Chapter 12: The X-Ray Tube Flashcards
T/F: The x-ray tube is housed in lead as a radiation protection measurement.
True
surrounds the x-ray tube and is lined with lead
tube housing
the opening where the X-rays exit the tube; thinner area of the glass envelope
tube port/tube window
the source of the x-rays
x-ray tube
x-rays that are not part of the primary beam
leakage radiation
receives the energy of the x-ray beam (after traveling through the patient) and forms the image of the body part
image receptor
All are part of the cathode except the:
-Focusing cup
-Filament
-Rotor
-Filament current
Rotor
As the target angle of the anode decreases, what happens to the effective focal spot size?
it decreases
From what metal are the filament wires in radiographic tubes made?
Tungsten
In a modern rotating anode, the rotor motion is accomplished by the use of a/an:
induction motor
In a modern x-ray tube, the positively-charged electrode that serves as the target for the electron stream is the
Anode
In the x-ray tube electrons flow to the anode from what component?
Filament
when X-rays are emitted they travel in equal intensity in all directions.
Isotropically
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
high melting point
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?
No, it is not ok to use them to move the equipment.
The anode angle is used to reduce the effective focal spot size in relation to the actual focal spot size. This is called the:
line focus principle
The cloud of electrons surrounding a heated filament is called
space charge
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
smaller than the actual focal spot
The heel effect occurs because of:
x-ray absorption in the anode
The outer-shell electrons of the filament atoms are boiled off and ejected from the filament. This is known as ____________.
thermionic emission
The positive side of the x-ray tube is the_______, and the negative side is the _________.
anode; cathode
The primary purpose of the glass envelope/enclosure of an x-ray tube is to:
provide a vacuum
The protective housing of an x-ray tube is designed to:
reduce hazard of leakage radiation
The reduction of focal spot size can be accomplished by:
using a smaller filament
The thin, flattened surface of the x-ray tube envelope which allows for the minimum absorption of x-rays is termed the:
x-ray window
The two filaments of the cathode are referred to as:
large and small
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
1, 2 and 3
Which is part of the cathode?
-Filament
-Stator
-Target
-Window
Filament
Which part of the x-ray tube undergoes thermionic emission?
Filament
Which portion of the x-ray tube is the negatively charged metal shroud that surrounds the filament?
focusing cup
