Card Set Information

2012-11-09 08:17:58

Show Answers:

  1. What is radiation with suffiecient enough energy to seperate an electron from an atom?
    Ionizing radiation
  2. Alpha particles consist of ___ and ____ and are therfore _____
    • 2 protons
    • 2 neutrons
    • helium nuclei
  3. What consists of 2 protons and 2 neutrons and are therefore thought to be helium nuclei
    Alpha particles
  4. What are emitted from unstable heavy nuclei such as radium or radon during the decay process
    Alpha Particles
  5. Alpha particles are emitted from ___ such as ____ or_____ during the decay process
    • unstable heavy nuclei
    • radium
    • radon
  6. Why can alpha particles only travel a short distance?
    • Because of their charge and heavy mass
    • (most can be stopped by a piece of paper)
  7. Alpha particles produce intense ionization and are therefore
    high linear energy transfer (LET) radiation
  8. Because of their charge and heavy mass ___ can travel only short distances, but they produce intense ionization and are high linear energy transfer (LET) radiations
    alpha particles
  9. What are extremely hazardous if ingested or inhaled bu are less danagerous if externally exposed
    Alpha particles
  10. Where are the below found?
    Alpha Particles
    Beta Particles
    Gammy rays
    • In the nucleus
    • only the xrays are found on the electron shells
  11. Where are xrays found?
    electron shells
  12. What are electrons emitted by the nucleus
    beta particles
  13. What is a negatively charged beta particle
  14. What is a positron
    postively charged beta particle
  15. Which beta particle is not stable and only exists for very short periods
  16. Whenever beta particles are emitted, they are accompanied bu a small massless chargeless particle known as
  17. Both types, positive and negative beta particles have the same rest mass as an electron and are usually emitted from the nucleus with high
  18. If metals are used for shielding what can result?
    bremsstrahlung radiation
  19. The probability of bremsstrahlung xray production is ____ to the square of the atomic number of the absorber and ____ to the square of the mass of the incident particle.
    • directly proportional
    • inversely proportional
  20. The probability of bremsstrahlung xray production is directly proportional to the square of the ______of the absorber and inversely proportional to the square of the _____of the incident particle.
    • atomic number
    • mass
  21. What is the bremsstrahlung radaition much more likely to occur with?
    • beta particles
    • rather than alpha
  22. xrays and gamma rays are both forms of
    electromagnetic radiation (photons)
  23. Photons have ___mass and ____ charge
    • no
    • no
  24. What are extranuclear and result from rearrangements within the electron shells or from bremsstrahlung radiation
  25. What is the only difference between xrays and gamma rays
    their origin
  26. What are the most common types of ionizing radiation used in radation therapy
    • xrays
    • gamma rays
    • electrons
  27. What % of radiation exposure of the US comes from natural background sources
  28. Where does most of our radiation exposure come from
  29. what % of radiation exposure is man made
  30. Natural background radation comes from what 3 sources?
    • cosmic rays
    • terrestrial
    • internal deposits of radionuclides
  31. Although the earth's atmosphere acts as a shield from cosmic rays, the primary cosmic rays interact with molecules in the atmosphere to create other reactive agents known as
    secondary particles
  32. Where is cosmic ray radiation exposure higher?
    at the polar regions rather than the equator
  33. Latitude, solar cycles and other factors may account for a variation of 10% exposure. The intensity varies even more with ____
    increasing elevation
  34. Between the Rockys in CO and the swamps of Gainsville, FL, who gets the most cosmic ray radiation?
    Rockys due to higher elevation
  35. Presence of small amts of long lived isotopes of uranium, thorium, and radium is
    source of terrestrial radiation
  36. Who estimated that radon exposure is the 2nd leading cause of lung ca in the US?
    • EPA
    • enviromental protection agency
  37. The EPA estimates that ____ exposure is the 2nd leading cause of lung cancer in the US
  38. Which exposure results from the radioactive materials that are normally present in our bodies
    Internal exposure
  39. What is defined as the amt of ionization prodced by photons in air per unit mass of air
  40. The traditional unit of exposure is
    the Roentgen
  41. What is defined as the energy absorbed per unit mass of any material
    absorbed dose
  42. The SI unit is the ____, which is defined as 1 joule of energy absorbed per kg of absorbing material
    • gray (GY)
    • 1 GY=100cGy=100rad
  43. What takes into acct the fact that different types of radiation produce different amts of biologic damage
    Dose equivalent
  44. Alpha particles and neutrons are high LET and therefore have a greater ____ than xrays
    biologic effect
