Child's Law - related to anode voltage
Description
First proposed by Clement D. Child in 1911, Child’s law states that the space-charge limited current (SCLC) in a plane-parallel vacuum diode varies directly as the three-halves power of the anode voltage Va and inversely as the square of the distance d separating the cathode and the anode.
For electrons, the current density J (amperes per meter squared) is written as shown here.
Related formulasVariables
| J | current density (A/m^2) (dimensionless) |
| ϵ0 | dielectric permittivity (F*m^-1) (dimensionless) |
| e | magnitude of the charge of the electron (C) (dimensionless) |
| me | electron mass (kg) (dimensionless) |
| Va | anode voltage (V) (dimensionless) |
| d | distance separating the cathode and the anode (m) (dimensionless) |