| The design of ion drivers for warm dense matter and high energy density physics applications and heavy ion fusion involves the acceleration and compression of intense ion beams to a small spot size on the target. Typically, ion beam acceleration and transport in vacuum is provided by a periodic focusing accelerator. Then, a dense background plasma is used to neutralize the beam space-charge during the longitudinal compression process. Finally, additional transverse focusing can be provided by a strong (several Tesla) final focus solenoid. In this thesis, the transport properties of an intense ion beam pulse propagating in an ion driver are investigated by making use of advanced numerical particle-in-cell simulations and reduced analytical models.;In particular, in order to study the properties of an intense beam quasi-equilibrium matched to a periodic focusing lattice, a numerical scheme is developed that allows for the quiescent formation of a matched beam distribution. Also, the problem of controlling the transverse beam envelope by variations in the lattice amplitude is addressed, and a detailed quantitative analysis of the associated halo particle production is performed. Ion beam pulse transport though a dense background plasma is investigated with emphasis on the effects of a weak solenoidal magnetic field (∼100 G), which can be present inside the long drift section due to the fringe fields of the strong final focus solenoid. In particular, whistler wave excitation and the effects of self-focusing on ion beam propagation through a background plasma along a solenoidal magnetic field are analyzed. Finally, the feasibility of using a weak (∼100 G) collective focusing lens for a tight final focus of the ion beam is investigated. The results of the thesis research are analyzed for the parameters characteristic of the Neutralizing Drift Compression Experiment (NDCX-I) and its planned upgrade (NDCX-II). |
