Physics 101-3

Question 1

Emissions of electrons from a heated surface

Answer 1

Thermionic Emission

Question 2

Electrically charged particles emitted by an incandescent substance

Answer 2

Thermions

Question 3

Electrical production of x-rays is possible under 4 conditions

Answer 3

1. Source of electrons (separation & focusing)
2. High voltage
3. Appropriate target material
4. Vacuum

Question 4

Bremsstrahlung Radiation

Answer 4

• incident electrons interact with force field

Question 5

Source of electrons

Answer 5

Cathode (filament, negative)

Question 6

Where electrons interact to produce x-ray photons

Answer 6

Anode (target, positive)

Question 7

Causes of separation of electrons

Answer 7

• cathode to become incandescent
• space charge to be generated
• thermionic emissions to occur

Question 8

• metal
• negatively charged
• directs electron stream to anode
• the narrower the electron beam, the smaller the focus, the sharper thr image

Answer 8

Focusing cup (focusing electrons)

Question 9

Application of a potential difference across the tube creates a difference in charge between the cathode and anode during x-ray exposure (kVp)

Answer 9

High voltage to produce high speed electrons

Question 10

• high negative charge in cathode (filament)
• potential difference generated causes the space charge electrons to rush from the cathode to anode

Question 11

incident election interacts with an inner shell electron

Answer 11

Characteristic Radiation

Question 12

Liberations of electrons

Answer 12

Thermionic emission to occur

Question 13

Source of electrons within the x-ray tube is a result of

Answer 13

Thermionic emission

Question 14

Application of a potential difference across the tube creates a difference in charge between the cathode and anode during x-ray exposure

Answer 14

Creates a high negative charge in cathode (filament)

Question 15

At 80kVp, only _____% of the energy is x-rays & over ____% of thr energy is heat

Answer 15

0.6 & 99.4

Question 16

Narrower the electron beam, the _____ the focus, the _____ the image

Answer 16

Smaller, sharper

Question 17

Application of a ________ across the tube creates a difference in charge between the cathode and anode during x-ray exposure

Answer 17

Potential difference

Question 18

How many amperes are required to heat the filament in the cathode

Answer 18

4 amperes and above

Question 19

Rhodium with Z number of

Answer 19

45

Question 20

Atomic number of target material affects both the _____ and _______ of xrays.

Answer 20

Number (quantity) & effective energy (quality)

Question 21

May occur only when the incident electron interacts with an inner-shell electron

Answer 21

Characteristic interaction

Question 22

As the energy of an x-ray beam is ________, the penetrability or quality of the xray beam is also _______.

Answer 22

Increased, increased

Question 23

Increased xray beam quality results in a more penetrating xray beam

Answer 23

Kilovoltage

Question 24

Has no effect on beam quality (penetrating capability)

Answer 24

mAs

Question 25

Affects both the quantity and quality of x-rays

Answer 25

Change in kVp

Question 26

Increased kVp means increased x-ray beam quality or penetrating capability, less patient absorption

Answer 26

Shorter wavelengths and higher frequency

Question 27

Increased kVp means

Answer 27

Increased xray quantity (exposure rate)