Radiation Therapy Physics- Mosby Board Review Questions

  1. The half life of Ir 192 is 74 days. The decay constant is:
    In2/74= 0.00094 days-1
  2. What are the differences between an electron and a proton?
    • Electrons are light, negatively charged particles:they can collide and interact with other particles
    • Protons are are heavy, positively charged particles that can only interact with electrons
  3. Types of decay include all of the following EXCEPT:
    2) neutron
    4)internal conversion
  4. During x-ray production, the reslting x-ray bem comes from electrons colliding with the target and causing interactions such as:
    1)characteristic radiation
    2)bremstrahlung radiation
    3)auger electrons
    4) all of the above
    all of the above
  5. The positive side of the x-ray tube is known as the:
    • anode 
    • "A's are positive :) "
  6. A radioactive source has an initial activity of
    60 mCi. It's half life is 8 days. What is the remaining activity after 10 days?
    • 25 mCi
    • A=Ao(.5)t/h
    • A=60(.5)10/8
  7. The average life of a source with a half life of 8 days is:
    • 8 (1.44)=11.5 days
    • T1/2(1.44)
  8. The ratio of x-ray to heat in x-ray production is:
    Variable  depending on the maximum energy of the electrons traversing the tube
  9. The radioactive decay of a isotope is characterized by its:
    decay constant
  10. An elastic collision is one in which:
    the incoming electron gives up all of its energy to the electron it encounters
  11. The energy of an electromagnetic radiation is inversely proportional to its
  12. If a 50 keV electron collides with an inner shell electron with a binding energy of 25 keV, the resulting photoelectron will have an energy of:
    • 25 keV
    • (50-25)
  13. The energy of an electromagnetic radiation is directly proportional to its:
  14. List photon interactions:(5)
    • compton
    • coherent
    • photodisintegration
    • photoelectric
    • pair production
  15. List electron interactions(2):
    • bremmstrahlung
    • characteristic
  16. The decay of Cobalt-60 to stable lead is an example of ____decay.
    beta negative

    (gamma rays and beta negative)
  17. Regarding isotopes, isotopes of an element have the same number of______but a different number of neutrons.
  18. Match the following:
    Isotopes: ___        A. Ir192   Ir192m
    Isobars:  ___         B.  27Fe59  27Fe58
    Isotones: ___        C. 28Ni60  31Ga60
    Isomers: ____        D.  11Na22   10Ne27
    • Isotopes: _B__   (7Fe59  27Fe58)    
    • Isobars:  _C__     ( 28Ni60  31Ga60
    • Isotones: _D__     (1Na22   10Ne27)
    • Isomers: _A___    (Ir192   Ir192m)
  19. Ir192  is an ________.
  20. If the decay constant of a particularisotope is 45 sec-1, the half life is:
    • 0.015 sec
    • In2/decay constant = half-life
  21. If the half-life of Co-60 is 5.26 years, what is the average life?
    1.44(5.26)=7.57 years
Card Set
Radiation Therapy Physics- Mosby Board Review Questions
Radiation Therapy Physics- Mosby Board Review Questions