Long-pulse ion induction linac

Important issues for the long-pulse induction ion accelerator are (1) the development of high-current long-pulse ion injectors, (2) a method for precise modulation of ion energy for longitudinal pulse compression, (3) core material selection of reasonable construction cost and size, and (4) a realistic scheme for the ion beam transport at low-β region. At the present stage of our project, emphasis has been placed on the characterization of magnetic materials and the development of the long pulse, high flux, low emittance ion injectors. For the precise voltage modulation and cost effective selection of magnetic cores, we measured the response of various ferromagnetic materials under fast-pulse excitation. For the intense, long-pulse ion injectors, we propose drifting point-expanding plasma sources, which compress (smooth out) and expand (cool) the source plasma. These issues are discussed based on some experimental results.