A method, apparatus and system for producing a desired spatial temperature distribution across a workpiece. The method includes irradiating a plurality of areas on a surface of the workpiece to create localized heating of the workpiece in those areas, to produce the desired spatial temperature distribution in the workpiece, and the apparatus includes means for carrying out the method. The system includes a locator for locating the workpiece in a desired position relative to an energy source, and an irradiance system for carrying out the method. The system further includes a processor circuit in communication with the irradiance system, and a radiation-absorbing environment. The irradiance system includes a measuring system and at least one energy source for directing radiation to the surface of the workpiece.