An Elastic Wave Method for the Measurement of Pulse-Power Density

Experiments have shown that in addition to the well-known radiation pressure, another more efficient thermal mechanism results in the production of an elastic stress wave when an energy pulse is absorbed at the surface of an elastic body. This mechanism permits measurement of the peak-power density of pulses of electromagnetic energy by the use of an energy-absorbing surface, an elastic wave sensor and an indicating device. Analysis and experiments will be described to illustrate the operation of this measurement system when it is actuated by microwave pulses, pulses of light from a laser or a stroboscopic lamp and by a pulsed beam of electrons in an evacuated chamber.