Gamma radiation spectroscopy and the 12C(α,γ)16O reaction with DRAGON
The astrophysically important 12C(α,γ)16O reaction was recently re-enacted at TRIUMF using DRAGON. In this reaction a 12C nuclei fuses with an alpha particle to form 16O. Gamma rays are produced during the 16O decay, and these were detected by an array of 30 hexagonal BGO scintillation detectors. The purpose of this project was to devise a method of identifying and quantifying the discrete components of the gamma radiation using the resulting gamma spectra. The devised method involves identifying potential 16O decay paths and the discrete set of gamma energies associated with these paths, generating detector response functions for gamma radiation of these energies, and fitting a linear combination of these response functions to the experimental spectra. The fit coefficients represent the relative strengths of the contributions of each discrete component to the total spectrum. The method was tested on data taken at the 10.356 MeV resonance, at which 16O is known to decay solely through the 6.917 MeV state. Knowing this, two potential decay paths were assumed, these being cascade decay through the 6.917 MeV and decays through closely spaced states. The test was not successful, and the conclusion is that the method is very sensitive to detector gains and, lacking more accurate information about these gains, the devised methos cannot be used to distinguish between gammas so close in energy. The next step in this project must be an effort to better determine detector gains.
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