1 / 34

Radiation Basics

Radiation Basics. Mary Lou Dunzik-Gougar, Ph.D. Idaho State University / Idaho National Laboratory Candace C. Davison, M.S. Pennsylvania State University Radiation Science and Engineering Center. What do the following things have in common?. Doctor. Voyager. Soda Can. Bugs.

marisolj
Download Presentation

Radiation Basics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Radiation Basics Mary Lou Dunzik-Gougar, Ph.D. Idaho State University / Idaho National Laboratory Candace C. Davison, M.S. Pennsylvania State University Radiation Science and Engineering Center

  2. What do the following things have in common?

  3. Doctor

  4. Voyager

  5. Soda Can

  6. Bugs

  7. Each represents an application of nuclear science and technology.

  8. What we’ll cover . . . • Atomic Basics • What is Radiation? • Types • Characteristics • Sources of Ionizing Radiation • Concepts • Radioactivity • Half-Life • Contamination vs. Irradiation • Terms

  9. 100 Years of Nuclear Discovery

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

  11. 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 this helium isotope . . . MASS NUMBER is the total number of protons and neutrons 42 He ELEMENT SYMBOL ATOMIC NUMBER is the number of protons

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

  13. Non-Ionizing Radiowaves Microwaves Infrared Ultraviolet Visible Light Types of radiation

  14. Electromagnetic Spectrum

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

  16. Why is it called ionizing? Because it creates ions --atoms with a charge. Ejected Electron Ionizing Radiation

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

  18. What part of atoms? The Nucleus Hence, we have terms such as nuclear science/medicine/reactors.

  19. 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. Radioactive atom

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

  21. Sources of radiation Consumer Products (2%) Cosmic (5%) Nuclear Power (<0.1%) Human Body (5%) The average American receives a radiation dose of 620 millirem per year. Source: National Council on Radiation Protection and Measurement Report 160 (2006)

  22. Units of Dose and Exposure • 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. Perspective

  24. p+ n n p+ Beta () Like an electron Singly negatively or positively charged particle - Gamma () Wave energy (not a particle) Radiation Types Alpha () 2 protons, 2 neutrons Doubly positively charged particle

  25. PENETRATING ABILITY - + + g b a

  26. SHIELDING Concrete alpha beta gamma Lead Wood Paper

  27. 234 90 4 2 a 238 92 U Th + 0 -1 234 90 Pa + b + Th 234 91 n 60m 56 60 56 g Co Co + Radioactive Decay Equations Alpha Decay Beta Decay Gamma Decay

  28. 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

  29. Half Life

  30. Half Life

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

  32. 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

  33. How do we protect ourselves? Time Distance Shielding

  34. The End . . .

More Related