Adventures in High-Temperature Resistive Emitter Physics

摘要

The next generation of resistively heated emitter pixels is expected to attain apparent temperatures more than a factor of two higher than presently achievable - in excess of 2000 K. The peak temperatures for the current generation of devices are determined by the balance between the power input to the pixel and the conductive loss of heat through the leg structures. At pixel temperatures higher than approximately 1500-2000 K, radiative losses will begin to dominate over conductive losses. We explore the physics of this regime and find that the peak temperature is determined primarily by the power input, emissivity and emitting area. The speed of radiatively limited pixels is also examined and found to be considerably more complicated than that of conductively limited pixels since both loss terms play significant roles in the pixel's dynamic behavior. In order to attain the higher temperatures required, development work will be required on two fronts: materials science and advanced, higher power drive circuitry. Some of the critical issues related to these tasks are discussed.