Accelerator and beamline upgrades at the AMS facility of GNS Science, New Zealand

Abstract This facility report discusses progress and outcomes of three major upgrade projects on the AMS facility at GNS Science, New Zealand. Converting the EN-tandem accelerator from a belt-driven charging system to a Pelletron has reduced the fluctuations on the terminal voltage by at least one order of magnitude. The Pelletron system has been operating for ca . 10,000 h and without problems. Interference-free detection of 26 Al 7+ is now possible with a new beamline that features a Wien velocity filter dispersing perpendicular with respect to the analysing magnet’s bending plane. The detector spectra for 10 Be 3+ and, to a lesser degree, for 14 C 4+ have lower backgrounds than in the old setup. Computer control of ca . half of all parameters along the AMS beamlines is implemented through a distributed network built from a combination of off-the-shelf and in-house built electronic interfaces. Separate from this network is AMS measurement control, for real-time measurement of isotope detector signals and control of the isotope-switching part of the inflection system. Current projects are replacement of the AMS measurement control system and expansion of the parameter control network to all beamlines.