Monoenergetic acceleration of high-charge ion bunches to GeV-scale energies by the combination of an intense relativistic electron beam and a laser-produced ionization front

Compact heavy ion accelerators find numerous applications, ranging from heavy ion fusion to carbon ion radiotherapy and testing radiation-hardened electronics. The demand could be met by developing high-gradient (hundreds of MeV/u) high-charge (~μC ) traveling wave plasma accelerators capable of accelerating the ions from their resting state to relativistic energies. We will discuss a novel ion acceleration regime termed Counter-propagating ionization Front Acceleration (CFA), utilizing counter-propagating Ionization Front (IF) and high-current Relativistic Electron Beam (REB). Theoretical modeling and 3D PIC simulations demonstrate the possibility of achieving ~250MeV/m acceleration over a meter distance using typical REBs produced by induction voltage adders (tens of nanosecond duration, few-MeV energies, tens of kA current) propagating through a tube filled with gas undergoing laser-driven ionization. The overall efficiency of a CFA can be high because the energy source is the REB, while the laser is used to produce an ionization front propagating with a pre-determined velocity. A unique energy conversion mechanism – from the REB to electromagnetic fields and into the ions – will be discussed, as well as the limits on the accelerated ion charge, acceleration gradient, energy spread, and wall-plug acceleration efficiency.