The role of antihydrogen formation in the radial transport of antiprotons in positron plasmas

Simulations have been performed of the radial transport of antiprotons in positron plasmas under ambient conditions typical of those used in antihydrogen formation experiments. The parameter range explored includes several positron densities and temperatures, as well as two different magnetic fields (1 and 3 T). Computations were also performed in which the antihydrogen formation process was artificially suppressed in order to isolate its role from other collisional sources of transport. The results show that, at the lowest positron plasma temperatures, repeated cycles of antihydrogen formation and destruction are the dominant source of radial (cross magnetic field) transport, and that the phenomenon is an example of anomalous diffusion. (paper)