity is,
• Bacquerel Bq adalah unit terkecil
• 1 Bq 1 radioactive decay per second
  (S-1) dis/s
• 1 Bq 60 dpm
• Satuan Lama adalah Curie Ci ,
• 1 Ci 3.7 x 1010 Bq 37 GBq
• Bq dapat dalam bentuk sbb
• - kBq , MBq, GBq, TBq and PBq
• Hitung 0,25 Ci dpm ?

107

• Pada pengukuran zat radioaktive dgn alat ukur
  akan terukur unit cps (count per second) or cpm
  (count per minute) dalam bentuk digital. Konversi
  cps ke absolute activity (Bq) adalah
• Bq cps x detektor effesiensi
• Unit of absorbed radiation dose (SI) due to
  ionization radiation (X-ray) is called Gray (Gy)

108

• Absorbed dose (also known as total ionizing dose,
  TID) is a measure of the energy deposited in a
  medium by ionizing radiation. It is equal to the
  energy deposited per unit mass of medium, and so
  has the unit J/kg, which is given the special
  name Gray (Gy).
• 1 Gy of alpha radiation would be much more
  biologically damaging than 1 Gy of photon
  radiation

109
Absorbed dose

• Absorbed dose SI , Gray (Gy, kGy, etc)
• Definition One gray is the absorption of one
  joule of energy, in the form of ionizing
  radiation, by one kilogram of matter
• 1 Gy 1 J/kg
• Absorbed dose Gray (Gy), mengukur deposit
  energi radiasi
• 100 rad 1 Gy

110
Absorbed Dose

• Absorbed dose is the amount of energy absorbed
  into matter. The working SI unit is a gray (Gy),
  while the traditional unit is rad (rad)
• 1 rad 62.4 x 106 MeV per gram1 gray 100 erg
  per gram
• 1 rad 0.01 gray1 gray (Gy) 100 rad
• In the United States, radiation absorbed dose,
  dose equivalent, and exposure are often measured
  and stated in the older units called rad, rem, or
  roentgen (R)

111

• Rongent as radiation exposure equal to the
  ionization radiation will produce one esu of
  electricity in one cc of dry air at oC and
  standard atmosfer
• 1 Gy 115 R
• The röntgen was occasionally used to measure
  exposure to radiation in other forms than X-rays
  or gamma rays
• 1 R 2.5810-4 C/kg (from 1 esu
  3.33564  10-10 C and the standard atmosphere air
  density of 1.293 kg/m³)

112

• The rad (radiation absorbed dose) is a unit of
  absorbed radiation dose
• A dose of 1 rad means the absorption of 100 ergs
  of radiation energy per gram of absorbing
  material
• 1 Gy 100 rad
• 1 roentgen (R) 258 microcoulomb/kg (µC/kg)

113

• When ionising radiation is used to treat cancer,
  the doctor will usually prescribe the
  radiotherapy treatment in Gy. When risk from
  ionising radiation is being discussed, a related
  unit, the sievert is used.

114
equivalent dose

• The equivalent dose (HT) is a measure of the
  radiation dose to tissue where an attempt has
  been made to allow for the different relative
  biological effects of different types of ionizing
  radiation
• Equivalent dose adalah absorbed dose
  biology effect
• Rongent Equivalent
  Man (REM)
• Equivalent dose (HTR) Absorbed dose (Gy) x
  radiation weighting factor (Wr)
• Equivalent dose (SI) ---- Sievert (Sv) unit
  
• Sievert (sv) (biasanya untuk X-ray)
• 100 REM 1 Sv
• 1 Sv 1 J/kg Gy

115
Dose Equivalent

• Dose equivalent is the absorbed dose into
  biological matter taking into account the
  interaction of the type of radiation and its
  associated linear energy transfer through
  specific tissues. The working SI unit is the
  sievert (Sv), while the traditional unit is
  roentgen equivalent man (rem).
• 1Sv 1 rads x quality factor x any other
  modifying factors1rem 1 gray x quality factor
  x any other modifying factors
• 1 Sv 100 roentgen equivalent man (rem)1 rem
  0.01Sv 10mSv

116

• The dose equivalent is a measure of biological
  effect for whole body irradiation. The dose
  equivalent is equal to the product of the
  absorbed dose and the Quality Factor
• The millisievert is commonly used to measure the
  effective dose in diagnostic medical procedures
  (e.g., X-rays, nuclear medicine, positron
  emission tomography, and computed tomography).
  The natural background effective dose rate varies
  considerably from place to place, but typically
  is around 2.4 mSv/year
• that quantity of X rays which when absorbed will
  cause the destruction of the malignant
  mammalian cell

117

• This variation in effect is attributed to the
  Linear Energy Transfer LET of the type of
  radiation, creating a different relative
  biological effectiveness for each type of
  radiation under consideration
• the RBE Q for electron and photon radiation is
  1, for neutron radiation it is 10, and for alpha
  radiation it is 20
• unit of the equivalent dose is the rem (Röntgen
  equivalent man) 1 Sv is equal to 100 rem, for a
  quality factor Q1

118
Q values

• Here are some quality factor values
• Photons, all energies  Q 1
• Electrons all energies  Q 1
• Neutrons,
• energy lt 10 keV  Q 5
• 10 keV lt energy lt 100 keV  Q 10
• 100 keV lt energy lt 2 MeV  Q 20
• 2 MeV lt energy lt 20 MeV  Q 10
• energy gt 20 MeV  Q 5
• Protons, energy gt 2 MeV  Q 5
• Alpha particles and other atomic nuclei  Q 20

119
Other Useful Conversions

• Dose rate criteria (outside storage area)
• 2.5 Sv/hr 0.25mrem/hr
• CNSC Dose Limits (non-Nuclear Energy Worker)
• Whole body 1mSv/yr 100 mrem/yrSkin, Hands,
  Feet 50 mSv/yr 5 rem/yr

120
N values

• Here are some N values for organs and tissues2
• Gonads N 0.20
• Bone marrow, colon, lung, stomach N 0.12
• Bladder, brain, breast, kidney, liver, muscles,
  oesophagus, pancreas, small intestine, spleen,
  thyroid, uterus N 0.05
• Bone surface, skin N 0.01

121

• And for other organisms, relative to humans
• Viruses, bacteria, protozoans N 0.03 0.0003
• Insects N 0.1 0.002
• Molluscs N 0.06 0.006
• Plants N 2 0.02
• Fish N 0.75 0.03
• Amphibians N 0.4 0.14
• Reptiles N 1 0.075
• Birds N 0.6 0.15
• Humans N 1

122
Effective dose
123
(No Transcript)
124
(No Transcript)
125
JUDUL MAKALAH

• Proses Big bang dan pembentukan alam
• Radioaktive decay untuk dating (penanggalan) umur
  batuan (C-14 dan K/Ar)
• Irradiasi gamma untuk sterilisasi produk
  kesehatan dan makanan
• Reaktor nuklir untuk PLTN
• Teknik radiotracer untuk Industri
• Teknik radiasi untuk pertanian
• Laser dan pemanfaatannya untuk kesehatan

126

• Proses pemisahan (enrichment) bahan bakar U235
  dan U238

127
What is This?
128
What is This?
129
What is This?
130
What is This?
131
What is This?
132
What is This?
133
Where Does This Occur?
134
Where Does This Occur?
135
Where Does This Occur?
136
Where Does This Occur?
137
(No Transcript)
138
(No Transcript)