Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Dosimetry > Interactions Of Ionizing Radiation > Flashcards

Interactions Of Ionizing Radiation Flashcards

1
Q

characteristic radiation occurs from what effect?

A

from photoelectric effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

in elastic interaction, what happens to E of e-?

A

given to e- in target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

in inelastic interaction, what happens to E of e-?

A

only partially given up to target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Brems aka

A

radiative collision interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what happens to photon in transmission

A
  • photon passes w/no interaction

- no E exchanged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

coherent scatter aka

A

aka classical, unmodified, thompson

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

photoelectric effect has what kind of absorption?

A

true E absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

does photoelectric effect depend on E?

A

yes- as E increases, photoelectric effect decreases (inversely prop)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

auger e-

A

-mono E e- produced by absorption of characteristic xrays by atom & reemission of E in form of orbital e- ejected from atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

photonuclear interaction (photodisintegration) occurs at what E?

A

15MeV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

compton scatter aka

A

modified scatter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

compton depends on

A
  • E of photon- inv prop (Z does NOT affect it)= decr w/incr E
  • e- density- depends on # of e- per gram
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

pair production occurs at what E?

A

higher E; 10 MeV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

pair production depends on

A

Z (dir prop to z^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

linear attenuation coefficient definition

A
  • probability per unit thickness that any one photon will be attenuated
  • fx of photons removed from a beam per cm of absorber
  • fx of photons removed per unit thickness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

linear attenuation coefficient affected by e- density?

A

yes, e- density of absorber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Co-60/1.25 MeV dmax

A

0.5 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

4 MV dmax

A

1 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

6 MV dmax

A

1.5 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

10 MV dmax

A

2.5 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

15 MV dmax

A

3 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

18 MV dmax

A

3.5 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

20 MV dmax

A

3.5 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

25 MV dmax

A

5 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

QF (quality factor) formula

A

dose equiv= absorbed dose * QF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

xray QF

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

gamma QF

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

e- QF

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

thermal n QF

A

5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

alpha particle QF

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

n QF

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

p+ QF

A

10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

R (Roentgen) unit for

A

exposure in air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

absorbed dose measured in

A

rad or Gy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

250keV dmax

A

surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

6MeV dmax

A

1.2 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

9MeV dmax

A

2.0 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

12MeV dmax

A

2.5 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

when streams of fast moving e- interact w/target of anode, 2 types of x-rays generated:

A
  • brems

- characteristic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

max electronic buildup

A

secondary e- are set into motion when high photons strike medium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

characteristic radiation is what kind of interaction?

A

collision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

characteristic radiation has what kind of spectrum?

A

discrete

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

in characteristic radiation e- interacts with ?

A

e- of target

44
Q

characteristic radiation collisions are?

A

excitation or ionization

45
Q

characteristic radiation happens when e- does what?

A

fills vacancy

46
Q

characteristic radiation has no importance in what?

A

MV

47
Q

characteristic radiation can produce ? e-?

A

auger

48
Q

in elastic interaction, what is conserved?

A

momentum & KE?

49
Q

in elastic interaction, what is not lost?

A

E

50
Q

in inelastic interaction, what is conserved?

A

momentum; KE not

51
Q

Brems most created for

A

therapy

52
Q

in Brems, e- attracted to

A

nucleus

53
Q

what happens to e- in Brems?

A

passes near, slows down, and loses KE

54
Q

Brems has what kind of spectrum?

A

continuous

55
Q

in Brems, intensity is proportional to ?

A

beam current

56
Q

in Brems, x-rays emitted what direction?

A

any angle

57
Q

in Brems, photon E is equal to ?

A

E lost by e-

58
Q

in coherent scatter what happens to e-?

A

not enough E to free e- (vibrates) but E absorbed

59
Q

what does coherent scatter produce?

A

very low E photon, scatters

60
Q

photoelectric effect in what E range

A

10-30 kvp

61
Q

in photoelectric effect, photon interacts with?

