Evaluation Summary

Practical systems for beam direct conversion are re quired to recover the energy from ion beams at high eciency and at very high beam power densities in the environment of a highpower, neutralinjection system. Such an experiment is now in progress using a 120kV beam with a maximum total current of 20 A. After neu tralization, the H+ component to be recovered will have a power of approximately 1 MW. A system testing these concepts has been designed and tested at 15 kV, 2 kW in preparation for the fullpower tests. The engineering problems involved in the fullpower tests aect electron suppression, gas pumping, voltage holding, diagnostics, and measurement conditions. Planning for future ex periments at higher power includes the use of cryopumping and electron suppression by a magnetic field rather than by an electrostatic field. Beam direct conversion for large fusion experiments and reactors will save millions of dollars in the cost of power supplies and electricity and will dispose of the charged beam under conditions that may not be possible by other tech niques