excitation

excitation

Addition of a discrete amount of energy to a system that changes it usually from a state of lowest energy (ground state) to one of higher energy (excited state). For example, in a hydrogen atom, an excitation energy of 10.2 electron volts is required to move the lone electron from its ground state to its first excited state. The excitation energy stored in excited atoms and nuclei is usually emitted as ultraviolet radiation from atoms and as gamma radiation (see gamma ray) from nuclei as they return to their ground states.

---

excitation [‚ek‚sī′tā·shən]

(atomic physics)

A process in which an atom or molecule gains energy from electromagnetic radiation or by collision, raising it to an excited state.

(control systems)

The application of energy to one portion of a system or apparatus in a manner that enables another portion to carry out a specialized function; a generalization of the electricity and electronics definitions.

(electricity)

The application of voltage to field coils to produce a magnetic field, as required for the operation of an excited-field loudspeaker or a generator.

(electronics)

The signal voltage that is applied to the control electrode of an electron tube. Also known as drive.

Application of signal power to a transmitting antenna.

(neuroscience)

A change in the electrical state of a neuron leading to an action potential.

(quantum mechanics)

The addition of energy to a particle or system of particles at ground state to produce an excited state.