A diagnostic neutral beam injector (DNBI) [CRPP report LRP 710/01, CRPP-EPFL, 200 1; EPS Conf. Comr. Fusion Plasma Phys., 25A (2001) 365] has been installed on tokamak A configuration variable (TCV) [Plasma Phys. Control Fusion, 36 (1994) 13277; Plasma Phys. Control Fusion, 43 (200 1) A 16 1; Plasma Phys. Control Fusion, to be published] for the purpose of providing local measurements of plasma ion temperature, velocity and impurity density by Charge exchange recombination spectroscopy (CXRS) [EPS Conf. Contr. Fusion Plasma Phys., 25A (2001) 365]. The system recently underwent a technical upgrade, which allowed to increase the full neutral beam current density by a factor of two (from 0.5 to 1 A at 52 keV injection energy) and to extend the operational range of the diagnostic. This was achieved by means of a new, larger ion source, with an increased extraction area and corresponding enhancements of the power supplies. (C) 2003 Elsevier B.V. All rights reserved.