Design by numerical simulation of an in situ alpha spectrometer operating at ambient air pressure D. Degrelle, J. Venara, M. Ben Mosbah, M. Cuozzo, C. Mahé and R. Serrano EPJ Web Conf., 225 (2020) 06004 Published online: 20 January 2020 DOI: 10.1051/epjconf/202022506004