XrAY WEEK 3

Question 1

ionization

Answer 1

removal of an e-

Question 2

radiodensity is sometimes used to describe

Answer 2

radioqacity

Question 3

ionizing radiation may either be ___ & _______

Answer 3

electromagnetic or particulate in nature

Question 4

examples of ionizing particle radiation includes

Answer 4

alpha and beta particles

Question 5

the two types of e-magnetic energy that has enough energy to ionize matter? and where do they originate from?

Answer 5

Gamma- originates from the nucleus X-rays - originates from the e- shells

Question 6

radioactive atoms have unstable what?

Answer 6

nucleus

Question 7

unstable nuclei of atoms may eject what two things?

Answer 7

particles and/or energy to attain more stable configuraiton

Question 8

alpha particle is made up of

Answer 8

2 protons and 2 neutrons

Question 9

beta particles are made up of

Answer 9

electron like particle much less mass than alpha and travels further than the alpha

Question 10

half life is the time necessary for what?

Answer 10

time necessary for rate of atomic disintegrations to decrease by one-half

Question 11

Photon

Answer 11

= smallest unit of e-magnetic radiation

Question 12

smallest unit of elecrtomagnetic radiation

Answer 12

photon

Question 13

photon travels at the speed of what

Answer 13

light

Question 14

do photons have a charge?

does a photon have a mass?

Answer 14

no

Question 15

photons have what 2 components

Answer 15

electric and magnetic fields *

Question 16

Important characteristics of electromagnetic waves

Answer 16

Velocity (for our discussion of x-rays fixed, ie., always speed of light = c ) Frequency (nu or f ) Wavelength (lambda λ)

Question 17

velocity formula

Answer 17

frequency * wavelength

Question 18

there is an _____ relationship of frequency and wavelength due to a fixed ____

Answer 18

inverse , velocity

Question 19

photon energy is ____ related to ___ velocity

Answer 19

1.directly 2.fixed

Question 20

frequency relationship to the energy of a photon is

Answer 20

a direct relationship ~

as F increases = Photon energy increases

Question 21

as frequency increases what happens to the energy

Answer 21

it increases

Question 22

inverse square law

Answer 22

The intensity (amount of energy per unit area) of radiation changes inversely according to the square of the distance from the source

Question 23

how to solve for the inverse square law

Answer 23

Express the change in distance as either a fraction or a multiple (eg, “on-third the distance” or “three times as far”) Take the INVERSE of the fraction or multiple (eg, inverse of 1/3 = 3 or inverse of 3 = 1/3) SQUARE it to find the change in intensity (eg, 2x2 = 4 or 1/3 x 1/3 = 1/9)

Question 24

x-rays represent a range of _____ near the highest level of electromagnetic spectrum

Answer 24

frequencies

Question 25

all x rays _____ have the same amount of frequency or wavelength meaning they do not have the same? a. do not, b. do,

Answer 25

a. DO NOT | 2. Energy

Question 26

X-rays behave more like particles than

Answer 26

“waves”

Question 27

Electromagnetic radiation with wavelengths longer than that of the x-ray spectrum behave more

Answer 27

as waves

Question 28

X-ray characteristics

Answer 28

Cannot be focused or reflected in the fashion of visible light Have the ability to penetrate matter Can cause some substances to fluoresce (emit visible light) Travel in in a straight line thru space Can cause ionization (ejection of electron from atom) Can expose photographic film Potentially harmful to living organisms- much more on this later Are more likely to interact with matter that has size similar to x-ray wavelength

Question 29

Radiolucent =

Answer 29

material thru which x-rays pass more easily Analogous term to visible light concept of “translucent” material

Question 30

Radiopaque =

Answer 30

material thru which x-rays do not pass easily Analogous term to visible light concept of “opaque” material

Question 31

The radiopacity of objects is related to their physical _____?

Answer 31

density (more dense = more radiopaque)

Question 32

The 5 are, in order of increasing radiopacity, (OR less radiolucent)

Answer 32

Air Fat Water Calcium (bone) Metal

Question 33

organs and tissues are more like what density?

Answer 33

water

Question 34

x-rays turn the film what color?

Answer 34

black

Question 35

radioqaque will appear more what on xray?

Answer 35

white due to increase of density

Question 36

if you have a decrease of radiopaque it will appear what? (decrease of density)

Answer 36

darker

Question 37

beam quality | refers to

Answer 37

photon energy

Question 38

beam quantity | refers to

Answer 38

number of photons

Question 39

hard vs soft x-rays

Answer 39

“Hard” x-rays have higher energy (less wavelength and higher frequency) “Soft” x-rays have lower energy (greater wavelength and lower frequency)

Question 40

X-ray originates from what?

Answer 40

electron cloud

Question 41

X-ray photon energy is typically expressed in units called electron _________ or, because diagnostic x-rays are produced by using high voltage potentials, the unit _______

Answer 41

1. volts (eV) 2. kiloelectron volts (keV) is used

Question 42

x-rays, gamma rays (and higher frequency ultraviolet radiation) are the only______ forms of electromagnetic radiation

Answer 42

ionizing

Question 43

AMP =

Answer 43

unit of electrical current Describes how many electrons are moving

Question 44

Current =

Answer 44

flow of electrons

Question 45

VOLT =

Answer 45

unit of electrical potential describes how much force are electrons moving with

Question 46

3 basic factors of x-ray machine exposure settings are:

Answer 46

AMPERAGE, VOLTAGE and TIME

Question 47

Coulomb © =

Answer 47

Coulomb is the fundamental unit of electrical charge

Question 48

Ampere (A) =

Answer 48

unit of electrical current A flow of electrons is called “current”. Measures the # of electrons flowing in a circuit Equal to one coulomb of charge flowing through a conductor each second- it is therefore a measure of the rate that electrical charge is being transferred.

Question 49

AC is known as

Answer 49

alternating current : moving in direct current : electron motion is n one direction only a backward and forward motion

Question 50

DC is known as

Answer 50

direct current : electron motion is n one direction only

Question 51

voltage ripple | term to describe

Answer 51

the fluctuation in electrical potential that occurs in alternating current * not desirable for produciton of x-ray

Question 52

alternating current has what kind of graph pattern (trig)

Answer 52

sinusoidal

Question 53

sinusoidal and pattern shows a pattern with voltage and amperage levels falling to?

Answer 53

zero 3X during each cycle

Question 54

DC may have a ripple voltage? T/F

Answer 54

T: More like a pulse

Question 55

rectification

Answer 55

changing of an AC to a DC

Question 56

Full wave rectification

Answer 56

inverts one half of a single phase current Electron flow again in one direction, but gap reduced There is still a brief period during which voltage and current values fall to zero = large voltage ripple

Question 57

3 phase current reduces voltage ripple by

Answer 57

superimposing 3 single phase waveforms, slightly out of time with one another.

Question 58

3 phase current can be rectified to further minimize

Answer 58

voltage ripple

Question 59

high frequency voltage

Answer 59

most current technology. | less of a voltage ripple much more efficient way to take x-ray

Question 60

as wavelength increases what happens to the photon energy

Answer 60

it will decrease because they have an inverse relationship

Question 61

1/2 rectification

Answer 61

eliminates 1/2 of single phase waveform ~ resulting in increase of gap and voltage variation

Question 62

full wave rectification vs 1/2 wave rectification | full wave:

Answer 62

inverts 1/2 of single phase current | 1/2 wave rectification: eliminates 1/2 of single phase wave form