Results From the Laserwire Emittance Scanner and Profile Monitor at CERN's Linac4

Thomas Hofmann, Gary Boorman, Alessio Bosco, Stephen Gibson, Uli Raich, Federico Roncarolo

Research output: Chapter in Book/Report/Conference proceedingConference contribution


A novel, non-invasive, H− laserwire scanner has been tested during the beam commissioning of CERN’s new Linac4. Emittance measurements were performed at beam energies of 3 and 12 MeV with this new device and were found to closely match the results of conventional slit-grid methods. In 2015, the configuration of this laserwire scanner was substantially modified. In the new setup the electrons lib- erated by the photo-detachment process are deflected away from the main beam and focused onto a single crystal diamond detector that can be moved in order to follow the laser beam scan. The beam profiles measured with the new laserwire setup at 50 MeV, 80 MeV and 107 MeV are in good agreement with the measurements of nearby SEM grids and wire-scanners. The design of the final laserwire scanner for the full 160 MeV beam energy will also be presented. In Linac4 two independent laserwire devices will be installed in the transfer line to the BOOSTER ring. Each device will be composed of two parts: one hosting the laserwire and the electron detector and the second hosting the segmented diamond detector used to acquire the transverse profiles of the H0 beamlets.
Original languageEnglish
Title of host publication28th Linear Accelerator Conference
Subtitle of host publication25-30 September 2016, East Lansing, MI, USA.
PublisherJACoW Publishing
Chapter3 Technology
Number of pages5
ISBN (Electronic)978-3-95450-169-4
Publication statusPublished - May 2017

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