First eighteen months of simultaneously measurements of the energy spectrum of CosmicRay induced neutrons on the Pic-du-Midi Observatory and the Concordia Station in Antarctica

• Published in: Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017)
• Main Author: Hubert, Guillaume
• Other Authors: ONERA - The French Aerospace Lab Toulouse, ONERA
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2017
• Subjects: [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; Antarctic; Concordia Station; The Antarctic; Antarc*; Antarctica
• Online Access: https://hal.archives-ouvertes.fr/hal-01890890; https://doi.org/10.22323/1.301.0465

International audience A neutron spectrometer network composed by two high-altitude stations was operated by the French Aerospace Lab. And using Bonner Sphere System extended to high energies. This instrument can measure the neutron spectrum over a wide energy range from meV up to tens of GeV with a short time resolution, allowing to investigate solar flare. Instruments are operated in the Pic-du-Midi (French Pyrenees, +2885m) since May 2011 and, in the framework of the CHINSTRAP project supported by the IPEV (the French Polar Institute) in Concordia station (Antarctica, +3233m) since December 2015, respectively. In this work, first eighteen months of simultaneously measurements of the energy spectrum of indirect-CR are presented and analysed. In addition to the usual analyses (i.e. count rates and fluxes), neutron spectrum and their energetic domain are investigated. Spectrum measurements are coupled with transport modelling including simulation of atmospheric cascades and primary spectra which only depend on the solar modulation potential (i.e. Force-Field Approximation). Thus, a part is devoted to study the solar modulation potentials extracted from the both stations. Results show that is possible to characterize quantitatively the neutron spectrum in the Pic-du-Midi using modelling and cascade neutron measured in Concordia (and reciprocally). Contributions induced by cascade neutrons can be extracted from measurements to deduce the solar potential, allowing to deduce or to enrich indirect-CR specifications for other locations and conditions. An applied case is presented for the Antarctic continent and it compares and to cross-analyses the indirect-CR variations from the neutron spectrum and NMs during 2016.