1 / 36

Radiation Basics

Radiation Basics. Candace C. Davison, M.Engr. Research & Education Specialist Pennsylvania State University Radiation Science and Engineering Center Mary Lou Dunzik-Gougar, Ph.D. Assistant Prof of Nuclear Engineering Idaho State University / Idaho National Laboratory. Medicine/Health.

lillyj
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 Candace C. Davison, M.Engr. Research & Education Specialist Pennsylvania State University Radiation Science and Engineering Center Mary Lou Dunzik-Gougar, Ph.D. Assistant Prof of Nuclear Engineering Idaho State University / Idaho National Laboratory

  2. Medicine/Health

  3. Voyager

  4. Soda Can

  5. Bugs

  6. Questions we’ll answer. . . • What is Radiation? • Where does it come from? • What is Radioactivity? • What’s the difference betweenContamination and Irradiation? • How does radiation interact?

  7. Remember atomic structure? 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. p+ Electrons have a very small mass and a negative charge. Electrons travel outside the nucleus. e- More on this helium isotope . . . MASS NUMBER is total number of protons and neutrons 4 2 Neutrons have large mass, approximately equal to proton mass, but no charge. He n ATOMIC NUMBER is number of protons & identifies the element ELEMENT SYMBOL

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

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

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

  12. Electromagnetic Spectrumhttp://www.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSpec2.html

  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 science/medicine/reactors.

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

  16. Sources of average radiation dose in the US Consumer Products (2%) Cosmic (5%) Nuclear Power (<0.1%) Human Body (5%) Source: National Council on Radiation Protection and Measurement Report 160 (2006)

  17. 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

  18. 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

  19. PENETRATING ABILITY - + + g b a

  20. SHIELDING Concrete alpha beta gamma Lead Wood Paper

  21. What’s radioactivity?

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

  23. Radioactive atoms emit radiation.

  24. Half Life

  25. Half Life

  26. If I’m exposed to radiation, do I become (more) radioactive?

  27. No!You’ve been irradiated, exposed to radiation.Which is not to be confused with . . .

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

  29. Question... How were radioactive atoms formed?

  30. Answer . . . Supernova Explosion

  31. Question... How do we make a stable atom radioactive?

  32. Answer... • How do we make a stable atom radioactive? • By adding energy to the nucleus • This is done by adding a particle such as a neutron from a reactor or a high energy charged particle from an accelerator such as an electron or proton

  33. 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

  34. 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

  35. 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

  36. How do we protect ourselves? Time Distance Shielding

More Related