CERN Accelerating science

Published Articles
Report number	CERN-ACC-2015-302
Title	Laserwire Emittance Scanner at CERN Linac 4
Author(s)	Kruchinin, Konstantin (Royal Holloway, U. of London) ; Boorman, Gary (Royal Holloway, U. of London) ; Bosco, Alessio (Royal Holloway, U. of London) ; Bravin, Enrico (CERN) ; Gibson, Stephen (Royal Holloway, U. of London) ; Hofmann, Thomas (CERN) ; Karataev, Pavel (Royal Holloway, U. of London) ; Letchford, Alan (Rutherford) ; Pozimski, Jürgen (Imperial Coll., London) ; Raich, Uli (CERN) ; Roncarolo, Federico (CERN) ; Zocca, Francesca (CERN)
Publication	2015
Number of pages	4
In:	6th International Particle Accelerator Conference, Richmond, VA, USA, 3 - 8 May 2015, pp.MOPWI003
Subject category	Accelerators and Storage Rings
Abstract	Linac 4 presently under construction at CERN is designed to replace the existing 50 MeV Linac 2 in the LHC injector chain and will accelerate the beam of high current negative hydrogen ions to 160 MeV. During the commissioning a laserwire emittance scanner has been installed allowing noninvasive measuring of the emittance at 3 MeV and 12 MeV setups. A low power infrared fibre coupled laser was focused in the interaction region down to  150 um and collided with the ion beam neutralising negative ions. At each transverse laser position with respect to the ion beam the angular distribution of the neutral particle beamlets was recorded by scanning a diamond detector across the beamlet at a certain distance from the IP while the main beam of the H⁻ ions was deflected using dipole magnet installed upstream the detector. Measuring the profile of the beamlet by scanning the laser across the beam allows to directly measure the transverse phase-space distribution and reconstruct the transverse beam emittance. In this report we will describe the analysis of the data collected during the 3 MeV and 12 MeV operation of the Linac 4. We will discuss the hardware status and future plans.
Copyright/License	publication: © 2015-2024 The Author(s) (License: CC-BY-3.0)

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