1. What is the primary decay mode of Co-60?

• Gamma emission

• Beta -

• Electron capture

• Alpha decay

1. What is the energy of a photon with a frequency of 600MHz?

• 0.5 x 10-6 MeV

• 2.5 x 10-12 MeV

• 3.7 x 10-9 MeV

• 5.11 x 10-1 MeV

A 6MeV photon back-scatters off of an electron. What fraction of its original energy does the photon retain after this scattering event?

• • 19%

• • 11%

• • 1%

• • • 4%

Which element has the highest Compton mass attenuation coefficient?

• Lead

• Boron

• Hydroge

• Oxygen

What is the minimum energy at which pair production is the most probable photon interaction in water?

• 30MeV

• 100MeV

• 1.022MeV

• 18MeV

Which of the following types of radiation carry the same charge? (Select all that apply)

• Beta+ - rays and Alpha - rays

• X-rays and Gamma-rays

• Beta+ - rays and Protons

• Beta- - rays and Delta - rays

 A 3MeV photon undergoes a 30 degree Compton scattering event with an electron in air. How many ion pair will the electron produce?

• 39000

• 7801000

• 9421000

• 487000

The probability of pair production is proportional to

• Zln(E)

• (Z/E)^3

• EZ

• 1/Z

A 10MeV proton traveling through water looses energy at a known rate. What energy would an electron need to have in order to loose energy at the same rate in water as the proton?

• 5.4keV

• 511keV

• 0.054MeV

• 0.511keV

Bremsstrahlung results in the emission of what type of radiation?

• Alpha-rays

• Gamma-rays

• X-rays

• Beta-rays