4 different X-ray tube limitations

1. Max tube power at lower kV
2. Max. mA limited by the power supply only
3. Tube power
4. Max. nominal high tension

Maximum tube power at lower kV

The fieldstrength is not high enough to accelrate the entire electron cloud around the filament.

Therefore the filament needs to be heated at higher temperature and is limiting the tube power by its lifetime.

Maximum tube power

The max. tube power is limited by the max. specific load on the focal spot.
This varies with the target material

Maximum high tension

    The max. accelration voltage is based on a risk assessment.
    Following will increase with max. HT:

  • Duration for conditioning
  • Frequency of discharges per period
  • Chance of breakdown of the HT cable
  • or its connection