Exam 1 Flashcards
T/F: Tungsten is used in both the anode and the cathode
True
What are some of the reasons for the use of tungsten in the design of the x-ray tube?
-High atomic number
-Good thermal conductivity
Which of the following help to increase heat capacity of an x-ray tube?
-small actual focal spot
-rotating anode
-large actual focal spot
-small the target angle
-rotating anode
-large actual focal spot
Flow of electrons
actual focal spot
contains the target
anode
flow of photons
effective focal spot
equal intensity in all directions
isotropically
concept that although x-ray photons exist as waves, they exhibit properties of particles
wave particle duality
consists of protons and neutrons
nucleus
distance between the peaks of waves
wavelength
energy that passes from one location to another
radiation
smallest amount of any type of electromagnetic radiation
photon
a neutral atom that gains or loses an electron
ion
building blocks of all matter
atoms
circle the nucleus in orbits called shells
electrons
electromagnetic radiation produced in the nucleus of radioactive atoms
gamma rays
electromagnetic radiation that is able to remove an electron from an atom
ionizing radiation
equals the number of protons in the nucleus; determines the chemical element
atomic number
force that holds electrons in orbit around the nucleus
binding energy
inner most electron shell
K-shell
number of protons plus number of neutrons; represented by the letter A
atomic mass
number of wavelengths passing a given point per unit time
frequency
a single unit of electromagnetic radiation
photon
distance from one peak to another peak
wavelength
A constant value for all electromagnetic radiation
velocity
number of valleys that pass per second
frequency
X-ray’s behave like particles and move as photons. This is known as the:
wave-particle duality
Electrons carry a negative charge and repel one another. They form a cloud around the filament called the:
space charge
X-rays with greater energy have a shorter ______ and are more penetrating.
wavelength
which wave characteristic refers to the height of a wave
amplitude
which term is used to denote the decreased x-ray intensity at the anode end of the x-ray tube?
Heel effect
which term defines the emission of x-rays with equal intensity in all directions?
isotropically
Which of the following on the electromagnetic spectrum have the ability to ionize matter?
(1) Infrared
(2) Radiofrequencies
(3) X-rays
(4) Gamma rays
3 and 4
what describes an atom that has lost one or more of its electrons?
ion
which of the following are considered to be basic properties of x-rays?
1. highly penetrating; invisible
2. has no mass
3. travels at the speed of sound
4. does not has the ability to interact with an atom
1 and 2
which is part of the cathode?
-Stator
-Target
-Filament
-Window
Filament
Which end of the electromagnetic spectrum is more likely to exhibit more of the characteristics of waves?
Low end
what is the velocity of electromagnetic radiation?
speed of light
what is the maximum number of electrons that can occupy the P shell?
72
What is the force that keep electrons in orbit?
Binding energy
What are the two principal classes of ionizing radiation?
electromagnetic and particulate
Are wavelengths inversely or directly proportional to frequency?
inversely
Is wavelength a characteristic of waves or particles?
Waves
Tungsten is the principle material used in the formation of the
-target of a rotating anode
-target of a stationary anode
-x-ray tube filament
-all of the above
all of the above
the negative side of an x-ray tube is commonly called the:
filament/cathode
The heating of the filament in a x-ray tube results in the liberation of electrons by a process termed:
thermionic emission
the purpose of the glass enclosure around the x-ray tube:
maintains a vacuum
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 _________ is the portion of the x-ray tube that contains the filament.
cathode
surrounding the x-ray tube and lined with lead is the:
tube housing
narrowing the thermionic cloud as it is driven toward the anode is the purpose of the:
focusing cup
in a sine wave, the distance from one peak to another is called the:
wavelength
If a wavelength increases, what happens to its frequency?
it decreases
If an atom has more negative charges than positive charges it is said to be a:
negative ion
If an atom had six protons and five electrons, what would its net charge be?
Positive
Free electrons for x-ray production come from the:
filament
Electromagnetic radiation varies in terms of its:
(1) Wavelength
(2) Frequency
(3) Velocity (speed)
1 and 2
Electromagnetic energy includes what types of disturbances in space?
(1) Electric
(2) Magnetic
(3) Mechanical
1 and 2
All of the following are true about the electron except:
-It has one unit of negative charge.
-It is free to travel from one atoms outermost shell to another.
-It is fixed inside the atoms nucleus unable to move.
-It exists as the smallest unit of charge.
It is fixed inside the atoms nucleus unable to move.
the electrons that are traveling from the cathode to the target are called:
projectile/incident electrons
An X-ray tube __________ releases electrons when it is heated. When the current through the __________ is sufficiently high, the outer-shell electrons of the __________ atoms are “boiled off” and ejected from the __________. This is also known as thermionic emission.
Filament
Because of the angled anode target, the radiation intensity is greater on the cathode side of the x-ray field than the anode side. What is this called?
Anode heel affect
what focuses the flow of electrons from the Cathode to the Anode target?
focusing cup
Why is the glass enclosure made of Pyrex glass?
to withstand high temperatures
What are x-rays called that escape through the protective housing?
Leakage radiation
