X-Ray Beam

Question 1

The size of the area on the anode target that is exposed to electrons from the tube current

Answer 1

actual focal spot

Question 2

Filtration that is added to the port of the x-ray tube. Aluminum is the material primarily used for this purpose because it absorbs more low-energy photons while the useful higher-energy photons can exit

Answer 2

Added filtration

Question 3

positively charged electrode

Answer 3

Anode

Question 4

What materials is the anode made of?

Answer 4

Tungsten Z #74
Molybdenum Z#42
Copper Z#24
Graphite

Target is made of Tungsten & Rhenium Z#75

Question 5

Anode Heel Effect

Answer 5

How the x-ray beam has greater intensity (number of x-rays) on the cathode side of the tube but a lower intensity toward the anode side

Question 6

projectile electron completely avoids the orbital electrons of a tungsten atom and travels very close to its nucleus

Answer 6

Bremsstrahlung interactions

Question 7

negatively charged electrode

Answer 7

Cathode

Question 8

projectile electron interacts with an electron from the inner shell (K-shell) of a tungsten atom

Answer 8

Characteristic interactions

Question 9

added to the primary beam to alter its intensity

Answer 9

Compensating filter

Question 10

Examples of compensating filters

Answer 10

trough, wedge, boomerang, Ferlic

Question 11

focal spot size as measured directly under the anode target

Answer 11

effective focal spot

Question 12

coiled tungsten wire, which is the source of electrons during x-ray production

Answer 12

filament

Question 13

Describe the function and purpose of the focusing cup

Answer 13

Made of nickel
surrounds the filament
open at one end to allow electrons to flow freely across the tube from cathode to anode.
negative charge – keeps the cloud of electrons emitted from the filament from spreading apart.

Its purpose is to focus the stream of electrons.

Question 14

amount of filtration that reduces the intensity of the x-ray beam to one-half of its original value

Answer 14

Half-value layer (HVL)

Question 15

amount of heat produced from any given exposure is expressed

Answer 15

Heat Units HU

Question 16

An exposure is made with a three-phase x-ray unit at 800 mA and 80 kVp over 0.5 s. How many heat units are produced from this exposure?

Answer 16

43,200 HU

Question 17

An exposure is made with a high frequency x-ray unit at 400 mA and 75 kVp over 0.05 s. How many heat units are produced from this exposure?

Answer 17

2,100 HU

Question 18

An exposure is made with a single-phase x-ray unit at 300 mA and 73 kVp over 0.03 s. How many heat units are produced from this exposure?

Answer 18

657 HU

Question 19

Describe inherent filtration

Answer 19

filtration that is permanently in the path of the x-ray beam

(1) the envelope of the tube
(2) the oil that surrounds the tube
(3) the window in the tube housing

Question 20

any x-rays, other than the primary beam, that escape the tube housing

Answer 20

Leakage radiation

Question 21

100 mR/hr to escape when measured at a distance of 1 m from the source while the tube operates at maximum output

Answer 21

Maximum allowance of leakage radiation

Question 22

relationship between the actual and the effective focal spots in an x-ray tube

Answer 22

Line focus principle

Question 23

Tube current is the number of electrons flowing per unit time between the cathode and the anode

Answer 23

mA

Question 24

when projectile electrons are reflected and x-rays are produced from outside the focal spot

Answer 24

off focus radiation

Question 25

connected to the target through the anode stem

Answer 25

rotor | causes the target to rapidly rotate during x-ray production

Question 26

electrons liberated from the filament during thermionic emission form a cloud around the filament

Answer 26

space charge

Question 27

tendency of the space charge to prevent more electrons to be boiled off of the filament

Answer 27

space charge effect

Question 28

electric motor that turns the rotor at very high speed

Answer 28

stator

Question 29

part of the anode that is struck by the focused stream of electrons coming from the cathode

Answer 29

Target

Question 30

When a third-grade student was asked to define the term "vacuum" in class she answered...

Answer 30

"A vacuum is an empty region of space where the Pope lives." hahahaha!

Question 31

Are we having fun yet!

Answer 31

Absolutely

Question 32

When the tungsten filament gains enough heat (therm), the outer-shell electrons (ions) of the filament atoms are boiled off, or emitted, from the filament.

Answer 32

Thermionic Emission

Question 33

The speed of the electrons traveling from the cathode to the anode increases as the kilovoltage applied across the x-ray tube increases.

Answer 33

Relationship between kVp and speed of e-

Question 34

voltage waveforms in terms of how much the voltage varies during x-ray production

Answer 34

voltage ripple

Question 35

x-ray beam is polyenergetic (has many energies) and consists of a wide range of energies

Answer 35

x-ray emission spectrum