  45. What is the traditional unit of exposure
    1 Roentgen
  46. What is the traditional unit for absorbed dose
    • 100 rad
    • 1 rad
  47. What is the traditional unit for dose equivalent
    100 rem
  48. What is the traditional unit for activity
    1 Ci
  49. What takes into acct the effect of irradiation of only part of the body or the effect of non uniform irradiation of the body
    Effective dose equivalent
  50. What is the rate at which a radioactive isotope undergoes nuclear decay
  51. The Si unit of activity is the
    becquerel (bq)
  52. What are 2 kinds of gas-filled detectors used to detect when radaition is present?
    ionization chamber and geiger-Muller detector
  53. The ____, consists of 2 electrodes within a gas filled chamber, an applied voltage across the electrodes and electronics and a meter to amplify and measure the electrical signal.
    ionization chamber
  54. When ionization chambers are properly calibrated, their accuracy approaches ____ which makes them suitable for measurement of the radiation ouput of therapy equipement
  55. What is the form of ionization chamber that is used for personnel monitoring?
    pocket dosimeter
  56. Are ionization chambers sesitive? What are they suitable or not suitable for?
    They are not sensitive, so they are are not suitable for the detection of very low levels of radiation or radiation contamination
  57. Because of their sensitivity ____ are best for finding contamination and other low levels of radiation
    GM detectors
  58. Because of their small size, ____ are widely used to measure radiation. These materials give off light when heated.
    thermoluminescent dosimeters TLD
  59. The atomic # of LiF (lithium fluoride) is close to that of ____, and since it does, it is therefore useful as a patient or phantom dosimeter.
  60. If proper care if taken, doses of radiation can be measured with an accuracy of approx ____
  61. After development, xray film exposed to radiation turns ____
  62. The amt of blackness from xray that was exposed to radiation is called ____ and this is related to the amt of radiation received by the film
    optical density
  63. A typical ____ has a slot in which the film may be placed and several thin metal filters that surround portions of the film.
    film badge
  64. The filters from a film badge allow discrimination between different types of radiation. ____ will not penetrate any of the filters but can reach the film in the area where no filters are
    low energy radiation
  65. the primary task of ____ is to analyze the existing data related to radiation exposure and to assess the radiobiologic risks with those exposures
    advisory agency (set the laws)
  66. which agency can develop dose recommendations for dose limits
    advisory agency
  67. The recommendations of this agency may be acted on by Congress or state govt and made into a law
    advisory agency
  68. Name some of the advisory agencies?
    • NCRP-National Council on Radiation Protection and Measurement
    • ICRP- International Commission on Radiation Protection
    • UNSCEAR- United Nations Scientific Committee on the Effects of Atomic Radiation
    • NAS-BEIR- National Academy of Sciences Advisory Committee on the Biological Effects of Ionizing Radiation
  69. The role of this agency is to license users of radioactive materials and radiation-producing equipment, inspect users, and enforce the appropriate laws
    Regulatory Agency
  70. What is one of the leading federal regulatory agency that oversees the use of isotopes produced in nuclear reactors
    • NRC
    • Nuclear Regulatory Commission
  71. The isotopes are commonly used in nuclear medicine depts and as sources for teletherapy (external beam radiation) and brachytherapy. many states have entered into licensing, inspection, and enforcement agreements and are called the agreement states with the
    • NRC
    • Nuclear Regulatory Commission
  72. Give an example of a Regulatory Agency
    • NRC
    • Nuclear Regulatory Commission
  73. Transportation of radioactive material is primarily the concern of
    • DOT- Department of Transportation
    • NRC
  74. The use of machines that produce ionizing radiation, such as xray units and linear accelerators fall under the jurisdiction of
    FDA-Food and Drug Administration
  75. A single whole body dose of _____ is lethal for 50% of the exposed population within 30 days
    • 4.5 GY (450 rads)
    • LD 50/30
  76. Even at levels below the lethal dose, there are significant long-term effects related to exposure to radiation, which 2 categories do these fall in
    • nonstochastic
    • stochastic
  77. _____are those for which a threshold exists and for which the severity of the effect increases with dose.
    nonstochastic effect
  78. What are examples of a nonstochastic effect
    • erythema
    • epilation
    • infertility
    • cataract
  79. ______-are those that have no threshold and for which the probability of occurrence is a function of dose
    stochastic effect
  80. What are examples of the stochastic effect
    • cancer induction
    • genetic effects
    • embryologic
    • teratogenic effects