rad physics ch.7,8,9

Question 1

why is the X-ray tube enclosed in a Pb housing?

Answer 1

reduce leakage radiation

Question 2

leakage radiation should not exceed?

Answer 2

1 mGya/hr at a distance of one meter

Question 3

is KE proportional to mass

Answer 3

yes

Question 4

what is the relation of KE and the square of the V

Answer 4

Directly proportional

Question 5

what is the relationship of KE and V

Answer 5

not proportional

Question 6

how do we relate KE in X ray?

Answer 6

when electrons go from cathode to anode

Question 7

how do you find V in the X ray tube?(Formula)

Answer 7

v^2=2KE/m

Question 8

Infrared radiation

Answer 8

electrons are raised to a higher energy level and when they return to normal state. outer shell interaction but no ionization

Question 9

Bremsstrahlung radiation

Answer 9

when the projectile electron brakes (curves) around the nucleus

Question 10

when will more Bremsstrahlung release more radiation

Answer 10

when the projectile electron brakes for a longer period of time resulting in a short wavelength with high Bremsstrahlung radiation

Question 11

at 100 kVp how much bremsstrahlung and characteristic radiation produced

Answer 11

85% will be bremsstrahlung and 15% will be characteristic

Question 12

at what kVp will the target not produce characteristic ionizing radiation

Answer 12

69kVp

Question 13

the greatest number of x-rays have___ of the maximum energy

Answer 13

1/3

Question 14

what is the maximum energy equal to

Answer 14

kVp

Question 15

what part of the X-ray tube is moelydium

Answer 15

Neck of the anode

Question 16

what is amplitude in the X ray tube?

Answer 16

quantity of X- ray

Question 17

an increase in mAs will do what to X-ray Quality, X-ray quantity ?

Answer 17

none, increase

Question 18

an increase in kVp will do what to X-ray Quality, x-ray quantity?

Answer 18

increase, increase

Question 19

an increase in Distance will do what to X-ray Quality, x-ray quantity?

Answer 19

none, reduce

Question 20

filtration will do what to X-ray Quality, x-ray quantity?

Answer 20

increase, reduce

Question 21

what is Half-value layer (HVL)

Answer 21

reduces the intensity by half

Question 22

what type of beam does the HVL start with ?

Answer 22

heterogenous (high and low energy Beams)

Question 23

after the HVL what type of beam should be left?

Answer 23

Homogenous

Question 24

how much filteraon is in the collimator assembly

Answer 24

1.0 mm Al/eq

Question 25

how much filtration is between the port/housing

Answer 25

1.0-2.0 mm Al/eq

Question 26

what is the required inherent filtration

Answer 26

.5-1 mm Al/eq

Question 27

what is cascading

Answer 27

when the electron hole in the K shell is filled by the L shell

Question 28

does scatter add to patient dose?

Answer 28

yes

Question 29

Compton interaction

Answer 29

incident photon interacts with an outer shell electron and creates an ejection the the electron called the recoil electrons and scattered photon.

Question 30

Compton effect formula

Answer 30

E(incident photon)= E(scattered Photon) +{E(binding energy

Question 31

Photoelectric interaction

Answer 31

electron interacts with an inner shell electron which leads to the incident being absorbed. By-products are photoelectron- ejectedhlectron and characteristic radiation aka florescent radiation

Question 32

names of coherent scattering

Answer 32

classical scattering; Elastic scattering; Unmodifed scattering

Question 33

Quantum Noise

Answer 33

visible as brightness or density fluctuations

Too few X-ray photons= increase quantum noise

Question 34

types of image distortion

Answer 34

size and shape

Question 35

single phase half-wave has how many cycles/sec produced

Answer 35

60 cycles/sec produced

Question 36

single phase full-wave has how many cycles/sec produced

Answer 36

60 cycles/sec produced

Question 37

three-phase, 6 pulsehas how many cycles/sec

Answer 37

60 cycles/ sec produced

Question 38

three-phase, 12 pulse has how many cycles/sec

Answer 38

60 cycles/ sec produced

Question 39

what type if contrast is seen in a photoelectric interaction?

Answer 39

high radiographic contrast; short scale contrast

Question 40

photoelectric interaction formula

Answer 40

PE=1/E^3; PE=Z#^3