Radian

A unit of angular measurement equal to the angle subtended at the center of a circle by an arc whose length is equal to the radius of the circle.
Example: 1 radian = ~ 57.3 degrees; 2π radians = 360 degrees

Raman Effect

Part of the energy in a photon is transferred to (or from) the vibrational/rotational energy of a molecule.

Ramper

Power controls for accomplishing the ramping steps; may be computer-controlled.