“…Theory [5,6,7] predicts that, after a large number of cells (N), the maximum amplitude of the BBU asymptotes to I is the beam current in kA, tr Z is the transverse coupling impedance in Ohms/cm, B is the solenoidal guide field in kG, and indicates an average over the cells. This scaling of BBU growth has been experimentally validated [3,8,4,9], and is unmistakable in computer simulations based on models of beam interaction with the cavities [10].…”