Precise resonance energies measured for energy calibration of particle accelerator using thin silicon–nitride foils

In this work resonance parameters of the 28Si(p,p′γ)28Si (Eγ = 1779 keV) and 14N(p,p′γ)14N (Eγ = 2313 keV) reactions were measured between 3 and 4 MeV proton energies for absolute proton beam energy calibration of particle accelerators. For the measurements commercially available self-supporting thin silicon–nitride films and a HPGe gamma-detector were used which are readily available in most accelerator laboratories. Based on our measurement and on the assessment of literature data, the following resonance energies and widths are recommended: 3100.6 ± 0.9 keV (Γ = 11.9 ± 0.4 keV) and 3338.1 ± 1.0 keV (Γ = 11.0 ± 0.5 keV) in 28Si(p,p′γ)28Si and 3903.1 ± 1.7 keV (Γ = 98 ± 1 keV) and 3991.6 ± 1.1 keV (Γ = 10.8 ± 0.5 keV) in 14N(p,p′γ)14N. In addition to the resonance measurements, absolute thick target yields and gamma-ray angular distributions were measured for the 28Si(p,p′γ)28Si (Eγ = 1779 keV) reaction in the vicinity of Ep = 3.10 and 3.34 MeV for ion beam analysis purposes using a thick silicon wafer target.