Waseda researchers measure boron flux in high-energy cosmic rays with CALET
Cosmic rays (CR) constitute high-energy particles that mainly originate outside our solar system. These primary CR interact with interstellar matter to produce secondary CR. The secondary nature of their origin is reflected in the higher abundance of light elements, such as boron (B), in secondary CR relative to the solar system. Likewise, the primary CR can be quantified in terms of the amount