Radiography Chapter 2

Front 1

Describe Ion:

Back 1

An atom that gains or loses an electron and becomes electrically unbalanced

Front 2

Are some atoms more likely than others to become ionized?

Back 2

Yes

Front 3

Definition of Ion Pair:

Back 3

the ionized atom and the ejected electron (both are free to react with other atoms and will attempt this to reach electrical stability)

Front 4

Do ion pairs elicit chemical changes in matter?

Back 4

Yes

Front 5

T/F: X-rays can eject electrons from the atom forming an ion pair

Back 5

True

Front 6

Definition of Ionization:

Back 6

Production of ions (the process of converting atoms into ions)

Front 7

What kind of force binds electrons to the nucleus?

Back 7

Electrostatic

Front 8

Radioactivity:

Back 8

The process by which certain unstable atoms or elements undergo spontaneous disintegration, or decay, in an effort to attain a more balanced nuclear state

Front 9

T/F: A substance is considered radioactive if it gives off energy in the form of particles or rays as a result of the disintegration of atomic nuclei

Back 9

True

Front 10

Radiation:

Back 10

propagation of energy in the form of waves or particles

Front 11

Ionizing radiation:

Back 11

Radiation that is capable of producing ions

Front 12

Particulate Radiation:

Back 12

when tiny particles of matter (mass) travel in straight lines at high speeds, transmitting kinetic energy

Front 13

How many types of particulate radiation are there?

Back 13

4

Front 14

What are the 4 types of particulate radiation?

Back 14

1) Electrons

2) Alpha particles

3) Protons

4) Neutrons

Front 15

Classifications of electrons in particulate radiation

Back 15

1) Beta particles

2) Cathode rays

Front 16

Beta particles

Back 16

fast moving electrons emitted from the nucleus of radioactive atoms

Front 17

Cathode rays

Back 17

streams of high-speed electrons that originate in an x-ray tube

Front 18

T/F: Both beta particles and cathode rays originate from the same origin

Back 18

False

Beta particles=nucleus of radioactive atoms

Cathode rays=x-ray tubes

Front 19

Alpha particles

Back 19

emitted from the nuclei of heavy metals, exist as 2 protons and 2 neutrons

they have a +2 charge

Front 20

Protons

Back 20

accelerated particles

specifically H+ (ion) with a mass of 1 and a charge of +1

Front 21

Neutrons

Back 21

accelerated particles with a mass of 1 and no electrical charge

Front 22

Electromagnetic Radiation:

Back 22

propagation of wave-like energy (without mass) through space or matter

Front 23

Does electromagnetic radiation contain electric and magnetic fields?

Back 23

Yes

Front 24

List some examples of electromagnetic radiation

Back 24

cosmic rays, gamma rays, x-rays, UV rays, visible light, infrared light, radar waves, microwaves, and radio waves

Front 25

Electromagnetic spectrum:

Back 25

continuum of electromagnetic waves

Front 26

T/F: EM radiations moves through space as both a particle and a wave

Back 26

True

Front 27

Wave concept

Back 27

explains why an x-ray may be reflected, refracted, diffracted and polarized

focuses on the properties of velocity, wavelength, and frequency

Front 28

Particle concept

Back 28

used to describe the interactions between radiation and matter (usually the negative effects)

characterizes EM radiations as discrete bundles of energy called photons or quanta

Front 29

Photons

Back 29

bundles of energy with no mass that travel as waves at the speed of light, in a straight line

Front 30

Name the 3 properties of the wave concept

Back 30

1) Velocity

2) Wavelength

3) Frequency

Front 31

Velocity

Back 31

speed of the wave

Front 32

Wavelength

Back 32

the distance between the crest of one wave and the crest of the next

determines the energy and penetrating power of the radiation

Front 33

T/F: the shorter the wavelength, the higher the energy and more penetrating power it has

Back 33

True

Front 34

Frequency

Back 34

number of wavelengths that pass a given point in a certain amount of time

Front 35

Which of the 3 properties of the wave concept are inversely related?

