Publications by authors named "G A de Nolfo"

Detailed measurements of the spectral structure of cosmic-ray electrons and positrons from 10.6 GeV to 7.5 TeV are presented from over 7 years of observations with the CALorimetric Electron Telescope (CALET) on the International Space Station.

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We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the Calorimetric Electron Telescope onboard the International Space Station over 6 yr, corresponding to the positive polarity of the solar magnetic field. The observed variation of proton count rate is consistent with the neutron monitor count rate, validating our methods for determining the proton count rate. It is observed by the Calorimetric Electron Telescope that both GCR electron and proton count rates at the same average rigidity vary in anticorrelation with the tilt angle of the heliospheric current sheet, while the amplitude of the variation is significantly larger in the electron count rate than in the proton count rate.

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We present the results of a direct measurement of the cosmic-ray helium spectrum with the CALET instrument in operation on the International Space Station since 2015. The observation period covered by this analysis spans from October 13, 2015, to April 30, 2022 (2392 days). The very wide dynamic range of CALET allowed for the collection of helium data over a large energy interval, from ∼40  GeV to ∼250  TeV, for the first time with a single instrument in low Earth orbit.

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Article Synopsis
  • The study measures how the boron flux in cosmic rays changes with energy and compares it to carbon flux using data from the Calorimetric Electron Telescope (CALET) over approximately 6.4 years.
  • The researchers found a hardening in the boron spectrum beginning at around 200 GeV/n, indicating that boron and carbon have different energy dependences despite the observed similarities at certain transition energies.
  • They also suggest that the B/C ratio, along with their findings, supports recent observations indicating that secondary cosmic rays like boron experience more significant energy hardening than primary ones.
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