PANDORA project: photo-nuclear reactions below A=60

A. Tamii, L. Pellegri, P. -A. Söderström, D. Allard, S. Goriely, T. Inakura, E. Khan, E. Kido, M. Kimura, E. Litvinova, S. Nagataki, P. von Neumann-Cosel, N. Pietralla, N. Shimizu, N. Tsoneva, Y. Utsuno, S. Adachi, P. Adsley, A. Bahini, D. Balabanski, B. Baret, J. A. C. Bekker, S. D. Binda, E. Boicu, A. Bracco, I. Brandherm, M. Brezeanu, J. W. Brummer, F. Camera, F. C. L. Crespi, R. Dalal, L. M. Donaldson, Y. Fujikawa, T. Furuno, H. Haoning, Y. Honda, A. Gavrilescu, A. Inoue, J. Isaak, H. Jivan, P. M. Jones, S. Jongile, O. Just, T. Kawabata, T. Khumalo, J. Kiener, J. Kleemann, N. Kobayashi, Y. Koshio et al.

Submitted on 7 November 2022, last revised on 18 November 2022


Photo-nuclear reactions of light nuclei below a mass of A=60 are studied experimentally and theoretically by the PANDORA (Photo-Absorption of Nuclei and Decay Observation for Reactions in Astrophysics) project. Two experimental methods, virtual-photon excitation by proton scattering and real-photo absorption by a high-brilliance gamma-ray beam produced by laser Compton scattering, will be applied to measure the photo-absorption cross sections and the decay branching ratio of each decay channel as a function of the photon energy. Several nuclear models, e.g. anti-symmetrized molecular dynamics, mean-field type models, a large-scale shell model, and ab initio models, will be employed to predict the photo-nuclear reactions. The uncertainty in the model predictions will be evaluated from the discrepancies between the model predictions and the experimental data. The data and the predictions will be implemented in a general reaction calculation code TALYS . The results will be applied to the simulation of the photo-disintegration process of ultra-high-energy cosmic rays in inter-galactic propagation.


Subjects: Nuclear Experiment; Astrophysics - High Energy Astrophysical Phenomena; Nuclear Theory


Photo-neutron cross sections, $^{13}{\rm C}(\gamma,xn)$, as a function of the excitation energy (photon-energy). The theoretical cross sections are calculated by the reaction code \talys\ using two models, the Brink-Axel Lorentian (dashed line) and the Goriely's hybrid (solid line). They are plotted in comparison with available experimental data taken from the EXFOR database~\cite{EXFOR}. The L0131~\cite{maeda2006isovector} data (cross marks) were measured with a tagged-photon beam, M0363~\cite{koch1976photoneutron} (diamond) with a Bremsstrahlung photon-beam, and L0048~\cite{jury1979photoneutron} (square) by the positron-annihilation in-flight method. L0131 and M0363 (diamond) are one neutron detection data, while L0048~\cite{jury1979photoneutron} is the integrated cross-section of the $(\gamma,n)$ and $(\gamma,2n)$ channels. The two neutron separation energy in $^{13}{\rm C}$ is $S_{nn}=23.7$ MeV.