X-ray Tube Voltage

X-ray tube voltage refers to the high voltage applied between the anode and cathode within an X-ray tube. This voltage accelerates electrons emitted from the cathode, causing them to collide with the anode and generate X-rays.
The tube voltage determines the energy and penetrative power of the X-rays. Higher voltages produce X-rays with shorter wavelengths (hard X-rays), which carry higher energy and can penetrate denser materials more easily.
The relationship between tube voltage and wavelength can be calculated using the Duane-Hunt law. The shortest wavelength (λmin) is inversely proportional to the voltage. For example, at a tube voltage of 100 kV, the electrons accelerate to a maximum energy of 100 keV. Using the conversion constant 1.24 nm·kV, the shortest wavelength is calculated as:
Planck's constant E = hν = hc/λ [ J ] gives 1.24/100 keV = 0.0124 nm (0.124Å).
Additionally, the total X-ray intensity is generally proportional to the square of the tube voltage. Precise control of the voltage is therefore essential for optimizing image contrast and brightness in inspection applications.
For more information on the relationship between voltage and transmission power,
please refer to the Q&A section "What is the tube voltage for X-ray inspection systems?".