X-ray equipment Flashcards
1
Q
Why is the x-ray casing filled with mineral water?
A
- Insulates electricity (prevents volts getting from tube to patient)
- Filters low energy photons from beam
- Removes heat from glass window via convection
2
Q
Why is there a lead lining?
A
To stop x-rays getting out and hitting the operator.
3
Q
What do rectifiers do?
A
Produce direct current thus cathode always connected to negative and anode connected to positive.
4
Q
Why is there a beryllium window?
A
Exit port- sealed to keep mineral oil in situ.
It is low attenuation to preserve the most useful proportion of the beam.
5
Q
What is immediately outside the exit port?
A
Aluminium filter to remove low energy photons that would add to the patients dose without producing any diagnostic information.
Legal required filtration:
- Below 70kV = 1.5mm of Al
- Above 70kV = 2.5mm of Al
