U.S. Particle Accelerator School

Neutron Beams and Accelerators course

Sponsoring University:

The University of Texas at Austin


Neutron Beams and Accelerators


Alessandro Ruggiero, Brookhaven National Laboratory

This course will study the use of Particle Accelerators for the production of intense and high-flux neutron beams, as an alternative to Nuclear Reactors. Described and evaluated will be: the generation process by Spallation of protons on heavy nuclei from which neutrons are expelled, and the characteristics of the needed proton beam - a few Megawatt of power, a few GeV of energy at most, one or so mA of average beam intensity. The accelerator chain for Spallation Neutron Sources will be considered. Such a chain is typically made of a front-end which includes the negative-ion source, a Linear Accelerator, and a Compressor Ring (Synchrotron or Accumulator) where the beam is injected and compressed to the required pulse length, then extracted and  made to impinge on a target for the production of neutrons. We shall examine all the details and the requirements of the several acceleration steps. We shall study the process of multi-turn injection by the method of charge exchange; the space-charge limitations; the instabilities that one could expect because of the very large beam intensity; the control of the beam losses to avoid activation of the accelerator components; the formation of beam halo and the consequent need for scraping; and the implications of requiring that the compressor-accelerator operates well below the transition energy. We will contrast the different possible accelerator architectures. A course on accelerators or some accelerator experience is required.