A

atom & ejects orbital e-

62
Q

in photoelectric effect, what is the KE of photon?

A

initial photon E minus binding E

63
Q

photoelectric effect involves what e-?

A

inner shell

64
Q

in photoelectric effect, what is created?

A

vacancy= characteristic xrays

65
Q

in photoelectric effect if angle is 90 deg, what kind of E?

A

low

66
Q

in photoelectric effect if angle is 10 deg, what kind of E?

A

high

67
Q

is photoelectric effect dependent on Z?

A
  • yes, directly proportional to Z^3 (mass coef dependent)

- Z^4- atomic coef dependent

68
Q

probability of Brems varies with ?

A

Z^2 of target material

69
Q

is photoelectric effect dependent on E?

A

yes

70
Q

photonuclear interaction aka

A

photodisintegration

71
Q

photonuclear interaction (photodisintegration) is an interaction between what?

A

photon & nucleus

72
Q

in photonuclear interaction (photodisintegration), makes nucleus unstable and emits ?

A

neutron (why we shield) & gamma

73
Q

in photonuclear interaction (photodisintegration) what happens to incoming photon?

A

complete absorption

74
Q

Compton scatter E range

A

60kVp-10MeV

75
Q

Compton used in

A

radiation therapy

76
Q

in Compton scatter, photon has how much E?

A

more thank outer shell e-

77
Q

in Compton scatter, incoming photon interacts with?

A

outer shell e- (loosely bound)

78
Q

what is a scattered e- called

A

recoil e-

79
Q

in Compton scatter, E is?

A

both absorbed & scattered

80
Q

pair production can only occur when what happens

A

photon has 1.02 MeV threshold dose

81
Q

in pair production what happens to photon

A

complete absorption

82
Q

in pair production what happens to photon E

A

converted to positron & e- (matter created)

83
Q

in pair production, what happens to positron

A

loses KE & recombines with free e- (annihilation rxn)

84
Q

what is is called when positron combines with free e-

A

annihilation rxn

85
Q

linear attenuation coefficient formula

A

0.693/HVL

86
Q

linear attenuation coefficient unit

A

1/cm or cm^-1

87
Q

linear attenuation coefficient affected by E?

A

yes, increase E, decrease u (inv prop)

88
Q

linear attenuation coefficient affected by Z?

A

yes, increase Z, increase u (dir prop)

89
Q

linear attenuation coefficient is affected by ? of absorber

A

state

90
Q

QF definition

A

-compares biological effectiveness of particulate radiation to std xray rad

91
Q

R (Roentgen) only applies at what E

A

3 MeV

92
Q

R (Roentgen) only applies to what radiation

A

x-ray & gamma

93
Q

R (Roentgen) only happens when?

A

e- equilibrium exists

94
Q

R (Roentgen) SI unit

A

C/kg

95
Q

R (Roentgen) only measures what?

A

products of ionization- not photons

96
Q

R (Roentgen) is NOT

A

E or intensity or absorbed

97
Q

R (Roentgen) is? C/kg

A

2.58 x 10^-4 C/kg

98
Q

1 R air kerma deposits ? of absorbed dose in air

A

0.877 rad

99
Q

F factor is

A

the tissue dependent conversion from kerma to absorbed dose

100
Q

absorbed dose defines

A

quantity

101
Q

absorbed dose applies to

A

all types of radiation & E ranges

102
Q

absorbed dose applies in areas where ?

A

e- equilibrium does NOT exist

103
Q

max electronic buildup depends on

A

photon E & medium composition

104
Q

Dmax is defined as

A

max dose obtained at depth where electron equilibrium reached

105
Q

Binding energy per nucleon is

A

8 MeV per nucleon

106
Q

Most important physical quantities that are conserved in a nuclear reaction are

A
  • charge
  • mass number
  • linear momentum
  • mass-energy

Dosimetry (53 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions