AGS, a computer code for uncertainty propagation in time-of-flight cross section data

In this paper, the AGS (Analysis of Generic TOF-Spectra) system is described. The AGS system has been developed to transform count rate spectra of time of flight measurements in an efficient and convenient way into experimental observables, which can be used as input for nuclear reaction model fitting codes. It is explained how the covariance matrix can be broken down in an uncorrelated and a correlated part. The latter may in turn be expressed as the product of a rectangular matrix with its own transpose. We describe how this representation is used to propagate uncertainties starting from uncorrelated uncertainties due to counting statistics and to store the full covariance information with reduced storage space. (authors)