CC BY-NC-SA 3.0 UnportedPfotenhauer, S.M.Jäckel, O.Polz, J.Steinke, S.Schlenvoigt, H.-P.Heymann, J.Robinson, A.P.L.Kaluza, M.C.2020-08-122020-08-122010https://doi.org/10.34657/4115https://oa.tib.eu/renate/handle/123456789/5486We present a novel, cascaded acceleration scheme for the generation of spectrally controlled ion beams using a laser-based accelerator in a 'double-stage' setup. An MeV proton beam produced during a relativistic laser-plasma interaction on a thin foil target is spectrally shaped by a secondary laser-plasma interaction on a separate foil, reliably creating well-separated quasi-monoenergetic features in the energy spectrum. The observed modulations are fully explained by a one-dimensional (1D) model supported by numerical simulations. These findings demonstrate that laser acceleration can, in principle, be applied in an additive manner. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.enghttps://creativecommons.org/licenses/by-nc-sa/3.0/530Energy spectraLaser accelerationLaser-plasma interactionsNumerical simulationOne-dimensional (1D) modelsQuasi-monoenergeticThin-foil targetComputer simulationLaser fusionLaser produced plasmasLaser radiationProton beamsProtonsSpectroscopyBeam plasma interactionsArticle