Date Time Share Dark Matter Particle Explorer Reports Most Precise Measurements of Cosmic Ray Proton and Helium Spectra above TeV and Reveals Chinese Academy of Sciences The Dark Matter Particle Explorer (DAMPE) collaboration reported the precise measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV energies on May 18, 2021. For the first time, DAMPE reveals a softening structure at about 34 TeV energies in the helium spectrum with a high significance (~4.3σ). Together with the softening energy of the DAMPE proton spectrum, the results are consistent with a charge-dependent softening energy of protons and helium nuclei. The common softening is likely an imprint of a nearby cosmic ray source, e.g., a supernova remnant. The softening energy, which is likely Z-dependent for protons and helium nuclei, corresponds to the acceleration upper-limit of such a nearby source.