Test measurement of the <sup>12,13</sup>C (p, p alpha) Reactions for the PANDORA Project

POSTER

Abstract

The PANDORA project plans to investigate photo-nuclear reactions in the mass region below A ∼ 56. The main motivation of this project is to understand the energy loss process of nuclei consisting of ultra-high-energy cosmic rays (UHECRs) in inter-galactic propagation. The origin, acceleration mechanism, and composition of UHECRs are still unknown. However, UHECRs with energies above 1020 eV are observed by large cosmic-ray air-shower observatories such as Pierre Auger and Telescope Array. Analyses of air-shower depth distributions revealed a trend to be heavier in the mass composition between protons and iron at the highest energies.

UHECR nuclei are predicted to primarily lose their energy by emitting particles after photo-nuclear excitation by absorbing a cosmic microwave background (CMB) photon. Therefore, photonuclear reaction cross-sections and decay branching ratios are crucial elements for understanding the energy and mass evolution of UHECRs during inter-galactic propagation.

In the experiment, virtual photon exchange by proton scattering will be used to excite target nuclei and determine the photo-absorption cross-sections covering the giant dipole resonance. The detection of decay particles will extract branching ratios.

Data for the 12,13C (p, p alpha) reactions at 392 MeV were measured in a test experiment in Dec. 2022 and some improvement points were identified.

I will report the status of the experimental setup for a beam time in Oct. 2023.

Presenters

  • Yohei Sasagawa

    • Department of physics, Osaka University

Authors

  • Yohei Sasagawa

    • Department of physics, Osaka University

  • Atsushi Tamii

    • Research Center for Nuclear Physics

  • Shinsuke Ota

    • Research Center for Nuclear Physics, Osaka University
    • RCNP, Osaka University

  • Nobu Kobayashi

    • RCNP
    • Osaka University
    • Research Center for Nuclear Physics, Osaka University
    • RCNP, Osaka University

  • Azusa Inoue

    • RCNP, Osaka University

  • Ryota Iwasaki

    • RCNP, Osaka University

  • Takahiro Kawabata

    • Department of Physics, Osaka University
    • Department of Physics, School of Science, Osaka University
    • Osaka University
    • Depertment of Physics, Osaka University

  • Tatsuya Furuno

    • Department of Physics, Osaka University
    • Department of Physics, School of Science, Osaka University
    • Depertment of Physics, Osaka University

  • Yuya Honda

    • Department of Physics, Osaka University
    • Depertment of Physics, Osaka University

  • Hiroaki Shibakita

    • Department of Physics, Osaka University

  • Yuki FUJIKAWA

    • Department of Physics, School of Science, Kyoto University
    • Department of Physics, Kyoto University

  • Satoshi Adachi

    • CYRIC, Tohoku University
    • CYRIC, Tohoku Universty
    • Cyclotron and Radioisotope Center, Tohoku University
    • Department of Physics, Osaka University
    • Cyclotron and Rareisotope Center, Tohoku University

  • Jacob Bekker

    • Department of Physics, Witwatersrand University

  • Luna Pellegri

    • Department of Physics, Witwatersrand University

  • Retief Neveling

    • iThemba LABS

  • P-A Söderström

    • ELI-NP
    • Extreme Light Infrastructure - Nuclear Physics

  • Andreea Gavrilescu

    • ELI-NP

  • Motoki Murata

    • Research Center for Nuclear Physics, Osaka University
    • RCNP, Osaka University