Leda: A gamma-gamma coincidence spectrometer for the measurement of environment samples

This paper presents a new gamma-gamma coincidence spectrometer to measure the radioactivity in environmental samples. This system, called Leda, is made of 2 HPGe and 1 NaI(Tl). The different analysis channels (single, in coincidence or in anti-coincidence) possible thanks to the digital electronics are described. Results obtained with environmental samples are shown. Despite its low efficiency, this method improves the detection limits for all emitters due to its very low background, and thus decreases the counting time. •The new gamma-gamma coincidence spectrometer consists in 2 HPGe and 1 NaI(Tl).•Multiple analysis channels combining the energy losses in the different detectors.•The analysed channel depends on the radionuclide and on the sample type.•Efficiency calibration using standard sources or by MCNP_CP simulations.•Gain in terms of detection limits and counting time for all the radionuclides.