The Dark Matter Particle Explorer (DAMPE, also known as "Wukong") collaboration has obtained a high-precision cosmic-ray boron spectrum in the energy range of 10GeV/n to 8TeV/n and, for the first time, discovered a spectral "hardening" feature near 182GeV/n. The relevant results have been published in Physical Review Letters.

The DAMPE satellite mission is equipped with the thickest bismuth germanate (BGO) calorimeter to date, providing an energy coverage more than twice that of previous space experiments. The plastic scintillator detector (PSD), developed by the Institute of Modern Physics, Chinese Academy of Sciences, has become the core detector for identifying cosmic-ray nuclei thanks to its outstanding charge measurement capability.

Using DAMPE data, researchers found a significant "hardening" feature in the boron spectrum around 182GeV/n, with a confidence level of 8 sigma. The study shows that the degree of hardening in the secondary boron spectrum is approximately twice that of primary cosmic rays (protons and helium nuclei) and is consistent with the hardening observed in the boron-to-carbon and boron-to-oxygen flux ratios.

These results are consistent with theoretical predictions that cosmic-ray boron is produced through spallation reactions involving primary cosmic rays (such as carbon and oxygen) and interstellar matter.

This discovery not only provides key evidence for studying cosmic-ray propagation processes but also offers valuable insights for refining existing theoretical models. The Dark Matter Particle Explorer (DAMPE) has set a new precision standard in measuring TeV-energy cosmic-ray spectra.

The research was jointly conducted by scientists from the Purple Mountain Observatory of the Chinese Academy of Sciences, the University of Science and Technology of China, the Gran Sasso Science Institute in Italy, and the University of Geneva in Switzerland.