ASTER report status and upgrades

Full text: ASTER (CEREGE, Aix en Provence, France) is a HVEE 5MV AMS in operation since 2007 within the LN2C (Laboratoire National de Nucléides Cosmogéniques, French national facility for cosmogenic nuclides). ASTER measures in routine around five thousand samples per year dispatched between ¹⁰Be, ³⁶Cl and ²⁶Al. Initially delivered with the HVEE SO-110B, ASTER has been upgraded in 2016 with the SO-110-C head source slightly increasing the output currents for ²⁷Al- and ⁹BeO-. This source is now used for all ¹⁰Be and ²⁶Al measurements while the previous source is dedicated to ³⁶Cl. We will present several tests and performances of the SO-110-C and how it is operated to ensure high quality routine measurements (high level and stable current) with a minimum cleaning procedure. In December 2019, a new line incorporating a gas-filled magnet was installed. Despite the progress made by the new source, this upgrade will be used to further improve the overall efficiency of ²⁶Al measurements by producing at least an order of magnitude higher negative ion beam in the ion source by injecting AlO- rather than Al-. Since the isobaric interfering MgO- is also produced, separation of these isobars becomes imperative. This new beamline thus endowed a multi-anode gas ionization chamber (GIC) and a 120 degrees (450 mm radius) gas-filled magnet (GFM) to reduce the initial intensity of Mg combined to realize this preliminary test. Due to the pandemic situation this extension is still under development but preliminary tests will be presented. We would like to dedicate this work to our late colleague and friend Didier Bourlès († 26/04/1955 – 01/03/2021).