Production of X-Radiation

Question 1

production of dental x-rays

Answer 1

-filament circuit heats tungsten target in cathode
-thermionic emission, release of electrons
-electrons stay in electron cloud until high-voltage circuit is activated
-exposure button activates high-voltage circuit
-molybdenum cup in cathode directs electrons to tungsten target into anode
-electrons strike tungsten target (1% of energy –> x-rays)
-x-rays travel through unleaded glass window, tubehead seal, and aluminum disks
-size of beam restricted by lead collimator
-beam exits tubehead at PID

Question 2

types of x-rays produced

Answer 2

bremsstrahlung (braking)
characteristic

Question 3

braking radiation

Answer 3

the energy lost when an electron passes near the nucleus and is slowed from the tungsten atoms

Question 4

characteristic radiation

Answer 4

70 kP
1. high energy electron collides with an inner shell electron
2. both are ejected from tungsten atom leaving a hole
3. hole is filled by outer shell electron
4. loss of energy emitted as an x-ray photon

Question 5

definitions of x-radiations

Answer 5

primary radiation: penetrating x-ray beam that exits the tubehead, primary beam
secondary radiation: x-radiation created when primary beam interacts with matter, less penetrating… scatter radiation

Question 6

interactions of x-radiation

Answer 6

no interaction and no change in atom
completely absorbed by patient
scattered: compton scatter, coherent scatter

Question 7

compton scatter

Answer 7

x-ray photon is deflected from its path and loses energy

Question 8

coherent scatter

Answer 8

x-ray photon is unmodified

Question 9

what does the copper stem do

Answer 9

dissipates the heat

Question 10

electrons that have a -ve charge are attracted to the

Answer 10

+ve anode at high speeds

Question 11

vacuum tube

Answer 11

no other air molecules to allow electrons to be attracted