Primary reference in terms of air kerma for ionizing radiation fields produced by an electrostatic electron accelerator Jean-Marc Bordy, Valentin Blideanu, Arnaud Chapon, Gabriel Dupont, Dorin Dusciac, Jean Gouriou, Frederic Laine and Maiwenn Le Roy Published online: 23 September 2019 DOI: 10.1051/metrology/201915003