A hemispherical retarding field energy analyzer to characterize spatially and angularly extended electron beamsFabrice Cipriani, Frédéric Leblanc, Jean-Marie Illiano and Jean-Jacques BerthelierEur. Phys. J. Appl. Phys., 60 2 (2012) 21002DOI: https://doi.org/10.1051/epjap/2012120011