  We investigate the possibility of tracking individual hydrogen micro-spheres
from an internal pellet target. Such a method aims to provide the primary
vertex of a reaction to within about 100 micrometres, without utilizing any
detector response. Apart from background considerations the knowledge of the
reaction vertex may be essential for the reconstruction of many physics
channels. This is in particular true for the study of the Psi(3770) decay into
D-mesons planned at the PANDA detector at the future FAIR facility. Here, the
reconstruction of displaced vertices is especially difficult since neutral
particles are involved.
  Studies with a pellet target at The Svedberg Laboratory, Uppsala, show the
technical feasibility of a tracking system utilizing fast CCD line-scan
cameras. Simulations for the reaction p-bar p to Psi(3770) to D+ D- prove the
large impact such a system would have on the data taking and reconstruction at
PANDA.
