MODELING THE HEAVY-ION UPSET CROSS-SECTION

The standard Rectangular Parallelepiped (RPP) construct is used to der ive a closed form expression for, ($) over bar sigma(theta, phi, L) th e directional-spectral heavy ion upset cross section, This is an expec ted value model obtained by integrating the point-value cross section model, sigma(theta, phi, L, E), also developed here, with the Weibull density function, f(E), assumed to govern the stochastic behavior of t he upset threshold energy, E. A comparison of ($) over bar sigma(theta , phi, L) with experimental data show good agreement, lending strong c redibility to the hypothesis that E-randomness is responsible for the shape of the upset cross section curve, The expected value model is us ed as the basis for a new, rigorous mathematical formulation of the ef fective cross section concept, The generalized formulation unifies pre vious corrections to the inverse cosine scaling, collapsing to Peterse n's correction, [cos theta - (h/l) sin theta](-1), near threshold and Sexton's, [cos theta + (h/l) sin theta](-1), near saturation, The expe cted value cross section model therefore has useful applications in bo th upset rate prediction and test data analysis.