Radiation Basics

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Radiation Basics

• Mary Lou Dunzik-Gougar, PhD
• Idaho State University/Idaho National Laboratory
• ANS Teachers Workshop
• Reno, NV 2014

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Medicine/Health
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Voyager
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Soda Can
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Bugs
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What well cover . . .

• Atomic Basics
• What is Radiation?
• Types
• Characteristics
• Sources of Ionizing Radiation
• Concepts
• Radioactivity
• Half-Life
• Contamination vs. Exposure
• Protection and Biological Effects

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Atomic Structure of Helium
THE HELIUMS subATOMIC
HELIUM ATOM COMPOSITION 2
Protons 2 Neutrons 2 Electrons
e-
p
n
n
p
e-
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More on helium . . .
MASS NUMBER is the total
number of protons and
neutrons
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He
ELEMENT SYMBOL
ATOMIC NUMBER is the number of protons
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What is Radiation?
Transmission of energy via . . . Particles
or Waves
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Types of radiation

• Ionizing
• Alpha
• Beta
• Gamma
• X-Rays
• Neutrons

• Non-Ionizing
• Radiowaves
• Microwaves
• Infrared
• Ultraviolet
• Visible Light

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Why is it called ionizing?
Because it creates ions --atoms with a charge.
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Electromagnetic Spectrum
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Where does radiation come from?
Atoms . . . from radioactive or unstable atoms
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What part of atoms?
The Nucleus Hence, we have terms such as nuclear
medicine.
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What is radioactivity?
The spontaneous emission of fragments or
bundles of energy from energetic nuclei
creating more stable nuclei.
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If radiation comes from atoms and everything is
made of atoms, is there radiation around us right
now?
Absolutely! Its called background radiation
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Sources of Radiation

• Samuel Brinton
• Kansas State University

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In 1987 the average American received 360
millirem of radiation per year
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The average American now receives 620 millirem of
radiation per year
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A Comparison of the Sources
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The Reason for the Change1980s to 2006

• Radiation from medical procedures increased 7
  times.
• Increase in medical imaging procedures
• computed tomography (CT)
• nuclear medicine

Source http//www.ncrponline.org/Publications/160
press.html
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Terms

• Roentgen (R) - unit of exposure - ionization of
  air by x or gamma rays
• RAD (Radiation Absorbed Dose) - energy deposited
  in material
• rem - (Roengten Equivalent Man)
• unit of dose equivalent

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Radiation Types

• Alpha (?)
• 2 protons, 2 neutrons
• positively charged particle

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PENETRATING ABILITY
-


g
b
a
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SHIELDING
Concrete
alpha
beta
gamma
Lead
Wood
Paper
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RADIOACTIVE DECAY REACTIONS
ALPHA DECAY BETA DECAY GAMMA DECAY
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Units of Activity
Activity - a rate the number of emissions (of
radiation) per unit time. dps -
disintegrations per second Bequerel 1 dps
Curie 37,000,000,000 dps Picocurie 0.037 dps
or 2.2 dpm
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Radioactive Contamination
Radioactive Contamination - is radioactive
material in an unwanted place.
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Half Life
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Half Life
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Why are we concerned about Radiation?
Ionizing Radiation
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How do we protect ourselves?
Time
Distance
Shielding
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The End . . .