X-ray production/ X-ray emission

Question 1

At 80 kVp, of all the energy in the electrons stream, ____ is converted to ____ and ____ is converted into ____.

Answer 1

99.4 %
Heat
0.6%
x-rays

Question 2

Of all the x-rays in the primary beam produced at 80 kVp, ___ is ___; and ___ is ___.

Answer 2

90%
Brems
10%
Characteristic

Question 3

What is the efficiency of x-ray production at 95 kVp with a tungsten target?

Answer 3

.703

Question 4

Wavelength is represented by the greek letter ___ whose symbol is ____.

Answer 4

Lambda
y (upside down y)

Question 5

The energy of a Brems photon is dependent on what?

Answer 5

The distance of the incident electron from the nucleus of the target atom

Question 6

To increase the probability of Characteristic radiation forming, the target should have a high…

Answer 6

Atomic number

Question 7

You have the following technique set on the control panel: 95 kVp, 200 mA, 1/20 sec. What is the minimum wavelength of any photon in the primary beam?

Answer 7

0.13A

Question 8

What is the useful range of wavelengths for diagnostic radiology?

Answer 8

0.1A to 0.5A

Question 9

What is the approximate energy of the maximum number of Brems photons produced with the following technique: 120 kVp, 200 mA, 1/5 sec?

Answer 9

40 keV

Question 10

Given that tungsten has 6 electron shells, what is the number of different characteristic x-ray energies that can be produced?

Answer 10

15

Question 11

As you proceed to the lower left end of the electromagnetic spectrum, the wavelength of the radiation at this end becomes…

Answer 11

Longer

Question 12

What is the maximum energy of any photon in the primary beam produced at 90 kVp using a tungsten anode (Z=74)?

Answer 12

90 keV

Question 13

Characteristic radiation will not be produced with a tungsten anode if the kVp falls below what value?

Answer 13

69

Question 14

What is the result of Characteristic radiation production?

Answer 14

• Characteristic photon
• Photoelectron
• Ion pair

Question 15

Given that the wavelength of a certain x-ray photon is 0.35A, what is the energy of the photon?

Answer 15

35.4 keV

Question 16

One incident (projectile electron from the cathode can undergo multiple interactions at the target. T/F

Answer 16

True

Question 17

Electromagnetic radiation is the transport of energy through space as a combination of…

Answer 17

Electric and magnetic fields

Question 18

As per the quantum theory of the behavior of x-rays, the photon energy is ____ proportional to its frequency.

Answer 18

Directly

Question 19

An electron with 70 keV may produce an x-ray photon with which of the following? 70, 20, 1 keV

Answer 19

Any of them

Question 20

The energy of a characteristic x-ray depends on the ______ ______ of the electron knocked out of the target atom and the binding energy of the electron that falls into it’s hole.

Answer 20

Binding energy

Question 21

Increasing the mA setting on the x-ray tube, with all other parts of the technique remaining the same, will result in…

Answer 21

More projectile electrons with the same energy

Question 22

Characteristic x-rays produced when an electron is knocked out of which electron shell have the best energy level for diagnostic imaging?

Answer 22

k Shell

Question 23

The energy of Bremsstrahlung x-rays…

Answer 23

Covers a wide spectrum of energy levels

Question 24

When the kVp is set in the range of 100-150 kVp, most of the x-rays produced are…

Answer 24

Bremsstrahlung

Question 25

The intensity of x-rays that are emitted through the heel of the target is ____ the intensity of x-ray that go towards the cathode side of the tube.

Answer 25

Less than

Question 26

You have a given x-ray tube. You supply is with single phase recited AC to produce x-rays. You then change the wiring to supply it with three pass 6 pulse rectified AC to produce x-rays. This change in power supply will cause a change in the maximum energy level of the characteristic photons produced. T/F

Answer 26

False

Question 27

A given radiograph requires 15 mAs and results in an exposure of 25 mR. What will the new exposure be if you change to 10 mAs?

Answer 27

16.7 mR

Question 28

What effect if any, does a filter have on the quality of the x-ray beam as it exits the filter?

Answer 28

It increases the quality