The Positronium Science Group at UCR is looking for a qualified person to fill an experimental Postdoctoral Scholar position. Qualified candidates will have received a Ph.D. in plasma physics or a related field and have a demonstrated background in experimental plasma science. The Postdoctoral position involves (1) the creation of quasi-neutral electron-positron plasmas inside a cavity buried in a solid, (2) development of time-resolved diagnostics to characterize density and temperature of the evolving electron-positron plasmas. The Postdoctoral scholar will have access to a unique positron source delivering >10 million positrons per pulse in a small spot to load the buried cavity with positrons as well as copious secondary electrons created during the positron implantation and