Dispersion matching at the injection from a high-intensity linac to a circular accelerator

Dispersion matching is known to be important in injecting a high-intensity beam from a linac to a circular accelerator. As a ring bunch is usually a superposition of a number of linac bunches, it is required to take both of the momentum centroid jitter and the momentum spread into consideration in the dispersion matching at injection. As the momentum centroid jitter affects the transverse beam dynamics through the dispersion without space-charge and the momentum spread that with space-charge, both of the dispersions should be optimized at the ring injection to realize an ideal matching. For this purpose, we have established a formalism to calculate the dispersion with space-charge swiftly for a bunched beam. The optimization procedure based on this formalism is demonstrated for an actual beam transport line as a practical example. Then, the validity of the procedure is confirmed with particle simulations.