The Secrets of Atomic Radiation

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The Secrets of Atomic Radiation

• by
• Dr. Mohammad Al-Jarallah
• Professor, Department of Physics
• King Fahd University of Petroleum Minerals
• Dhahran, Saudi Arabia
• http//faculty.kfupm.edu.sa/PHYS/mibrahim

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Abstract

• Atomic radiation as a phenomenon is as old as the
  universe itself. It is a normal part of nature
  and life. At this very moment, thousands of rays
  are penetrating your body every second. The
  majority of radiation originates in nature and is
  totally independent of what man does. Today, our
  environment also contains a small amount of extra
  unnatural radiation which is caused by the
  activities of mankind.
• The use of radiation has become an integral part
  of modern life. From the x-ray picture of broken
  limb to the treatment of cancer, the medical
  applications of radiation are now accepted as
  commonplace, and x-ray facilities are available
  in almost every community hospital.
• Radiation contributes in the production of
  electricity, agriculture, and in other industry.
• In my lecture I will try to describe in simple
  terms, what ionizing radiation to which man is
  exposed and second to review its sources and then
  I will shed a light on the applications of
  radiation in different walks of life.

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The Secrets of Atomic Radiation

• The Atom
• Atomic Radiation
• Our Radiation Heritage
• Man Made Radiation
• Application of Atomic Radiation In
• Medicine
• Power Production
• Weapons
• Agriculture
• Industry
• Biological Effects of Radiation
• Radiation Protection
• Summary

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1 - The Atom

• Radiation cannot be understood without knowing a
  little about the structure of the atom, since
  ultimately all radiation originates inside the
  atom. The atom resembles a miniature solar
  system. In the center of the atom is the
  nucleus, while electrons orbit around it, rather
  as planets more around the sun.
• The nucleus contain almost all of the weight and
  substance of the atom it is build up of protons,
  which are about the same size as a proton but do
  not carry an electric charge.
• The electrons in orbit are tiny particles, nearly
  2000 times smaller than a proton or a neutron.
  The inside of the atom is almost all unoccupied
  space!. The analogy with the solar system?

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• The Elements
• The Isotopes
• Molecules

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2 - Atomic Radiation

• Definition of Atomic Radiation
• It is that radiation which has the capability of
  ionizing atoms and molecules, and so cause
  changes which are biologically important.
• Types of Atomic Radiation The main are

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1. ? - Rays
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2. ? - Rays
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3. ? - Rays
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4. X - Rays
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3 - Our Radiation Heritage

• We can classify natural atomic radiation that we
  are exposed to either in terms of their sources
  or their locations in the environment.
• The Sources of Natural Atomic Radiation are
• Cosmic Radiation
• Cosmogenic Radiation
• Naturally Radioactive Series
• Singly occurring Primordial Radionuclies
• Radioactive Ores and By-products (TENORM)
• Radon and Its Progeny

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A. Cosmic Radiation
- Source Outer Space 1- Primary Cosmic
Radiation - 87 protons -11
alpha particles - 2 heavier nuclei
electrons
2- Secondary Cosmic Radiation - pions,
meuons, electrons, photons, protons neutrons
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B. Radioactivity of the Earth
- Mainly ( U-238 series, Th-232 series, K-40
(abundance 0.01 ) )
- In 1 km3 there is about 1 ton K-40
T 1/2 1.28 X 109 yr 4 tons U-238 T 1/2
4.47 X 109 yr 8 tons Th-232 T 1/2 14.1X 109
yr Rb-87 T 1/2 50 X 109 yr
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C. Radioactivity of Air

• Radon its daughters ( Lung Dose )
• - C-14 (1 in 1012 ) T 1/2 5730 yr
• - H-3 T 1/2 12.3 yr
• - Na-22 T 1/2 12.6 yr
• - Be-7 T 1/2 53.3 days

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Decay Series of Uranium-238
238U ?
234Th ? 234Pa? 234U ?
Alpha Decay (4He)
? ? Beta
Decay (e)
230Th ?
226Ra
?
222Rn
?
218Po
?
214Pb? 214Bi? 214Po
?
218P b? 210Bi ? 210Po

?


206Pb
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D. Radioactivity of Water -Sea water K-40
-Spring water U, Th, Ra
E. Radioactivity of the Human Body
- Comes from food water consumption - In the
body K-40, Rb-87,
Ra-226, U-238, Po-210 C-14 - In the Skeleton
Ra-226 - In Bone U-238 Po-210
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4- Man Made Radiation Sources List of Major
Man-Made Radiation Sources
- Nuclear Particle Accelerators. - Nuclear
Reactors. - Isotopic Neutron Sources. - Medical
Syringe Food Sterilization by Radiation. -
Electron Beam.
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A. Fallout - Debris which settles to the earth
as a result of a nuclear blast. - 1 Megatons
device can activate up to 50000 tons of
debris. - These are more than 200 fission
products. - Examples Sr-90 T 1/2 28.1
yr Cs-137 T 1/2 30 yr I-131 T 1/2
8.06 days C-14 T 1/2 5730 yr H-3 T
1/2 12.3 yr
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B. Consumer Products Miscellaneous
Sources
- Wrist Watches Alarm Clocks Ra-226, H-3. -
Tobacco Products Pb-210, Po-210. - Building
Materials U, Th, K-40. - Combustion of Fuels
Ra-226, Th-232, C-14, K-40, U, . - Smoke
Detectors Am-241.
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Consumer Products Miscellaneous
Sources
- Porcelain used for making
dentures K-40 doped with U. - Some rose tinted
eyeglasses contain up to 0.25 Th. - Airport
Luggage Inspection System uses X-rays. -
Television Sets give soft X-rays.
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5 - Application of Atomic Radiation

• A. Medicine

1- Radiation Therapy - In the bast Co-60 -
Now Linear Acceleration up to 23 MeV
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2- Radiology
3- Nuclear Medicine - I-131, Tc-99m, P-32,
Fe-52
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B. Power Production
Radioisotope thermoelectric generator (1000 TBq
90Sr)
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C. Agriculture
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D. Weapons
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E. Industrial Application

• Thickness Gauges for paper, plastic sheets,
  tires, pipe,
• steel, etc. .
• - Moisture Gauges for soil, coke, steel making
  plant.
• - Density Gauges for soil compactor, steel
  making plant.
• - Level Gauges water oil reservoirs.
• - Radiography oil pipes in refinery, airoplanes
• - Mineral Exploration in oil mineral
  exploration.

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Moisture-Density Gauges
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6 - Biological Effects of Radiation
How Radiation can Lead to Damage in Tissue
Radiation
Electrical Effect (Ionization)
Physical Chemical Changes
Damage to DNA
Cell Death
Cell Transformation
Early Effect
Hereditary Defects
Cancer
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7 - Radiation Protection

• The three principles of radiation protection
• Distance
• Time
• Shielding

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8 - Summary

• Atomic radiation as a phenomenon is as old as
  the universe itself. It is a normal part of
  nature and life. At this very moment, thousands
  of rays are penetrating your body every second.
  The majority of radiation originates in nature
  and is totally independent of what man does.
  Today, our environment also contains a small
  amount of extra unnatural radiation which is
  caused by the activities of mankind.

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Thank you