Nuclear Radiation Basics

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• Nuclear Radiation Basics

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Contents

• What is Radiation?
• Instruments that Measure Nuclear Radiation
• Nuclear Radiation Sensors
• International Medcom Products

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What is Radiation?
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What is Radiation?

• Radiation is energy transmitted as particles or
  waves.
• Ionizing radiation
• Nuclear radiation alpha, beta, gamma, neutron
  and x-ray
• Non-ionizing radiation
• Visible light
• Infrared light
• Microwaves
• Radio waves
• Radar

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What is Radiation?
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• Alpha particles
• Positively charged particles (2 protons 2
  neutrons)
• Relatively heavy in mass
• Cannot penetrate very far but the radionuclides
  that emit them can be carried by wind
• Can be stopped by paper
• Energy ranges from 2.5 MeV to 5.5 MeV
• Sample emitters Plutonium 239 and Americium 241

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What is Radiation?
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• Beta particles
• Negatively charged particles
• Relatively light in mass
• Can penetrate more deeply than alpha particles
• Can be stopped by a few millimeters of aluminum
• Energy ranges from 7 keV to 2.2 MeV
• Sample emitters Carbon 14 and Strontium 90

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What is Radiation?
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• Gamma rays
• Waves that have no charge and no mass
• Can be much more penetrating than alpha or beta
  particles
• Most can be stopped by thick concrete or lead
• Energy ranges from 10 keV to several MeV
• Sample emitters Barium 140 and Cobalt 60

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What is Radiation?

• X-rays
• Waves that have no charge or mass
• Characteristics are the same as gamma rays
• Difference x-rays are generally man made and
  gamma rays occur naturally

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What is Radiation?

• Neutron particles
• No charge
• Relatively high mass
• More penetrating than alpha and beta particles
  but less penetrating than gamma rays
• Can be stopped by thick concrete or lead
• Energy ranges from 40 keV to 35 MeV
• Sample emitters Plutonium 239 (man-made)

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Instruments that Measure Nuclear Radiation
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Instruments that Measure Nuclear Radiation

• Rate Meter
• Measures amount of radiation per time period
  continuously with frequent updating
• Users
• First responders
• Laboratory workers
• Homeowners
• Some have a manual or pre-set alarm function
• Most have an analog or digital readout

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Instruments that Measure Nuclear Radiation

• Dosimeter
• Measures the dose of radiation a person receives
  over a period of time
• Active dosimeters can be read in real time
• Passive dosimeters cannot be read in real time
• Users
• nuclear reactor staff
• researchers
• Some active dosimeters have a manual or pre-set
  alarm function

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Instruments that Measure Nuclear Radiation

• Multi-Channel Analyzer or Spectrometer
• Determines what radionuclides are present and in
  what amounts
• Users
• Border control
• Shipping
• First responders (when abnormal radiation levels
  are detected)
• Readout is on a built in screen or connected to a
  computer with special software

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Nuclear Radiation Sensors
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Nuclear Radiation Sensors

• Geiger-Mueller Tube (GM tube)
• Can detect alpha (with a mica window), beta,
  gamma and x-rays
• Can detect energy levels between 15 keV and 10
  MeV
• Advantages
• Small
• Lightweight
• Relatively inexpensive

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Nuclear Radiation Sensors

• Energy Compensated Geiger-Mueller Tubes
• Detect only gamma and x-rays
• Can typically detect energy levels between 100
  keV and 10 MeV
• Disadvantages
• Heavier than standard GM tube devices
• More expensive than standard GM tube devices
• Cannot detect alpha or beta or low energy gamma
  radiation

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Nuclear Radiation Sensors

• Scintillation Sensors
• Typically detects gamma and x-rays, but some can
  detect alpha and beta radiation
• Can detect energy levels between 10 keV and 10
  MeV, usually not in one sensor
• Disadvantages
• More expensive than GM tubes
• Must know in advance what you are trying to
  detect to get the right energy range device

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Nuclear Radiation Sensors

• Other sensors
• Ionization chambers
• Solid state (including Cadmium Telluride and
  Silicon)
• Proportional counters
• Thermoluminescent dosimeter and film badges

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International Medcom Products
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International Medcom Products

• Radalert 50
• Rate meter
• Geiger-Mueller sensor with ½ inch mica end
  window
• LCD
• Adjustable alert feature
• 1 minute update
• Audible chirp for each count (can be muted)
• 9 volt battery

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International Medcom Products

• Inspector
• Rate Meter
• 2 inch pancake tube Geiger-Mueller sensor with
  mica window
• LCD
• 3 second update
• Audible chirp for each count (can be muted)
• 9 volt battery

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International Medcom Products

• Inspector EXP
• Rate Meter
• External probe has 2 inch pancake tube
  Geiger-Muller sensor with mica window
• LCD
• 3 second update
• Audible chirp for each count (can be muted)
• 9 volt battery