radiation shield

(P,I) radiant power; intensity; radiation intensity. Energy of radiation striking a unit area per unit time. The SI unit of radiant power is J m-2 s-1.

The radiant power expressed per unit solid angle about the direction of the light.

The power from a point source generated in a solid angle: measured units = watts/steradian.

Total energy radiated from an object per solid angle of measurement. Standard measurement unit W sr-1.

The radiant flux per unit solid angle, as from a point source; units are watts per steradian (W sr−1). See intensity.

In radiometry, radiant intensity is a measure of the intensity of electromagnetic radiation. It is defined as power per unit solid angle. The SI unit of radiant intensity is watts per steradian (W·sr-1).