Resistive hose growth of intense ion beams propagating in air

The growth of the resistive hose instability for intense proton beams is examined using three-dimensional particle-in-cell simulations. The simulation results are compared with a time-dependent model of resistive hose growth that uses a spread-mass formulation and a time-dependent conductivity model. Radius tailoring of the beam head is shown to suppress high-frequency instability growth. In addition, the effects of a reduced-density plasma channel on the growth of the resistive hose instability is calculated