Photonuclear reaction of ²⁰Ne to alpha particles

The alpha cluster model is a model in which the ⁴He nucleus is regarded as the smallest unit constituting the nucleus. Since ⁴He nuclei are Bose particles, it is theoretically expected that in the condensed matter physics, properties unique to the well-known Bose particle multi-body system also appear in the nucleus of the Fermi particle multi-body system. Currently, such a unique state is considered to be a gas-like alpha cluster state and experimentally verified in the excited state of ¹²C.

In DUBNA, an experiment in which nuclear nuclei such as ²⁰Ne of several GeV was incident on an emulsion detector has been observed in which incident particles decay into a large number of ⁴He in the very forward angels. We thought that this event was caused by the nuclei in the emulsion that the alpha cluster state of ²⁰Ne was excited by Coulomb excitation. Therefore, we conducted experiments to irradiate ²⁰Ne with real photons. Using the electron storage ring of the New SUBARU accelerator facility, laser Compton scattering gamma ray was irradiated to ²⁰Ne gas, and the decay from the excited ²⁰Ne into alpha particles was measured with a TPC detector.