Direct Measurement of the Astrophysical 19F(p,αγ)16O Reaction in the Deepest Operational Underground Laboratory

Fluorine is one of the most interesting elements in nuclear astrophysics, where the F-19(p, alpha gamma)O-16 reaction is of crucial importance for Galactic F-19 abundances and CNO cycle loss in first generation Population III stars. As a day-one campaign at the Jinping Underground Nuclear Astrophysics experimental facility, we report direct measurements of the essential F-19(p, alpha gamma)O-16 reaction channel. The gamma-ray yields were measured over E-c.m. = 72.4-344 keV, covering the Gamow window; our energy of 72.4 keV is unprecedentedly low, reported here for the first time. The experiment was performed under the extremely low cosmic-rayinduced background environment of the China JinPing Underground Laboratory, one of the deepest underground laboratories in the world. The present low-energy S factors deviate significantly from previous theoretical predictions, and the uncertainties are significantly reduced. The thermonuclear F-19(p, alpha gamma)O-16 reaction rate has been determined directly at the relevant astrophysical energies.

Automated summary

Fluorine is considered one of the most interesting elements in nuclear astrophysics, and the direct measurements of the F-19(p, alpha gamma)O-16 reaction channel have provided new insights into the reaction rate at relevant astrophysical energies. The experiment conducted at the Jinping Underground Nuclear Astrophysics facility revealed deviations from previous theoretical predictions in low-energy S factors and significantly reduced uncertainties in the data. This study highlights the importance of experimental data in refining our understanding of nuclear astrophysical processes.