Phase space acceptance of LMF transport schemes

Three different ion beam transport schemes (achromatic lens, wire-guided transport, and Z-discharge channel) for the light ion beam driver for the Laboratory Microfusion Facility (LMF) are examined analytically. For each case the phase space acceptance area is investigated, including the effects of angular momentum. It is shown that, in real diode/transport configurations, there will be some angular momentum (i.e. φ₀≠0) created, e.g. by combinations of diode microdivergence, beam steering errors, foil scattering, and gas scattering. Both the ballistic/lens case and the channel case can accept φ₀=0 beams if they can be made, and can also tolerate certain amounts of φ₀≠0. On the other hand, the wire case requires φ₀≠0 in a carefully prepared manner. It is concluded that, in regard to angular momentum, the baseline ballistic case is the most accepting transport scheme. The channel transport scheme is less accepting. The wire transport scheme is the least accepting because it requires a tailored nonzero φ₀ distribution to be fully accepted