Physics Chapter 7

Front 1

the principle parts of an xray imaging system designed to provide a large number of electrons with high kinetic energy focused towards a small spot on the anode

Back 1

operating console, high voltage generator, xray tube

Front 2

energy of motion

Back 2

kinetic energy

Front 3

if electrons have the same mass, how do you increase electrons kinetic energy

Back 3

raising kVp

Front 4

as election kinetic energy is increased, both the intensity (____) and the energy (____) of the xray beam are increased

Back 4

quantity, quality

Front 5

at 100 mA , _____ electrons travel from the cathode to the anode of the xray tube every second

Back 5

6x10 to the 17th

Front 6

keV

Back 6

kiloelectron volt

Front 7

at 70 kVp, each electron arrives at the target with a maximum kinetic energy of

Back 7

70 keV

Front 8

the distance between the filament and xray tube target is only ___cm

Back 8

one

Front 9

electrons traveling from cathode to anode constitute the xray tube current and are sometimes called

Back 9

projectile electrons

Front 10

what happens when projectile electrons hit the heavy metal atoms of the xray tube target

Back 10

they transfer their kinetic energy to the target atoms

Front 11

these interactions result in the conversion of electron kinetic energy in _____ energy (heat) and electromagnetic energy in the form of ______ (also heat) and xrays

Back 11

thermal, infrared radiation

Front 12

most of the kinetic energy of projectile electrons is converted into

Back 12

heat

Front 13

projectile electrons do not have enough energy to ionize these outer shell electrons, there they simply

Back 13

excite, or raise to a higher energy level

Front 14

outer shell electrons immediately drop back to their normal state and emit

Back 14

infrared radiation

Front 15

how much of the projectile's kinetic energy is converted into heat

Back 15

99%

Front 16

approximately how much of the projectiles electrons kinetic energy is used for the production of x radiation

Back 16

1%

Front 17

the production of heat in the anode increases directly with increasing

Back 17

xray tube current

Front 18

at 60 kVp only ____ of electron kinetic energy is converted to xrays

Back 18

.5%

Front 19

at 100 kVp approximately ___ is converted to xray

Back 19

1%

Front 20

at 20 MV ____ is converted to xray

Back 20

70%

Front 21

if a projectile electron interacts with an inner shell election of the target rather than with am outer shell electron, this is a

Back 21

characteristic xray

Front 22

emitted when an outer shell electron fills an inner shell void

Back 22

characteristic xray

Front 23

the transition of an orbital election from an outer shell to an inner shell is accompanied by the emission of

Back 23

xray

Front 24

electrons in outer shell have to give up energy to get to a lower this is an example of what type of energy

Back 24

inherent energy

Front 25

how can you calculate the energy given up from each shell

Back 25

by its binding energy

Front 26

when a K shell electron is ionized it can be filled with an electron from any of the outer shells, these xrays are called

Back 26

K xrays

Front 27

projectile electrons pass by the nucleus, it is slowed down and changes it's course, leaving it with less kinetic energy in a different direction, the loss of kinetic energy reappears as

Back 27

xrays

Front 28

produced when a projectile electron is slowed by the nuclear field of a target atoms nucleus

Back 28

Bremsstrahlung xray

Front 29

what does Bremsstrahlung mean

Back 29

slowed down radiation

Front 30

can be considered radiation that results from the breaking of projectile electrons by the nucleus

Back 30

Bremsstrahlung xray

Front 31

in the diagnostic range most xrays are

Back 31

Bremsstrahlung xrays

Front 32

what does a discrete spectrum only contain

Back 32

specific values

Front 33

a continuous spectrum contains

Back 33

all possible values

Front 34

what xrays are the only characteristic xrays of tungsten with sufficient energy to be of value in diagnostic radiology

Back 34

K xrays

Front 35

what xrays have a range of energies and form a continuous emission spectrum

Back 35

Bremsstrahlung

Front 36

t or f is the shape of the bremsstrahlung xray spectrum is the same for all xray imaging systems

Back 36

true

Front 37

the maximum energy (keV) of a bremsstrahlung xray is numerically equal to the ___ operation

Back 37

kVp

Front 38

xray energy is inversely proportional to it's wavelength. As xray wavelength increases, xray energy ____

Back 38

decreases

Front 39

the farther to the right a spectrum is the higher the effective energy or ___ of the xray beam

Back 39

quality

Front 40

the larger the area under the curve the higher is the xray intensity or ___

Back 40

quantity

Front 41

if one changes the current from 200 to 400 mA while all other conditions remain constant, twice as many electrons will flow from the cathode to the anode and the mAs will be

Back 41

doubled

Front 42

in other words the xray emission spectrum will be changed in ___ but not ___

Back 42

amplitude, shape

Front 43

when kVp is increased the relative distribution of emitted xray energy shifts to the ____ to a higher average xray energy

Back 43

right

Front 44

a change in kVp affects both the ____ and the ____of the xray emission spectrum

Back 44

amplitude, position

Front 45

adding filtration to the useful beam reduces xray beam ___ while increasing the average _____

Back 45

intensity, energy

Front 46

the result of added filtration is an increase in the average ____ of the xray beam with an accompanying reduction in xray _____

Back 46

energy, quantity

Front 47

adding filtration is sometimes called _____ the xray beam because of the relative increase in average energy

Back 47

hardening

Front 48

what spectrum is not affected, nor the maximum energy of xray emission when filtration is added

Back 48

characteristic

Front 49

the atomic number of the target affects both the number (____) and the effective energy (____) of xray

Back 49

quantity, quality

Front 50

as the atomic number of the target material increases the efficiency of the production of bremsstrahlung radiation ____, and high energy xrays ___ in number to a greater extent than low energy xrays

Back 50

increase, increase

Front 51

increasing rather atomic number enhances the efficiency of xray production and the energy of ____ and ______ xrays

Back 51

characteristic, bremsstrahlung

Front 52

a high voltage ripple is

Back 52

bad

Front 53

an increase in current (mAs) results in

Back 53

an increase in quantity, no change in quality

Front 54

an increase in voltage (kVp) results in

Back 54

an increase in quantity and quality

Front 55

an increase in added filtration results in

Back 55

a decrease in quantity and an increase in quality

Front 56

an increase in target atomic number (Z) results in

Back 56

an increase in quantity and quality

Front 57

an increase in voltage ripple results in

Back 57

a decrease in quantity and quality