Linear beam collective ion acceleration for fusion applications

At the University of Maryland, studies of the collective acceleration of protons and heavy ions using a Luce diode configuration have been underway for several years. Systems of floating electrodes and/or slow-wave structures downstream of the diode have been investigated in an attempt to increase the accelerated ion energy. Using a 1.5 MeV, 30 kA, 30 ns electron beam pulse, proton energies in excess of 16 MeV and heavy ion (carbon, nitrogen) energies greater than 50 MeV have been achieved. Typical ion current is estimated to be 1 kA or greater, and the collective accelerating field in the post diode region has been measured to be greater than 100 MV/m. The possibility of achieving heavy ion pellet fusion by using collective ion accelerators of this type as injectors for higher energy accelerators will be discussed in the context of observed ion beam properties.