Determine the origin of the five high-energy events in the mass-A = 230 spectrum

Determine whether the five high-energy events observed in the mass-A = 230 radioactive-beam spectrum originate from cluster emission by $^{230}$Ra or instead from an alternative, unidentified source.

Background

The paper reports five events with energies between 20 and 40 MeV in a mass-separated A=230A = 230 beam measured at ISOLDE. After examining beam contamination, electronic noise, alpha-particle summing, and low-energy fission fragments, the authors identify 230^{230}Ra emitting 22^{22}O as the most likely cluster-emission interpretation.

However, the analytical cluster-emission formulas predict half-lives at least 15 orders of magnitude longer than the experimentally inferred half-life. This substantial discrepancy leaves the cluster-emission interpretation unresolved and motivates determining whether the events have an alternative origin.

References

This discrepancy suggests that the possibility of an alternative origin for the five high-energy events cannot be excluded.

— Cluster emission and its impact on the r-process nucleosynthesis  (2608.24499 - Thomas et al., 25 Aug 2026) in Section 3.1, “Comparison to $A = 230$ spectrum experimental data”