Physics Chapter 6 Test

Question 1

Know the 2 ways filament electrons interact with target atoms to produce x-rays?

Answer 1

Characteristic interaction and bremsstrahlung interactions

Question 2

How do characteristic photons get their name?

Answer 2

Their energy is “characteristic” or dependent on the difference in binding energy between the shells involved

Question 3

Know why medical imaging generally focuses on the K shell

Answer 3

It has the highest energy and the most useful for imaging purposes

Question 4

Know how you remove orbital electrons during characteristic interactions

Answer 4

the filament electron must have kinetic energy equal to or greater than the binding energy of the electron with which it interacts

Question 5

Describe what happens during a bremsstrahlung interaction

Answer 5

A filament electron is attracted to the nucleus causing it to slow down and change direction. The energy loss is emitted as a bremsstrahlung photon

Question 6

Know what the strength of the interaction depends on with a brems interaction

Answer 6

How close the filament electron passes to the nucleus

Question 7

Know how to find the energy of a brems photon

Answer 7

Subtracting the energy that filament electron leaves the atom with from the energy it had upon entering

Question 8

Know the 4 technical factors that affect beam quantity

Answer 8

mAs
KVP
Distance
Filtration

Question 9

Know what you should always associate beam quantity with

Answer 9

Radiation dose

Question 10

Know what is directionally proportional with beam quantity?

Answer 10

mAs

Question 11

Know what is considered the primary controlling factor for beam quantity

Answer 11

mAs

Question 12

Know how beam quantity varies

Answer 12

Square of the ratio of the change in kVp

Question 13

Know what a 15% increase in kVp is equivalent to

Answer 13

Doubling the mAs

Question 14

Be able to work a problem using the Inverse Square Law

Answer 14

I1/I2= D2^2/D1^2

Question 15

Know how filtration affects beam quantity

Answer 15

Decreases

Question 16

Know what it looks like on an image when photons reach the IR

Answer 16

dark shades of the image

Question 17

Know what image looks like when no photons reach the IR

Answer 17

light or clear areas of the image

Question 18

Know what affects beam quality

Answer 18

kVp and filtration

Question 19

Know what the purpose filtration serves

Answer 19

To remove the lower-energy photons, making the average energy (quality) higher

Question 20

Know how beam quality is measured

Answer 20

half value layer

Question 21

Know how to find half value layer

Answer 21

First measuring the intensity of the beam with a radiation detector, then placing aluminum filters of known thickness between the tube and detector until the intensity reading is reduced to half the original value

Question 22

Know the normal HVL range for general diagnostic beams

Answer 22

3-5 mmAC

Question 23

Know how the characteristic photons are named (2)

Answer 23

for the shell being filled

Question 24

Know why a brems photons energy depends on the strength of attraction

Answer 24

Because brems photons are the result of the filament electrons attraction to the nucleus

Question 25

Know what the most common range of energy of a brems photon is

Answer 25

just above zero to max kVp

Question 26

Know what shape a brems photon graph represents

Answer 26

bell shape

Question 27

Know what the left and right side of the curve represents for a brems photon graph

Answer 27

left just above zero, right-touches the x axis at the kVp selected

Question 28

know what the peak of a brems photon graph represents

Answer 28

one third of the kVp selected

Question 29

On the emission spectrum changes in the following indicate:

a. y axis
b. X axis

Answer 29

Y Axis- changes in quantity

X axis- changes in quality

Question 30

Know what the five factors are that change the appearance of the xray emission spectrum

Answer 30

mA, kVp, tube filtration, generator type, and target material

Question 31

Know what changes in mA affect (include discrete line)

Answer 31

Affect beam quantity but has no affect on quality and does not change the position of the discrete line

Question 32

Know what changes in kVp affect ( include the discrete line)

Answer 32

Affect beam quality and quantity but does not change the position of the discrete line

Question 33

Know what tube filtration affects when all other factors remain the same

Answer 33

Decrease in Quantity

Increase in quality

Question 34

Know what the changes in generator type can affect

Answer 34

Change the xray production efficiency

Question 35

Know why high frequency generator units are used over single phase units

Answer 35

more efficient in producing xray than single phase units

Question 36

Know what happens when a generator operates more efficiently

Answer 36

More filament electrons have the energy to produce xrays, increasing quantity (amplitude of curve)

Question 37

Know what happens as the atomic number of the target material goes up

Answer 37

As it goes up, so does the average energy, quantity of photons, and the position of the discrete line of the spectrum.