New SC Algorithm for MAD-X

MAD-X allows to simulate space-charge effects by approximating the macro-particle ensemble with a Gaussian distribution and using analytic formulas for calculation of the space-charge kick at locations which should be chosen in advance e.g. with V. Kapin's external code. The new MAD-X version features two innovations: a symplectic three-dimensional space-charge kick and Gaussian fit of particle distribution which - in principle - does not require a linearly stable closed optics to exist thus permitting simulations studies of the parametric resonance stopband crossing. It also allows for non stationary distribution so that envelope resonances can be simulated.