Modeling energy dependent nuclear reaction probabilities from pointwise measurements including full covariance information

For the design of large and highly complex facilities - like, the international project ITER (http://www.iter.org/) - reliable basic data with well established covariance information (uncertainties, correlations) are indispensable. Procedures to attain the requirements by means of a Bayesian generalized least squares method and recent approaches using theoretical nuclear reaction codes in combination with Monte Carlo techniques will be discussed and results compared. Particular emphasis is given to the procedures of constructing covariance matrices for the experimental data sets as this determines the quality of the result.