XRAY EMISSION

Spectrum

Graphic representation of the

range over which a quantity

extends

Discrete spectrum

It contains only specific values

Continuous spectrum

It contains all possible values

X-ray emission spectrum

It can be graphed as the number of X-rays for each increment of energy in keV

Characteristic X-ray spectrum

A plot of the frequency with which characteristic x-rays are emitted as a function of energy

Characteristic X-ray

Have precisely fixed or discrete energies and form discrete emission spectrum

Bremsstrahlung xray spectrum

Extends from 0 to maximum projectile electron energy

Bremsstrahlung X-ray spectrum

Greatest number of X-rays emitted (⅓ of the maximum energy)

kVp operation

Maximum energy of a bremsstrahlung X-ray is equal to <>

X-ray quantity

The more values in the curve the higher the

Higher the effective energy is

The farther to the right the higher the

X-ray quality

Expressed by the half value layer

Half valve layer

Thickness of absorbing material necessary to reduce the x-ray intensity to half of its original value

Half value layer

Best method for specifying x-ray quantity

Tube current

is a factor that affect the xray emission spectra in which a change in mA results in the change in amplitude and the position of the x-ray emission spectrum

Tube voltage

is a factor that affect the xray emission spectra in which a a change in kVp affects both the amplitude and the position of the x-ray emission spectrum

Position of the discrete X-ray emission

tube voltage has no effect on the <>

15%

an increase of % in kVp is equal to doubling the mAs

Filtration

also known as beam hardening

Filtration

increases the average energy

Characteristic spectrum

what spectrum is not affected by the added filtration

Characteristic spectrum and maximum energy of x-ray emission

<> and <> is not affected by the added filtration

0.5 mm Al

equivalent of inherent filtration

1mm Al [port of X-ray tube] 1 mm Al [ collimator]

equivalent of added filtration

2.5 mm Al

equivalent of total filtration

Compensating filter

is a material inserted between the xray source and patient to shape the intensity of the xray beam

Compensating filter

is designed to make the remnant beam more uniform in intensity

Increase, increase

a/an (increase / decrease) in atomic number (increase/decrease) the efficiency of xray production and the energy of characteristics and bremsstrahlung x-rays

Half wave rectified

block one-half of the alternating current (AC) power supply, allowing only the positive half-cycle to pass to the X-ray tube

Full Wave Rectified

Both the positive and negative are converted into a more consistent direct current (DC) for producing X-rays

Three phase, six pulse

Uses 3 sets of alternating waveforms produce a more stable and efficient high voltage for the X-ray tube

Three phase, 12 pulse

produces a smoother and more constant x-ray beam with a lower voltage ripple (around 4%) compared to six-pulse systems (14%)

High frequency

Used to convert the standard alternating current waveform into a much higher frequency reducing and providing nearly a constant voltage to an x-ray tube.