The Forbush decrease (FD) represents the rapid decrease of the intensities of charged particles accompanied with the coronal mass ejections or high-speed streams from coronal holes. It has been mainly explored with the ground-based neutron monitor network, which indirectly measures the integrated intensities of all species of cosmic rays by counting secondary neutrons produced from interaction between atmospheric atoms and cosmic rays. The space-based experiments can resolve the species of particles but the energy ranges are limited by the relatively small acceptances except for the most abundant particles like protons and helium. Therefore, the FD of cosmic-ray electrons and positrons have just been investigated by the PAMELA experiment in the low-energy range (<5 GeV) with limited statistics. In this paper, we study the FD event that occurred in 2017 September with the electron and positron data recorded by the Dark Matter Particle Explorer. The evolution of the FDs from 2 GeV to 20 GeV with a time resolution of 6 hr are given. We observe two solar energetic particle events in the time profile of the intensity of cosmic rays, the earlier, and weaker, one has not been shown in the neutron monitor data. Furthermore, both the amplitude and recovery time of fluxes of electrons and positrons show clear energy dependence, which is important in probing the disturbances of the interplanetary environment by the coronal mass ejections.

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The DArk Matter Particle Explorer (DAMPE) is a satellite-borne particle detector launched on December 17th, 2015, with different scientific objectives, looking for signatures of Dark Matter decay or annihilation, performing gamma-ray astronomy and providing precise measurements of galactic Cosmic Ray (CR) energy spectra. Accurate measurements of hadronic interaction cross sections play a key role in the determination of CR fluxes. The survival probabilities have been implemented to study hadronic interaction cross sections with the BGO calorimeter target for Carbon nuclei in a wide kinetic energy range from a few GeV to TeV, by using data collected by the DAMPE experiment. The results have been then compared with Geant4 simulations of the interaction cross-sections performed by adopting the Glauber-Gribov Model. The details of the measured hadronic interaction cross sections are here presented and discussed.

More than a century after the performance of the oil drop experiment, the possible existence of fractionally charged particles (FCPs) still remains unsettled. The search for FCPs is crucial for some extensions of the Standard Model in particle physics. Most of the previously conducted searches for FCPs in cosmic rays were based on experiments underground or at high altitudes.However, there have been few searches for FCPs in cosmic rays carried out in orbit other than AMS-01 flown by a space shuttle and BESS by a balloon at the top of the atmosphere. In this study, we conduct an FCP search in space based on on-orbit data obtained using the DArk Matter Particle Explorer (DAMPE) satellite over a period of five years. Unlike underground experiments, which require an FCP energy of the order of hundreds of GeV, our FCP search starts at only a few GeV. An upper limit of 6.2 × 10 −10 cm −2 sr −1 s −1 is obtained for the flux. Our results demonstrate that DAMPE exhibits higher sensitivity than experiments of similar types by three orders of magnitude that more stringently restricts the conditions for the existence of FCP in primary cosmic rays.