Back 35

Frequency and Wavelength

Front 36

T/F: The greater the frequency of the wavelength (shorter), the greater the energy of the photon

Back 36

True

Front 37

X-radiation:

Back 37

high energy, ionizing, electromagnetic radiation

Front 38

List properties of x-rays

Back 38

1) Invisible, no mass, no charge

2) Travel at the speed of light, in short wavelengths (high frequency) in a straight line and can be deflected or scattered

3) Can't be focused to a point, they diverge just like visible light

4) Can pass through liquids, solids and gases

5) Can cause certain substances to fluoresce or emit radiation in longer wavelengths (visible or UV light)

6) Can cause biologic changes in living cells (cause ionization)

Front 39

List the 3 component parts of an x-ray machine

Back 39

1) Control panel

2) Extension arm

3) Tubehead

Front 40

Control panel

Back 40

contains an on/off switch with indication light, exposure button with indicator light, and control devices that regulate the x-ray beam

Front 41

Extension arm

Back 41

suspends the x-ray tubehead and houses the electrical wires and allows for movement and positioning of the tubehead

Front 42

Tubehead

Back 42

tightly sealed, heavy metal housing that contains the x-ray tube which produces x-rays

Front 43

What is the x-ray tube composed of?

Back 43

1) Leaded-glass housing

2) Cathode

3) Anode

Front 44

Cathode:

Back 44

Negative electrode that supplies the electrons necessary to generate x-rays

Consists of:

1) Tungsten wire filament

2) Molybdenum cup

Front 45

Anode:

Back 45

Positive electrode; it will convert electrons into x-ray photons

Consists of:

1) Tungsten target

2) Copper stem

Front 46

*Transformers:

Back 46

a device that is used to either increase or decrease the voltage in an electrical circuit

Front 47

Step-up transformer:

Back 47

used to increase the voltage for the high-voltage circuit

from 110-220 volts to 65,000-100,000

has more wire coils in the secondary coil than in the primary coil

Front 48

Step-down transformer:

Back 48

used to decrease the voltage from the incoming line (110-220 v.) to the 3-5 volts required for the filament circuit

has more wire coils in the primary coil than in the secondary coil

Front 49

Autotransformer:

Back 49

serves as a voltage compensator that corrects for minor fluctuations in the current

Front 50

Production of x-rays

Back 50

X-rays are generated when fast-moving electrons collide with matter

Front 51

How much of the energy is converted to x-rays?

Back 51

1%

Front 52

What does the other 99% produce?

Back 52

Heat

Front 53

*General radiation (Bremsstrahlung)

Back 53

"braking radiation" when high speed electrons suddenly stop when they hit the tungsten target

Front 54

*Approximately what percent of the energy produce x-rays from general radiation?

Back 54

70%

Front 55

*When does general radiation occur?

Back 55

Occurs when an electron hits the nucleus of a tungsten atom or when an electron passes very close to the nucleus

The electron is attracted and slows down, resulting in an x-ray photon of lower energy

Many different energies and wavelengths result

Front 56

Characteristic radiation:

Back 56

when a high speed electron dislodges an inner shell electron from the tungsten atom and causes ionization of that atom

Front 57

What is a characteristic of characteristic radiation?

Back 57

The other orbits will rearrange

Front 58

T/F: Characteristic radiation accounts for a small percentage of x-rays produced

Back 58

True

Front 59

T/F: Characteristic radiation ONLY occurs at 70 kVp and above

Back 59

True

Front 60

*Primary radiation "useful beam":

Back 60

penetrating x-ray beam that is produced at the target of the anode and exits the tubehead

Front 61

*Secondary radiation:

Back 61

x-radiation created when the primary beam interacts with matter (the patient's tissue)

less penetrating

Front 62

*Scatter radiation:

Back 62

form of secondary radiation that is deflected from its path

this is detrimental to both the patient and the radiographer

Front 63

What are the 4 interactions of x-radiation:

Back 63

1) No interaction

2) Absorption

3) Compton scatter

4) Coherent scatter

Front 64

Photoelectric effect falls under what interaction of x-radiation?

Back 64

Absorption

Front 65

*Photoelectric effect:

Back 65

an x-ray photon collides with a tightly bound inner shell electron and gives up all of its energy to eject the electron from the orbit

**accounts for 30% of the interactions of matter with the x-ray beam

Front 66

*Compton scatter:

Back 66

after the x-ray photon collides with a loosely bound outer shell electron it loses part of its energy and continues in a different direction (scatters) at a lower energy level

accounts for most of the scatter radiation (62%)

ionization takes place

Front 67

*Coherent scatter (unmodified scatter):

Back 67

involves a low-energy x-ray photon that has its path altered by matter (the interaction with an outer shell electron)

no change in the atom occurs, no loss of energy, and no ionization occurs

accounts for 8% of the interactions of matter

Front 68

Which interaction has the highest percentage?

Back 68

Compton scatter (62%)

Front 69

Which interaction has the lowest percentage?

Back 69

Coherent scatter (8%)