D-He$sup 3$ experiments to simulate DT burns in TFTR have been proposed by members of the Fusion Studies Center at the University of Illinois. Some basic considerations, involved in planning these experiments, are discussed along with important results to be obtained from such measurements. It is argued that fusion-product orbits, instabilities, and other phenomena can be investigated by D-He$sup 3$ simulation of DT burns, before the TFTR is contaminated by tritium. This approach will allow changes in experimental design before subsequent DT burn studies. (auth)