physics Flashcards
what are radiographs?
Images created by X-rays which have been projected through an object & then interacted with a receptor.
why are radiographs useful?
diagnose
help with treatment planning
monitor disease
Can show normal anatomy & pathology
X-rays are a form of what?
electromagnetic radiation
what is electromagnetic radiation?
The flow of energy created by simultaneously varying
electrical & magnetic fields
represented as a sine wave
what are Electromagnetic properties?
No mass
No charge
can travel in a vacuum,
Always travels at “speed of light”
671 million mph
EM radiation involves the movement of energy as
“packets of energy” known as?
photons
Energy usually measured in?
electron volts
ELECTRONS ARE FIRED AT WHAT at a very high speed?
atoms
the dental xray unit consist of what?
Tubehead
- Collimator
- Positioning arm
- Control panel
- Circuitry
what are the electricity fundamentals? what do they do?
Current - Flow of electric charge
Voltage- Difference in electrical potential between 2 points in
an electrical field
Transformers- alter the voltage (& current) from one circuit to
another
X-ray units have generators which modify the alternating current so
that it mimics a constant direct current what is this process known as?
rectification
what is the alternating current?
what is the direct current?
ac-flow repeatedly reverses direction
dc-constant unidirectional flow
Dental X-ray unit requires what type of current?
and what type of voltage?
direct current
2 types of voltage
One as high as 10s of thousands of volts
* One as low as around 10 volts
what is the xray beam made up of?
millions of X-ray photons directed in the
same direction
what is the xray production?
Electrons go towards atoms at very high speed as they collide the kinetic energy of these electrons is converted to heat &
electromagnetic radiation
The X-ray photons are aimed at a subject
