A non-invasive, compact laserwire system has been developed to measure the transverse emittance of an H- beam and has been demonstrated at the new LINAC4 injector for the LHC at CERN. Light from a low power, pulsed laser source is conveyed via fibre to collide with the H- beam, a fraction of which is neutralized and then intercepted by a downstream diamond detector. Scanning the focused laser across the H- beam and measuring the distribution of the photo-neutralized particles enables the transverse emittance to be reconstructed. The vertical phase-space distribution of a 3 MeV beam during LINAC4 commissioning has been measured by the laserwire and verified with a conventional slit and grid method.
@article{arxiv.1508.05750,
title = {Demonstration of a laserwire emittance scanner for the CERN LINAC4 H- Beam},
author = {T. Hofmann and K. O. Kruchinin and A. Bosco and S. M. Gibson and F. Roncarolo and G. Boorman and U. Raich and E. Bravin and J. K. Pozimski and A. Letchford and C. Gabor},
journal= {arXiv preprint arXiv:1508.05750},
year = {2015}
}
Comments
10 pages, 13 figures, to be published in Physical Review Special Topics - Accelerators and Beams