Journal Article

Acceleration in the linear non-scaling fixed-field alternating-gradient accelerator EMMA

Saveliev, Y., Koscielniak, S., Buckley, R. K., Pasternak, J., Holder, D. J., Johnstone, C., Kalinin, A., Kelliher, D. J., Machida, S., Williams, P. H., Jones, L. B., Moss, A., McKenzie, J. W., Keil, E., Méot, F., Rao, Y-N., Hill, S. F., Marinov, K., D’Arcy, R., Clarke, J. A., Orrett, J., Owen, H. L., Yokoi, T., Jackson, F., Martlew, B., Hill, C., Trbojevic, D., Wheelhouse, A., Goudket, P., Middleman, K. J., Berg, J. S., Kirkman, I. W., Garland, J. M., Poole, M. W., Ibison, M. G., Weston, T., Bliss, N., Smith, R., Edgecock, R., Tzenov, S., Muratori, B. D., Marks, N., Smith, S. L., Jones, J. K., Peach, K. J., Barlow, R., McIntosh, P. A., Wolski, A., Jamison, S. P., Sheehy, S. L., Scott, D. J., Shepherd, B. J. A., Craddock, M. K., Griffiths, S., Giboudot, Y., Hock, K. M.

2012

Overview

In a fixed-field alternating-gradient (FFAG) accelerator, eliminating pulsed magnet operation permits rapid acceleration to synchrotron energies, but with a much higher beam-pulse repetition rate. Conceived in the 1950s, FFAGs are enjoying renewed interest, fuelled by the need to rapidly accelerate unstable muons for future high-energy physics colliders. Until now a ‘scaling’ principle has been applied to avoid beam blow-up and loss. Removing this restriction produces a new breed of FFAG, a non-scaling variant, allowing powerful advances in machine characteristics. We report on the first non-scaling FFAG, in which orbits are compacted to within 10 mm in radius over an electron momentum range of 12–18 MeV/c. In this strictly linear-gradient FFAG, unstable beam regions are crossed, but acceleration via a novel serpentine channel is so rapid that no significant beam disruption is observed. This result has significant implications for future particle accelerators, particularly muon and high-intensity proton accelerators. Rapid particle acceleration is possible using a fixed-field alternating-gradient machine—but ‘scaling’ in its design has been necessary to avoid beam blow-up and loss. The demonstration now of acceleration in such a machine without scaling has positive implications for future particle accelerators.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/766/419 / 639/766/930 / ACCELERATION / ACCELERATORS / Atomic / Beams (radiation) / Channels / Classical and Continuum Physics / Complex Systems / Condensed Matter Physics / ELECTRONS / MAGNETS / Mathematical and Computational Physics / Molecular / MUONS / Optical and Plasma Physics / Orbits / PARTICLE ACCELERATORS / Particle physics / PHYSICS / Physics and Astronomy / PROTONS / SERPENTINE / SYNCHROTRONS / Theoretical