Production of Xrays Flashcards
What is the domestic electricity supply in voltage and in current?
Voltage = 220/240 volts
Current = 40 Hz per second
What is the main domestic supply?
Main domestic supply = usually 13 amp current
How many amps is required to fuse a circuit?
3, 5 or 13 amps depending on what’s being supplied.
Immersion heating, old cookers etc will require a lower current supply.
True or false?
False.
They will require a larger current supply = 30 amps
What does an X-ray tube contain?
All the mechanisms required to convert the domestic electricity supply into the ionising radiation X-rays that are used for taking radiographs.
Control panel
The tube head
What does the control panel allow us to modify?
Allows us to modify the duration of exposure depending on:
- Size of the patient
- The area of the exposure
- The type of film being taken (eg. Bitewing, periapical etc.)
What happens at the tube head?
Here the domestic electricity supply is converted to xrays that are exposed to the patient
The filament (cathode) in the X-ray tube is made of tungsten.
Why is it made of this material?
As tungsten has a very high melting point.
During the production of X-rays there is high heat generation.
Tungsten has a high tensile strength which means it can be pulled into a very fine wire before it breaks making it fit for purpose.
How many mA (current) are passed along the cathode?
8-10mA
As the current entering the machine is 13 amps, it must pass through a step down transformer.
What is this made up of?
Where is it placed in?
This is made of a large coil of copper wires and is placed in the tube head
What happens to the electrons when a current passes along the filament?
What does this result in?
They become excited.
Results in wire getting hot and light can potentially be given off.
Why do the electrons in the outer shell get lost?
As they are not held tightly within their orbit
What forms around the cathode?
Electron cloud forms around the cathode
