  Luminosity-driven channeling extraction has been observed for the first time
in a 900 GeV study at the Fermilab Tevatron. This experiment, Fermilab E853,
demonstrated that useful TeV level beams can be extracted from a
superconducting accelerator during high luminosity collider operations without
unduly affecting the background at the collider detectors. Multi-turn
extraction was found to increase significantly the efficiency of the process.
The beam extraction efficiency was about 25%. Studies of time dependent effects
found that the turn-to-turn structure was governed mainly by accelerator beam
dynamics. An investigation of a pre-scatterer using the accelerator flying wire
system showed that a fiber could produce a significant extracted flux,
consistent with expectations. Based on these results, it is feasible to
construct a parasitic 5-10 MHz proton beam from the Tevatron collider.
