Derivation of Correction Terms to the Eikonal Expansions in the Abrasion-Ablation Model for High Energy Heavy Ion Collisions, S. Bhatt, University of Tennessee, USA − The analytical abrasion-ablation model is widely used for the quantitative predictions of the neutron and light ion spectra from high energy collisions.  The abrasion stage of the current model is based on the Glauber’s multiple scattering theory and applies the small angle approximation which assumes the longitudinal momentum transfer for the scattering amplitude to be small.  However, for reactions with three or more particles in final state the validity of Glauber’s model are not clear.  In this work we have extended the current abrasion model to include higher order terms to the first order eikonal scattering using perturbation approach.  The perturbation approach uses expansion of Fourier Bessel series in the scattering amplitude in terms of Legendre polynomials, thus creating an infinite series.  This expansion eliminates the small angle approximation used in the Glauber-type eikonal approximation and hence extends it to larger angles and low energy regions.   A comparison of this model with two and four correction terms respectively is done with the currently existing model for the derivations of angular distributions and double differential cross-sections for various projectile target data sets.