28.4

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28.4

  1. 1. 28.4 Radiation in Your Life
  2. 2. Ionizing Radiation <ul><li>Radiation with enough energy to knock electrons off atoms and produce ions </li></ul><ul><li>X-rays and radiation emitted by radioisotopes are ionizing radiation </li></ul><ul><li>Not detectable by senses </li></ul><ul><li>Geiger counter detects this type of radiation </li></ul>
  3. 3. Geiger counter <ul><li>Used to detect beta radiation </li></ul><ul><li>Radiation enters gas filled tube and creates ions which conduct electricity </li></ul><ul><li>Bursts of current creates audible clicks or starts electronic counter </li></ul>
  4. 5. Scintillation counter <ul><li>Device with a surface coated with phosphor </li></ul><ul><li>Ionizing radiation causes the phosphor to “flash” when it hits it </li></ul><ul><li>Number of flashes is detected electronically </li></ul><ul><li>TV screens use ZnS as the phosphor and electrons are shot at the screen . The scintillations produce a pattern which is the picture we see </li></ul>
  5. 6. Film Badges <ul><li>Several layers of photographic film covered with black, lightproof paper </li></ul><ul><li>Badges are worn by people who work near radiation sources and are developed at specific intervals </li></ul><ul><li>Used to detect how much radiation a person is exposed to </li></ul>
  6. 7. Radiation Uses <ul><li>Used to detect trace amount of elements by neutron activation </li></ul><ul><li>Neutron activation can be used in forensics- to detect art forgeries, and analyze gunpowder </li></ul><ul><li>Radioactive isotopes can be used to trace where elements go- as in chemical reactions </li></ul><ul><li>Radioactive tracers can trace where substances travel </li></ul>
  7. 8. Radiation Uses <ul><li>Radioisotopes can help diagnose disease- </li></ul><ul><li>I-131 helps diagnose thyroid problems; technetium-99 diagnoses brain tumors and liver problems; P-32 used for skin cancer </li></ul><ul><li>Radiation is used to treat cancer; Co-60 and Cs-137 ; often gamma sources are used- c ancers are more susceptible to high energy radiation </li></ul>
  8. 9. Radiation Uses <ul><li>Salts of radiactive isotopes can be sealed in gold tubes and directly implanted in tumors- emit beta or gamma </li></ul>

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