Lecture 4 (Chapter 1-2) History and Properties of the X-rays

Question 1

Fluorescence

Answer 1

An emission of light by a substance exposed to various kinds of stimuli

Question 2

Photographic Effect

Answer 2

We can produce the latent image into a visible image

Question 3

Penetrating and Invisible

Answer 3

Can penetrate matter and cannot be seen

Question 4

Ionizing

Answer 4

Ability to alter atoms of matter by removing an electron from an atom. Can have biological effects (cell damage or death)

Question 5

Electrically Neutral

Answer 5

Not affected by magnetic or electric fields

Question 6

Who created the first x-ray in 1895?

Answer 6

Dr. Wilhelm Conrad Roentgen

Question 7

Atoms

Answer 7

smallest particle of an element that retains the properties of the element.

Question 8

The nucleus of the atom contains _____ and ____ subatomic particles

Answer 8

protons, neutrons

Question 9

Radiation

Answer 9

Process by which energy wavelengths in the form of heat, light or rays are sent out of atoms and molecules as they undero internal change

Question 10

X-rays are produced…?

Answer 10

produced when fast moving electrons experience sudden change in direction and/or speed

Begin at Cathode&raquo_space; Anode&raquo_space;

Question 11

Anode

Answer 11

A metal target

Question 12

_____% of energy created is lost in the form of heat.

Answer 12

99

Question 13

Cathode

Answer 13

Negative electrode that has a filament coil of tungsten wire and mounted in a focusing cup made of molybdenum.

Question 14

Thermionic emission

Answer 14

The boiling off of electrons (then ‘hang out’ in a cloud around the filament)

Question 15

Label tubehead (p15)

Answer 15

Cathode=purple C-shape

Anode= green made of tungsten (embedded with copper)

Question 16

Which metals used in conjunction with the anode?

Answer 16

made up tungsten and embedded in copper

Question 17

When x-rays come from anode and leave and exit the tubehead, they pass through _____.

Answer 17

Aluminum disks

Question 18

X-rays with _______ wavelengths are best to get a good image. They will have a higher _______.

Answer 18

shorter; frequency

Question 19

Frequency

Answer 19

Refers to the # of wavelengths that pass a given point in a certain amount of time.

Question 20

Wavelength

Answer 20

Defined as the distance between the crest of one wave and the crest of the next.

Question 21

Filter

Answer 21

Controls the % of x-rays escaping through tubehead; Aluminum disks .5mm thick placed at the opening for x-ray escape; filters low energy, less penetrating, longer wavelength x-rays.

Question 22

By law, >70 kVp eed a minimum of ____ of aluminum filter

Answer 22

2.5mm

Question 23

By law, <70 kVp need a minimum of ____ of aluminum filter

Answer 23

1.5mm

Question 24

Tube Head Housing

Answer 24

Glass envelope surrounding a vacuum; outer housing is metal (decrease leakage)

Question 25

Oil

Answer 25

Between glass envelope and metal; helps absorb heat from x-ray production

Question 26

Collimator

Answer 26

Helps limit patient exposure; Restricts the size and shape of beam; fits directly over the opening of the metal housing, where the x-rays exit.

Question 27

Two types of collimators (can be round or rectangular)

Answer 27

Primary and secondary

Question 28

The primary collimator is made up of a _______ with a small opening

Answer 28

lead

Question 29

Beam size at the patient's face can be no larger than _____.

Answer 29

2.75 inches

Question 30

Secondary collimator is made up of a _____ lined cylinder and directs the beam to the desired area. (Restricts radiation even more)

Answer 30

lead

Question 31

Rectangular collimation exposes approx. ____ less of a patient's face per film.

Answer 31

60%-70%

Question 32

Activation Switch

Answer 32

Preset; maintains function only with continuous pressure.

Question 33

X-rays travel in two forms. They travel in _____ and ____radiation.

Answer 33

wavelength (what we use in clinic); particulate

Question 34

Particulate radiation

Answer 34

Beta particles, Cathode rays, Alpha particles

Question 35

X-ray photon

Answer 35

An x-ray as a bundle of energy

Question 36

Wave radiation

Answer 36

A grouping or form of traveling radiation. Without mass, travel in oscillating electric and magnetic fields. Termed "electromagnetic radiation"

Question 37

Electromagnetic radiation

Answer 37

A type of wave radiation

Question 38

Rank where x-rays fall on the wavelength spectrum from high frequency (short wavelengths) to low frequency.

