Calibration of a Van de Graaf accelerator and determination of the threshold of the reaction 45Sc(p,n)45Ti using a covariance analysis

The resonances of the ²⁷Al(p, γ)²⁸Si reaction are used to determine the relation between the proton energy and the frequency of a nuclear magnetic resonance (NMR) meter controlling the magnetic induction of a 90° bending magnet used for proton energy analysis.The experimental results and their covariance matrix have been used to obtain a calibration function by a least-squares fit. In addition the threshold and the Q value of the reaction ⁴⁵Sc(p, n)⁴⁵Ti have been determined including all uncertainties and correlations in the analysis.