The 10,000,000,000-Volt question: What is the best choice of proton energyto drive a pulsed spallation neutron source?

In pulsed spallation neutron sources, higher proton beam current or higher proton energy brings higher proton beam power, and from greater beam power come more neutrons. Consequently, accelerator scientists and target systems designers conceive systems to produce ever-higher intensities of neutrons, and the question arises: What is the best choice of proton energy to drive a pulsed spallation neutron source? Meanwhile target engineering, radiatio n shielding, and neutronic coupling to moderators must be accomplished effe ctively. This paper addresses the title question from the target side, asse ssing the neutron yield, the distribution of leakage neutrons, and the powe r density distribution as functions of proton energy. (C) 1999 Elsevier Sci ence B.V. All rights reserved.