PI: Andreas Best/Alba Formicola


Astrophysical Motivation

The reaction 13C(α,n)16O is the main neutron source for the astrophysical s process, which responsible for the production of about half of the heavy elements in the Universe. Knowledge of its cross section in the relevant energy window (T = 90 MK, E ~= 190 keV) is of crucial importance as input for astrophysical models of the s process.


Experimental Aims

Aim of the experiment at LUNA 400 is the measurement of the cross section at energies directly in the Gamow window, where so far there only exist indirect data.


Experimental setup

The experiment has been performed at the solid target station, using enriched 13C evaporated on tantalum backings. The detector consists of low-background 3He counters embedded in a moderating polyethylene matrix. Digital DAQ is used for pulse-shape analysis to further suppress the intrinsic detector background.



  • Direct Measurement of the 13C(α,n)16O Cross Section into the s-Process Gamow Peak

                Physical Review Letters 127, 152701 (2021)

  • A new approach to monitor 13C-targets degradation in situ for 13C(α,n)16O cross-section measurements at LUNA

European Physical Journal A 56 (2020) 75


  • Characterization of the new LUNA neutron detector array for the measurement of the 13C(α,n)16O reaction

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 994 (2021) 165081