Feasibility study of a 1-MW pulsed spallation source

A feasibility study of a 1-MW pulsed spallation source based on a rapidly cycling proton synchrotron (RCS) has been completed. The facility consists of a 400-MeV H^- linac, a 30-Hz RCS that accelerates the 400-MeV beam to 2 GeV, and two neutron-generating target stations. The design time-averaged current of the accelerator system is 0.5 mA, and is equivalent to 1.04×10¹⁴ protons per pulse. The linac system consists of an H^- ion source, a 2-MeV RFQ, a 70-MeV DTL and a 330-MeV CCL. Transverse phase space painting to achieve a Kapchinskij-Vladimirskij (K-V) distribution of the injected particles is accomplished by the charge exchange injection and programming of the closed orbit during the injection. The synchrotron lattice uses FODO cells of 90° phase advance. Dispersion-free straight sections are obtained by using a missing magnet scheme. Synchrotron magnets are powered by a dual-frequency resonance circuit that excites the magnets at a 20-Hz rate and de-excites them at a 60-Hz rate, resulting an effective rate of 30 Hz, and reducing the required rf power by 1/3. Details of the study are presented