X-ray Tube Physics and Calculations

Vocabulary and key physical concepts related to X-ray tube operation, electron beam power, and radiation wavelength calculations.

Minimum Wavelength ($\lambda_{\min}$)

The shortest wavelength emitted in continuous X-ray production, occurring when an electron converts all of its kinetic energy into a single photon via the relation $\lambda_{\min} = \frac{h c}{e V}$.

Operating Potential Difference ($V$)

The accelerating voltage applied across an X-ray tube to give electrons kinetic energy, specified as $40\,\text{kV}$ ($4.0 \times 10^{4}\,\text{V}$).

Tube Current ($I$)

The electric current carried by the stream of electrons from the cathode to the anode, given as $15\,\text{mA}$ ($1.5 \times 10^{-2}\,\text{A}$).

Planck's Constant ($h$)

A fundamental physical constant relating the energy of a photon to its frequency, given as $6.63 \times 10^{-34}\,\text{J s}$.

Speed of Light ($c$)

The speed of electromagnetic radiation in a vacuum, given as $3.0 \times 10^{8}\,\text{m/s}$.

Electronic Charge ($e$)

The magnitude of electric charge carried by an individual electron, given as $1.6 \times 10^{-19}\,\text{C}$.

Total Energy Delivered per Second

The electrical power delivered by the electron beam upon striking the target, calculated using the product of potential difference and current ($P = V I$).

Rate of Heat Generation in the Anode

The thermal power dissipated at the target due to electron collision, equal to $99\%$ of the total electrical power delivered by the electron beam.