* RADT 334 - FINAL (Study Stack) *

effect of an increase in kVp on compton scatter

decrease

energy range for photodisintegration

10 MeV

energy range for pair production

1.02 MeV

energy range for coherent scatter

< 10 keV

interactions with matter occurring in the diagnostic energy range

Compton scatter and photoelectric

The x-ray intensity is lower on the anode side of the tube because of the _____.

anode heel effect

as the angle of a target gets bigger, the effective focal spot will get ______

bigger

the effective focal spot is ____ than the actual focal spot

smaller

what makes a good contrast agent?

high mass density, high atomic number

the difference in x-ray interaction by various body tissue

differential absorption

differential absorption is dependent upon this

kV, Z number, mass density

used to make a uniform density on a radiograph for a non uniform part thickness

compensating filter

What happens to the x-ray beam when you increase the kV by 15%

you get the effect of the mAs doubling (increase in density)

circuits on the operating console are _____ voltage

low

how does AEC work?

exposure ends once a certain radiation level reaches the image receptor

Voltage ripple of high-frequency generator

Voltage ripple of single-phase generator

100%

Voltage ripple of three-phase, six-pulse generator

14%

Voltage ripple of three-phase, twelve-pulse generator

4%

If you have greater voltage ripple, you will have a ____ in image quality

decrease

If you have greater voltage ripple, you will have a ____ in image quantity

decrease

where radiation is made in the x-ray tube

anode

where electrons strike the target to make x-rays

focal spot

where electrons are boiled off

filament

what keeps the electrons together in a cloud near the filament

focusing cup

the kinetic energy of electrons is converted into mostly _____ in the x-ray tube

heat

_______ of the kinetic energy of electrons is converted into x-rays

two interactions that occur at the anode to produce radiation

characteristic and bremsstrahlung

five interactions in matter

coherent scatter, compton scatter, photoelectric absorption, pair production, photodisintegration

interaction at the anode where electron interacts with inner shell electron

characteristic

interaction at the anode where electron interacts with nuclear field and slows

bremsstrahlung

discrete portion of x-ray emission spectrum is from _____ radiation

characteristic

continuous x-ray emission spectrum is from _____ radiation

bremsstrahlung

to change the discrete x-ray emission spectrum, one would need to change this

atomic number of target material

electrical charge of an atom

0

electrical charge of an electron

negative

electrical charge of a proton

positive

electrical charge of a neutron

0

name the orbital shells from innermost to the fourth outer shell

K, L, M, N, O . . .

smallest part of an element

atom

smallest part of electromagnetic energy

photon

as the distance between the source and image increases, x-ray quantity at the image _____

decreases

as the wavelength of a photon increases, the energy of the photon ______

decreases

as the frequency of a photon increases, the energy of the photon _____

increases

like charges

repel

unlike charges

attract

unit of electric potential

volt

unit of electric charge

coloumb

unit of power

Watt

unit of electric current

amp

unit of electric resistance

ohm

rate of doing work

power

faraday proved what?

a magnetic field in motion could produce an electric current

Oersted proved what?

a current produces a magnetic field

an electric current is induced in a circuit if some part of that circuit is in a changing magnetic field defines ________

electromagnetic induction

removal of an electron from an atom

ionization

electron removed from atom and atom it originated from

ion pair

acronym for as low as reasonably achievable

ALARA

basic quanities in mechanical physics

mass, length, time

mass x distance

force

KE of random motion of molecules

heat

electrostatic force is directly proportional to the product of the electrostatic charges and inversely proportional to the square of the distance between them

coulomb's law

electric charge distribution is ______ in a diffuse nonconductor (electrified object - like a cloud)

uniform

electric charge distribution is ______________ in a conductor (like a wire)

concentrated along the sharpest curvature

xrays are produced in this part of the atom

orbital shells

gamma rays are produced in this part of the atom

nucleus

unit for patient dose

rad, Gray

unit for occupational dose

rem, Sievert

unit for radiation in air

roentgen, Coulomb per kilogram

unit for radioactivity

curie, Becquerel

1 R =

1 rad or 1 rem

SI unit of occupational dose

Sievert

SI unit of patient dose

Gray

Si unit of radiation in air

gray in air, Air kerma, or Coulomb per kilogram

SI unit of radioactivity

bequerel

what type of transformer has a single winding

autotransformer

the kV meter is on the ____ side of the x-ray circuit

primary

the mA meter is on the ____ side of the x-ray circuit

secondary

as voltage is _____, amperage decreases

increased

the focal spot selector is located in this portion of the x-ray circuit

filament circuit

a step up transformer is used in what part of the circuit?

between low and high voltage/between primary and secondary sides

a step down transformer is used in what part of the circuit?

filament circuit

the step up transformer changes _____ into _____

volts; kilovolts

emission spectrum: increasing mAs

increase amplitude

emission spectrum: increasing kV

increase amplitude and shift to right

emission specturm: increase filtration

decrease amplitude and shift to right

emission spectrum: increase atomic number of target material

increase amplitude and shift to right

When distance is doubled, intensity of x-ray beam is ______ by _______.

reduced; factor of four

controlling factors of beam quality

kV, filtration

controlling factors of beam quantity

mAs, kv, filtration - mAs being the main controlling factor

beam quantity is directly proportional to

mAs

HVL is a measurement of

beam quality

no ionization takes place in which of the radiation interactions with matter

coherent

No more electrons can be boiled off of the filament because of this phenomenon

space charge

What is a radiographic rating chart used for?

maximum exposure times

ways to increase efficiency of x-ray production

increase kV, increase atomic number of target material, use equipment with least voltage ripple

as the peak of the x-ray emission spectrum moves to the left, what is affected? How?

beam quality, decreases

electrons boiled off of the filament and being attracted to tungsten plating the inside of the x-ray tube

tube arcing

which way do electrons flow in the x-ray tube?

cathode to anode

which side of the beam is "hotter" or more intense?

cathode