Answer 38

gamma rays > X-rays > UV > Visible light > Infrared > Microwave > Radio.

Question 39

It takes ____ energy to knock an electron that is close to the nucleus compared to an electron farther away from the nucleus.

Answer 39

more

Question 40

Two types of wave radiation

Answer 40

Bremsstrahlung and Characteristic

Question 41

Bremsstrahlung Production occurs...

Answer 41

as the electron approaches the tungsten target at the anode, the (-) charged electron approachese a (+) charged nucleus. The electron gets deflected from its path and loses kinetic energy.

Question 42

Bremsstrahlung Production- the deflected electron loses _____ energy. (Brems = braking; NO COLLISION) It goes near nucleus but there is no collision

Answer 42

kinetic

Question 43

Characteristic Radiation Production (DOES HAVE COLLISION) It collides with inner shell electron

Answer 43

Incoming electron has high energy. It's strong enough to whack electron from the inner orbital shell ---- so the (e) is displaced. vacancy in the shell is filled by an (e) from an outer shell and so on….. The x-ray energy produced is characteristic to the energy the (e) had when it was in it’s shell

Question 44

______ radiation comprises ~80% of Diagnostic radiation

Answer 44

Bremsstrahlung radiation

Question 45

______radiation comprises ~20% of Diagnostic radiation

Answer 45

Characteristic radiation

Question 46

Characteristic Radiation Production (DOES HAVE COLLISION) It collides with inner shell electron

Answer 46

Incoming electron has high energy. It's strong enough to whack electron from the inner orbital shell ---- so the (e) is displaced. vacancy in the shell is filled by an (e) from an outer shell and so on…. The “energy” left over from the electron falling into the next shell is emitted as the radiation.

Question 47

______radiation comprises ~20% of Diagnostic radiation

Answer 47

Characteristic radiation

Question 48

Velocity = _____

Answer 48

speed

Question 49

Wavelength is measured in _____ / _____

Answer 49

nanometers; meters

Question 50

Ionization - causes a (-) charged electron and a (+) charged atom to form an ______. Atoms losing electrons are called + ions

Answer 50

ion pair

Question 51

Atoms losing electrons are called _____

Answer 51

(+) ions

Question 52

In ionization, the (+) ions usually return to a ______ state.

Answer 52

stable

Question 53

Step Down Transformer (operates 1st)

Answer 53

warms filament, < the voltage between 3-5 volts; controls the number of (e) being produced

Question 54

Kilovolt (kV)

Answer 54

measure of electrical potential-is equal to 1000 volts

Question 55

Kilovolt peak (kvp)

Answer 55

measure of maximum electrical potential in kv across an x-ray tube

Question 56

Two types of currents and what each does

Answer 56

Alternating current-flow of (e) in 2 directions; Direct current- flow of (e) in one direction

Question 57

Step Up Transformer (operates 2nd)

Answer 57

> the potential of the line current; steps up 220 volts to several thousand volts or kiloolts; steps up usually to 50-100 kv

Question 58

1 kilovolt = _______

Answer 58

1000 volts

Question 59

The kvP adjusts the _____ of the beam for better/worse images

Answer 59

quality

Question 60

Milliampere (mA)

Answer 60

Determines the # of electrons available; measures the current; usually 10-15 mA; usually linked and inversely related with time

Question 61

Milliampere (mA) = _______ampre

Answer 61

1/1000 ampre

Question 62

Thermionic emission

Answer 62

electrons are boiled off...

Question 63

The more mA, the more thermionic emission, the more free electrons, the more # x-rays; Basically it is related to ________

Answer 63

Quantity

Question 64

mA boils off or excites the (e) and results in more ______

Answer 64

quantity

Question 65

kvP controls the force of these (e) bombarding the target; results in ________of the image.

Answer 65

quality

Question 66

The process of dental x-ray production (8 steps)

Answer 66

1. Electricity from the wall outlet supplies the power to generate x-rays. When x-ray machine turned on, current enters the control panel and travels to tubehead through the wires in the extension arm. 2.