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TY - CONF AU - Gibson, S.M. AU - Boorman, G.E. AU - Bosco, A. AU - Gabor, C. AU - Hofmann, T. AU - Kruchinin, K.O. AU - Letchford, A.P. AU - Pozimski, J.K. AU - Roncarolo, F. AU - Savage, P. ED - Petit-Jean-Genaz, Christine ED - Arduini, Gianluigi ED - Michel, Peter ED - Schaa, Volker RW TI - A Fibre Coupled, Low Power Laserwire Emittance Scanner at CERN LINAC4 J2 - Proc. of IPAC2014, Dresden, Germany, June 15-20, 2014 C1 - Dresden, Germany T2 - International Particle Accelerator Conference T3 - 5 LA - english AB - The new LINAC4 will accelerate H⁻ ions to 160 MeV and ultimately replace the existing 50 MeV LINAC2 in the injector chain for the LHC upgrade. During commissioning in 2013, a laserwire scanner and diamond strip detector were installed for non-invasive emittance measurements of the 3 MeV H⁻ beam. Synergy with the 3 MeV H⁻ Front End Test Stand at RAL, has stimulated collaborative development of a novel laserwire system. A low peak power (8kW) pulsed laser is fibre-coupled for remote installation and alignment free operation. Motorized focusing optics enable remote control of the thickness and position of the laserwire delivered to the vacuum chamber, in which the laser light neutralises a small fraction of H⁻ ions. Undeflected by a dipole magnet, these H atoms drift downstream, where their spatial profile is recorded by a highly sensitive diamond strip detector with ns-time resolution. We present first tests of the laserwire emittance scanner, including measurements of the photo detachment signal with respect to the background from residual gas interactions. The first laserwire transverse beam profile and emittance measurements are compared with conventional slit-grid diagnostics. PB - JACoW CP - Geneva, Switzerland SP - 3725 EP - 3728 KW - laser KW - emittance KW - linac KW - detector KW - background DA - 2014/07 PY - 2014 SN - 978-3-95450-132-8 DO - 10.18429/JACoW-IPAC2014-THPME190 UR - http://jacow.org/ipac2014/papers/thpme190.pdf ER -