Demonstration of a laserwire emittance scanner for the CERN LINAC4 H- Beam

TL;DR

This paper presents a non-invasive laserwire system for measuring the transverse emittance of an H- beam at CERN's LINAC4, demonstrating its effectiveness by comparing results with traditional methods.

Contribution

A compact laserwire system has been developed and demonstrated for non-invasive transverse emittance measurement of H- beams at CERN LINAC4.

Findings

Successfully measured vertical phase-space distribution at 3 MeV.

Verified laserwire measurements against conventional slit and grid method.

Demonstrated the system's potential for real-time beam diagnostics.

Abstract

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.