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Radiation Basics

Radiation Basics. Mary Lou Dunzik-Gougar, PhD Idaho State University/Idaho National Laboratory ANS Teachers’ Workshop Reno, NV 2014. Medicine/Health. Voyager. Soda Can. Bugs. What we’ll cover. Atomic Basics What is Radiation? Types Characteristics Sources of Ionizing Radiation

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Radiation Basics

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  1. Radiation Basics Mary Lou Dunzik-Gougar, PhD Idaho State University/Idaho National Laboratory ANS Teachers’ Workshop Reno, NV 2014

  2. Medicine/Health

  3. Voyager

  4. Soda Can

  5. Bugs

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

  7. Atomic Structure of Helium THE HELIUM’S subATOMIC HELIUM ATOMCOMPOSITION 2 Protons 2 Neutrons 2 Electrons e- p+ n n p+ e-

  8. Protons have a large mass and a positive charge. The number of protons identifies an element. p+ Neutrons have a large mass approximately equal to a proton’s mass. Neutrons have no charge. n Electrons have a very small mass and a negative charge. Electrons travel outside the nucleus. e- More on helium . . . MASS NUMBER is the total number of protons and neutrons 42 He ELEMENT SYMBOL ATOMIC NUMBER is the number of protons

  9. What is Radiation? Transmission of energy via . . . Particles or Waves

  10. Ionizing Alpha Beta Gamma X-Rays Neutrons Non-Ionizing Radiowaves Microwaves Infrared Ultraviolet Visible Light Types of radiation

  11. Neutrons and Protons Ejected Electron Ionizing Radiation Why is it called ionizing? Because it creates ions --atoms with a charge.

  12. Electromagnetic Spectrum

  13. Where does radiation come from? Atoms . . . from radioactive or unstable atoms

  14. What part of atoms? The Nucleus Hence, we have terms such as nuclear medicine.

  15. Radioactive atom Energy and radiation released More stable atom formed What is radioactivity? The spontaneous emission of “fragments” or “bundles” of energy from energetic nuclei creating more stable nuclei.

  16. If radiation comes from atoms and everything is made of atoms, is there radiation around us right now? Absolutely! It’s called background radiation

  17. Sources of Radiation Samuel Brinton Kansas State University

  18. In 1987 the average American received 360 millirem of radiation per year

  19. The average American now receives 620 millirem of radiation per year

  20. A Comparison of the Sources

  21. 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/160press.html

  22. 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

  23. p+ n n p+ • Beta () • like an electron • negatively charged particle - • Gamma () • Wave energy (not a particle) Radiation Types Alpha () 2 protons, 2 neutrons positively charged particle

  24. PENETRATING ABILITY - + + g b a

  25. SHIELDING Concrete alpha beta gamma Lead Wood Paper

  26. 234 90 4 2 238 92 a U Th + 0 -1 Pa + b + 234 90 Th 234 91 n 137 56 g 137m 56 Ba Ba + RADIOACTIVE DECAY REACTIONS ALPHA DECAY BETA DECAY GAMMA DECAY

  27. 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

  28. Radioactive Contamination Radioactive Contamination- is radioactive material in an unwanted place.

  29. Half Life

  30. Half Life

  31. Human Cells Atoms in Cells Form Ions No/Neutral Change in Cell Change in Cell Cell Dies Reproduces Replaced Malignant Growth Benign Growth Not Replaced Why are we concerned about Radiation? Ionizing Radiation

  32. How do we protect ourselves? Time Distance Shielding

  33. The End . . .

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