Electron Target Interaction

Question 1

Incandescent is…

Answer 1

white, glowing, luminous with intense heat

Question 2

What is thermionic emission?

Answer 2

emission of electrons from a heated surface

Question 3

is the filament current high or low voltage?

Answer 3

low, but high ampere

Question 4

What are thermions?

Answer 4

They are electrically charged particles that appear from a substance undergoing incandescent

Question 5

what are the 4 special conditions for x ray production?

Answer 5

1. you need source of electrons
2. you need high voltage
3. you an appropriate target material
4. you need a vacuum tube

Question 6

how much amp is required to heat up the filament?

Answer 6

4 amps or more

Question 7

what happens when you supply the filament with low voltage?

Answer 7

cathode become incandescent, the electrons starts to form space charge, thermionic emission occurs, then the focusing of electrons, focusing cup directs electrons to anode.

Question 8

what is the function of focusing cup?

Answer 8

because it is a more negative charge than the electrons that formed a space cloud, it forces the electrons to form a stream.

Question 9

the narrower the _____ _____, the ______ the focus, the sharper the image

Answer 9

electron beam, smaller

Question 10

when there is a difference in charge between cathode and anode, you created a …..

Answer 10

potential difference.

Question 11

what causes the beam of electrons to rush from cathode to anode?

Answer 11

potential difference.

Question 12

how fast do electrons travel?

Answer 12

half the speed of light

Question 13

what is electron stream also know as?

Answer 13

cathode rays or tube current, measured with mA

Question 14

at 80kVp, only ____ % is x-ray, ______ of energy is heat

Answer 14

0.6%, 99.4%

Question 15

what is the primary fxn of vacuum condition?

Answer 15

keeps the cathode and anode isolated. no gas molecules to encounter