A New Collective Effect, High Flux Ion Accelerator

A new type of accelerator capable of producing a large flux of medium energy ions is discussed. The accelerator contains a charge neutral plasma in a magnetic field. Electron currents parallel to B→ heat the plasma electrons to an average energy kTe by the Joule process. The electrons try to escape from the plasma into an adjacent vacuum region along the magnetic field lines. In doing so they create a charge separation electric field which collectively accelerates the ions to energies ⪞10 kTe . The large resistivity necessary to obtain both the rapid heating and impedance matching to high power sources results from electron streaming instabilities in the plasma. Feasibility is investigated using a one dimensional, time dependent fluid model. In this model a realistic circuit is coupled to the plasma electrons. The resultant plasma heating and expansion are numerically followed in time and space. These calculations seem to imply that present day technology utilizing high voltage Blumlein transmission lines (Z ≃ 1Ω) seem capable of creating a 10 MeV proton stream with energy >10 kJ, and equivalent current density >10 kA/cm2