Chapter 12: The X-Ray Tube

Question 1

T/F: The x-ray tube is housed in lead as a radiation protection measurement.

Answer 1

True

Question 2

surrounds the x-ray tube and is lined with lead

Answer 2

tube housing

Question 3

the opening where the X-rays exit the tube; thinner area of the glass envelope

Answer 3

tube port/tube window

Question 4

the source of the x-rays

Answer 4

x-ray tube

Question 5

x-rays that are not part of the primary beam

Answer 5

leakage radiation

Question 6

receives the energy of the x-ray beam (after traveling through the patient) and forms the image of the body part

Answer 6

image receptor

Question 7

All are part of the cathode except the:
-Focusing cup
-Filament
-Rotor
-Filament current

Answer 7

Rotor

Question 8

As the target angle of the anode decreases, what happens to the effective focal spot size?

Answer 8

it decreases

Question 9

From what metal are the filament wires in radiographic tubes made?

Answer 9

Tungsten

Question 10

In a modern rotating anode, the rotor motion is accomplished by the use of a/an:

Answer 10

induction motor

Question 11

In a modern x-ray tube, the positively-charged electrode that serves as the target for the electron stream is the

Answer 11

Anode

Question 12

In the x-ray tube electrons flow to the anode from what component?

Answer 12

Filament

Question 13

when X-rays are emitted they travel in equal intensity in all directions.

Answer 13

Isotropically

Question 14

Necessary properties of x-ray target material include which of the following?
-high melting point
-high rotation speed
-low coefficient of friction
-high electrical resistance

Answer 14

high melting point

Question 15

Should the high voltage/high tension cables extending from the ceiling to the X-ray tube assembly ever be used to move the X-ray equipment?

Answer 15

No, it is not ok to use them to move the equipment.

Question 16

The anode angle is used to reduce the effective focal spot size in relation to the actual focal spot size. This is called the:

Answer 16

line focus principle

Question 17

The cloud of electrons surrounding a heated filament is called

Answer 17

space charge

Question 18

The effective focal spot is:
-smaller than the actual focal spot
-larger than the actual focal spot
-the same size as the actual focal spot

Answer 18

smaller than the actual focal spot

Question 19

The heel effect occurs because of:

Answer 19

x-ray absorption in the anode

Question 20

The outer-shell electrons of the filament atoms are boiled off and ejected from the filament. This is known as ____________.

Answer 20

thermionic emission

Question 21

The positive side of the x-ray tube is the_______, and the negative side is the _________.

Answer 21

anode; cathode

Question 22

The primary purpose of the glass envelope/enclosure of an x-ray tube is to:

Answer 22

provide a vacuum

Question 23

The protective housing of an x-ray tube is designed to:

Answer 23

reduce hazard of leakage radiation

Question 24

The reduction of focal spot size can be accomplished by:

Answer 24

using a smaller filament

Question 25

The thin, flattened surface of the x-ray tube envelope which allows for the minimum absorption of x-rays is termed the:

Answer 25

x-ray window

Question 26

The two filaments of the cathode are referred to as:

Answer 26

large and small

Question 27

Which are characteristics of tungsten that make it the material of choice for x-ray tube targets?
(1) High atomic number
(2) Good thermal conductivity
(3) High melting point

Answer 27

1, 2 and 3

Question 28

Which is part of the cathode?
-Filament
-Stator
-Target
-Window

Answer 28

Filament

Question 29

Which part of the x-ray tube undergoes thermionic emission?

Answer 29

Filament

Question 30

Which portion of the x-ray tube is the negatively charged metal shroud that surrounds the filament?

Answer 30

focusing cup