With the recent theoretical and experimental interest in laser acceleration, the issue of using dielectrics to support large accelerating fields has gained prominence. Various analyses have indicated that GV/m accelerating fields should be possible in dielectric-based laser accelerators(1), as long as illumination times are very short(2). Dielectric accelerators may also be powered directly by charged particle beams, via wake-field excitation(3,4). This mechanism has been studied in depth over the last several years, but with the maximum fields limited to 10's of MeV/m by the lack of ultra-short drive beams. According to scaling laws described below, however, the recently achieved 20 micrometers pulse-length beams obtained at the SLAC FFTB facility may give over GV/m longitudinal fields in dielectric wakefield accelerator systems. This possibility has led to a preliminary proposal, described here, to use this beam in ultra-high field dielectric wakefield (coherent Cerenkov excitation) experiments. The initial round of experiments are proposed here to take place in the context of the end of an E167 run, and uses very similar beam conditions as well as much of the interaction region hardware.