6 Flashcards
process of adding together the number of x-rays emitted at each energy over the entire spectrum,
integration
the farther to the right a spectrum is
the higher the effective energy or quality of the x-ray beam
the larger the area under the curve
the higher is the x-ray intensity or quantity
energy
quality
intensity
quantity
when mA is double
mAs is doubled
how to get mAs
mA x s
effect of mA and mAs
Change in mA or mAs results in a PROPORTIONAL change in the amplitude of the x-ray emission spectrum at all energies
effect of kVp
As the kVp is raised, x-ray quantity increases with the square of the factor by which kVp was increased
effect of kVp
change in kVp affects both amplitude and position of x-ray emission spectrum
rule of thumb
“A 15% increase in kVp is equivalent to doubling the mAs.”
to increase the intensity, increase kVp up to
40%
effect of added filtration
reduces x-ray beam intensity while increasing the average energy
adding filtration also called as
hardening the xray beam
result of adding filtration
increase in the energy of x-ray beam and reduction in x-ray quantity
effect of target material
affects both quantity and quality of x-rays
Increasing target atomic number enhances the
efficiency of x-ray production and
the energy of characteristic and bremsstrahlung x-rays.
five voltage waveforms
Half-wave–rectified
Full-wave–rectified
Three-phase/six-pulse
Three-phase/ 12-pulse
High-frequency waveforms
produce the lowest voltage ripple of all high-voltage
generators
High-frequency generators
voltage across the x-ray tube is zero
t=0
the voltage across the x-ray tube has increased from 0 to approximately 60,000 V
t = 1 ms
the tube voltage has increased to approximately 80,000 V
t = 2 ms
the maximum tube voltage is obtained
t = 4 ms
more intense x-ray emission than single-phase
operation
voltage waveforms of three-phase or high frequency operation
number of x-rays emitted at each instant through a cycle is not proportional to the voltage
(no answer)
number of x-rays emitted at each instant through a cycle is not proportional to the voltage.
reduced in ripple
operation with three-phase power is approximately 12% increase in kVp
