U.S. Particle Accelerator School
Neutron Beams and Accelerators course
Sponsoring University:
The University of Texas at Austin
Course:
Neutron Beams and Accelerators
Instructor:
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.