Chapter 08 - X-Ray Production

During x-ray production, almost all of the kinetic energy of the incident electrons is converted to

a. a bremsstrahlung photon.

b. a characteristic x-ray photon.

c. light.

d. heat.

d. heat.

What percentage of target interaction results in the production of x-ray photons?

a. 1 percent

b. 50 percent

c. 99 percent

d. 100 percent

a. 1 percent

The transfer of the incident electrons' kinetic energy to the outer-shell electrons, causing vibration of the outer-shell electron, results in the emission of

a. infrared radiation.

b. ultraviolet radiation.

c. light.

d. electricity.

a. infrared radiation.

The types of target interaction that occur in the production of x-ray photons in the diagnostic range are dependent upon the

a. incident electron kinetic energy.

b. nuclear binding energy.

c. incident electron potential energy.

d. band gap of the valence electrons.

a. incident electron kinetic energy.

The energy of a bremsstrahlung photon is

a. equal to the kinetic energy of the entering electron.

b. equal to the kinetic energy of the exiting electron.

c. the sum of the entering and exiting kinetic energies of the incident electron.

d. the difference between the entering and exiting kinetic energies of the incoming electron.

d. the difference between the entering and exiting kinetic energies of the incoming electron.

Bremsstrahlung interactions may occur only when the incident electron interacts with

a. an inner-shell electron.

b. an outer-shell electron.

c. the force field around the nucleus.

d. the nuclear force within the nucleus.

c. the force field around the nucleus.

Characteristic interactions may occur only when the incident electron interacts with

a. an inner-shell electron.

b. an outer-shell electron.

c. the force field of the nucleus.

d. the band gap of the atom's valence band.

a. an inner-shell electron.

During a characteristic interaction, the kinetic energy of the incident electron must be ____ of the electron it knocks from its orbit.

a. less than that

b. greater than that

c. proportional to that

d. characteristic

b. greater than that

During a characteristic interaction, the dropping of a higher-energy state electron into a lower-energy state "hole" results in the emission of

a. a photon of electromagnetic energy.

b. a high-energy electron.

c. a low-energy electron.

d. thermal energy.

a. a photon of electromagnetic energy.

The energy of a characteristic photon is

a. equal to the binding energy of the entering electron.

b. equal to the binding energy of the exiting electron.

c. the sum of the binding energy of the outer and inner shells between which the electron dropped.

d. the difference between the binding energy of the outer and inner shells between which the electron dropped.

d. the difference between the binding energy of the outer and inner shells between which the electron dropped.

At the end of the characteristic cascade, the ____ shell is missing an electron.

a. innermost

b. K

c. outermost

d. characteristic

c. outermost

The K shell can hold a maximum of ____ electrons.

a. 1

b. 2

c. 6

d. 8

b. 2

If the peak kVp is 110, the average keV energy of the beam would be

a. 12-24 keV.

b. 33-44 keV.

c. 66-77 keV.

d. 110 keV.

b. 33-44 keV.

X-rays are characterized as

a. charged particles.

b. electromagnetic waves of short wavelength.

c. electromagnetic waves with high frequencies.

d. both b and c.

d. both b and c.

The emission spectrum of an x-ray beam from a tungsten anode consists of

a. a characteristic spike at 69 keV.

b. a significant portion due to bremsstrahlung interactions.

c. a mixture of brems and characteristic interactions.

d. all of the above.

d. all of the above.

If uranium were used to produce x-radiation, rather than tungsten,

a. the K-shell binding energy would be greater than with tungsten.

b. the intensity of brems production would be greater.

c. the energy of characteristic photons would be greater than with tungsten.

d. all of the above.

d. all of the above.

Electrons traveling from the cathode filament to the anode are called

a. incident electrons.

b. primary electrons.

c. scatter electrons.

d. secondary electrons.

a. incident electrons.

When comparing the x-ray emission spectrum between beams produced at 70 kVp and 110 kVp,

a. the 110 kVp beam would demonstrate less brems and a higher characteristic spike.

b. the 110 kVp beam would demonstrate more brems and a higher characteristic spike.

c. the 70 kVp beam would demonstrate less brems and a higher characteristic spike.

d. the 70 kVp beam would demonstrate an equal amount of brems and characteristic radiation.

b. the 110 kVp beam would demonstrate more brems and a higher characteristic spike.

For the element molybdenum, the effective energy of characteristic interactions is

a. 9 keV.

b. 18 keV.

c. 42 keV.

d. 69 keV.

b. 18 keV.

When the x-ray emission spectra between single- and three-phase generators are compared,

a. three-phase beams would have a higher average energy.

b. single-phase beams would be more intense.

c. less exposure would be required for the same part thickness, using single phase.

d. the keV of the characteristic spike would be significantly less with the single-phase generator.

a. three-phase beams would have a higher average energy.

Tungsten is the anode material of choice for x-ray production because of its

a. ability to expand with high speed rotation G-forces

b. ability of liberating electrons as secondary x-ray sources

c. creation of off-focal radiation

d. excellent k-edge value for x-ray production

d. excellent k-edge value for x-ray production

Molybdenum is an excellent target material for mammography studies due to its

a. light composite weight during rotation and quite operation.

b. excellent heat tolerance with high kVp exposures used in mammography.

c. k-edge production of characteristic radiation, to match soft tissues of the breast.

d. ability to suppress brems x-ray production and heighten characteristic production..

c. k-edge production of characteristic radiation, to match soft tissues of the breast.