Introduction to Radiation Fundamentals

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Introduction to Radiation Fundamentals
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Radiation Fundamentals

• Objectives.
• Atomic Structure
• Fundamentals of Ionizing Radiation
• Radiation Injury
• Radiation Sources
• Radiation Protection Practices
• Radiation Detection

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Protons - Positive Charge - 1 AMU -
determines element Neutron - Neutral Charge
- Nuclear Glue to hold nucleus together - 1
AMU Electron - Negative Charge - Orbits
nucleus - determines atoms reactivity
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Ionizing Radiation
Radiations that can transfer enough energy to
remove electrons from their atoms are referred to
as Ionizing Radiations
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Ionizing Radiation
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Alpha Particles
Most Common decay mode for heavy
nuclides. Particle has a mass of 4 AMU Carries a
2 charge Although emitted at high energies, 4-6
million electron volts (MeV), because of it size
and charge it is not very penetrating. Minimal
External Hazard Primarily an Internal Hazard
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Beta Particles
Electron emitted from the nucleus. Can be
positive or negatively charged. Emitted with a
spectrum of energies, can be difficult to
determine proper protective devices. As a
particle, penetrability is limited but greater
than that of an alpha particle. External Hazard
and Internal Hazard based on energy.
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Gamma Radiations
Massless packet of energy Byproduct of a
particulate decay Carries no charge Emitted at
energies characteristic to the parent
nucleus. Very penetrating radiation capable of
causing internal damage with requiring the source
to be internalized.
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Radiation Injury

• Risk from Exposure
• Acute exposure -vs- effect is well documented
• Large doses received over short duration
• Effects on individual exposed
• Chronic exposure -vs- effect more obscure
• No cancer increases at occupational exposures
• Potential can not be dismissed
• High natural occurrence of cancer

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Radiation Injury
Average estimated days lost due to daily
activities
Occupation (Activity) Days of Life Lost
Being an unmarried male 3,500
Smoking (1 pack/day) 2,250
Being an unmarried female 1,600
Being a coal miner 1,100
Being 25 overweight 777
Drinking alcohol (US average) 365
Being a construction worker 227
Driving a motor vehicle 207
All industry (average) 60
Being exposed to 100 mrem/yr 10
Drinking coffee 6
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Radiation Sources

• Background Radiation Exposures received by all
  living beings.
• Contributions from natural sources as well as
  from man made sources.

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Natural Sources
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Man-Made Sources
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Radioactive Decay
Atoms that have excess energy within the nucleus
will go through a decay emitting its excess
energy in the form of a particulate or
electromagenetic radiation. In many instances, a
single decay does not result in a stable atom.
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Half-Life
Radioactive materials all decay with a
characteristic rate of decay. The term half-life
is used to identify the time required for a
quantity of radioactive atoms to decay to half of
the original number of atoms.
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Principles of Protection

• Time
• Dose is base on exposure time, therefore if you
  minimize your time you minimize your dose.
• Distance Intensity decreases greatly with
  increase in distance from the source.
• Shielding- placing the proper materials between
  you and the source can decrease your dose.

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Radiation Detection
Not detectable with our senses. Detection is
performed through the measurement of the
ionization created in a detecting chamber.