Ch 7 X- ray Production Flashcards
2 types of x-rays:
characteristic and bremsstrahlung
kinetic energy is:
the energy of motion
all electrons have the same ____ and _____, therefore their KE is increased by ____
mass and velocity, raising the kVp
as electron KE is increased both the ____ and _____ of the beam are increased
both the intensity (quantity) and energy (quality) of the beam are increased
the distance b/w the filament and x-ray tube is only”
1 cm
x-ray tube current is aka:
projectile electrons
when projectile electrons hit the atoms of the target they:
transfer their KE
projectile electrons interact with ______ or ______ of the target atoms resulting in:
orbital electrons or nuclear field of the target atoms resulting in the conversion of KE to thermal energy (heat) or electromagnetic radiation (x-rays)
the 99% heat is due to:
projectile electrons interacting with outer shell electrons but not ionizing, so they are constantly excited (heated)
production of heat is directly related to:
the increasing x-ray tube current
heat production also in directly related to:
increasing kVp
characteristic radiation is when:
projectile electrons interact with an inner shell electron of the target rather than an outer shell electron
the interaction is violent enough to:
ionize the target atom through total removal of an inner shell electron
*characteristic x-rays are emitted when:
an outer shell electron fills an inner shell void
the transition of an outer shell electron to an inner shell is accompanied by:
the emission of an x-ray
the x-ray emitted has the energy equal to:
the difference of the binding energy of the electrons involved
K-rays result from:
electron transitions into the K shell
*only the _____ x-rays of _____ are useful for imaging
K-characteristic x-rays of tungsten
*this type of x-radiation is called characteristic because:
it is characteristic of the target element
bremsstrahlung radiation is when:
a projectile electron loses its KE due to its interaction with the nuclear field of the target atom
the lost KE is turned into:
electromagnetic energy
a projectile electron that completely avoids the orbital electrons as it passes through a target atom:
may become sufficiently close to the nucleus to be influenced by its electric field
because the electron is (-) and the nucleus is (+):
there is electrostatic force of attraction b/w them
as the projectile electron passes by the nucleus it ____; the lost KE reappears as____
is slowed down and changes its course, leaving with reduced KE in a different direction; the lost KE reappears as an x-ray
Bremsstrahlung x-rays are produced when:
a projectile electron si slowed by the nuclear field of a target atom nucleus
“Bremsstrahlung” means
“slowed down radiation”
*In the diagnostic range most x-rays are: Characteristic or Bremsstrahlung?
Bremsstrahlung
Bremsstrahlung x-rays can be produced at _____ projectile electron energy
any
K-characteristic x-rays require an x-ray tube potential of ____
at least 69 kVp
*a discrete spectrum contains:
only specific values
*a continuous spectrum contains:
all possible values
the discrete characteristic x-rays are characteristic of:
the differences b/w electron binding energies in a particular element
fixed (or discrete) energies form:
a discrete emission spectrum
Bremsstrahlung x-rays energies range from:
the peak electron energy to 0
a range of energies forms:
a continuous emission spectrum
*maximum x-ray energy is associated with:
minimum x-ray wavelength
maximum x-ray energy is numerically equal to the:
kVp
in the electron emission graph the farther right a spectrum is:
the higher the effective energy of the beam (quality) (keV)
the larger the area under the curve:
the higher the intensity (quantity) (number of x-rays)
*a change in mA or mAs results in a proportional change in:
the amplitude of the x-ray emission spectrum at all energies
*a change in kVp has ___ effect on the _____ emission spectrum
no, discrete
*15% increase in kVp is equal to ______ but it does not _____
equal to doubling the mAs but does not double the intensity
adding filtration to the beam reduces _____ while increasing _____
reduces intensity while increasing the average energy
filtration is sometimes called _____ because ____
hardening, because of the increase in average energy
the atomic number (Z) of the target affects both:
the number (quantity) and effective energy (quality)
as the (Z) increases so does:
the efficiency of the production of Bremsstrahlung radiation
half-wave and full-wave rectified waveforms are the same except for:
the frequency of the pulse repetition
the difference b/w 3 phase 6 pulse and 3 phase 12 pulse is:
the reduced ripple of the 12 pulse
*because of the reduced ripple in 3 phase and high frequency, it is equal to:
a 12% increase in kVp or a doubling of mAs in a single phase
increase in current (mAs) results in:
increased quantity, no change in quality
increase in voltage (kVp):
increase in both quality and quantity
added filtration results in:
decrease in quantity, increase in quality
increase in target atomic # (Z) results in:
increase in both quality and quantity
increase in voltage ripple results in:
decrease in both quality and quantity
peak x _____ = average keV
peak x .707 = average keV
average keV x ___ = peak
average keV x 1.41 = peak
discrete will only change if:
you raise the kVp higher than the characteristic kVp
any shift of the peak left or right means:
a change in energy
change in mAs:
change in quantity
change in kVp:
change in quantity and quality
when you add filtration the peak:
drops lower and to the right
Compton radiation affects:
outer shell electrons
photoelectric radiation affects:
inner shell electrons
pair production requires ___ MeV
.02 MeV
photodisintigration requires ___ MeV
2 MeV
classic=
soft tissue
increase in kVp = _____ in amplitude and a peak movement to the _____
increase in amplitude and a peak movement to the right
decrease in kVp = ____ in amplitude and a peak movement to the _____
decrease in amplitude and a peak movement to the left
in a graph with multiple peaks, the Bremsstrahlung peak is located (right or left):
to the left (lowest energy)
high frequency’s peak will be:
the highest and most to the right
single phase’s peak will be:
the lowest and most to the left
minimum wavelength = _______
1.24/keV (Angstroms)
Angstrom = ____
10^-10 m
the ____ the IR size…..
the ____ the SID…..
the ____ the angle….
the more likely to have heel effect
the larger the IR size
the larger the SID
the smaller the angle
