The Child-Langmuir Law describes the space-charge-limited current in a vacuum diode, establishing a relationship between the current density and the voltage applied across the diode. It is fundamental in understanding the operation of vacuum tubes and electron emission devices, predicting that the current density is proportional to the three-halves power of the anode voltage divided by the square of the distance between the electrodes.

Child-Langmuir Law

Space-charge-limited current occurs when the current in a vacuum or semiconductor diode is limited by the space charge effect, which is the accumulation of charge carriers in the vicinity of the cathode. This phenomenon is significant in devices where the emitted current exceeds the current that can be carried away by the electric field, leading to a saturation effect that limits the current flow.

space-charge-limited current

A vacuum diode is an electronic component that allows current to flow in only one direction, utilizing a vacuum to facilitate the movement of electrons from a heated cathode to an anode. It is a fundamental building block in early electronics, playing a crucial role in rectification and signal detection before the advent of semiconductor diodes.

vacuum diode

Current density is a measure of the electric current per unit area of cross-section in a material, crucial for understanding how current flows through conductors. It is a vector quantity, typically denoted by J, and is fundamental in analyzing the distribution of currents in electrical circuits and devices.

current density

voltage applied across the diode

operation of vacuum tubes

electron emission devices

three-halves power

Anode voltage is the electrical potential difference between the anode and cathode in a circuit, crucial for the operation of devices like vacuum tubes and diodes. It influences the flow of electrons, impacting the efficiency and performance of electronic components and systems.

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