LAUSR

A study of the NICA collider dynamical aperture (DA) using the MADX code has shown that, in the chosen working point (Qx,Qy ∼ 9,43), the DA sharply decreases when taking into account the fringe fields of the quadrupole lenses and dipole magnets. An analytical theory is developed to calculating the strength of resonances generated by the fringe fields of the quadrupole lenses in a circular machine. It is shown that the formulae derived for these parameters have a general character and do not depend on the lens design. The codes for a numerical calculation of the anharmonicity coefficients and resonance strength in the NICA collider are written. The method is developed to estimate the resonance strength by using the numerical simulation of the trajectories with the help of the MADX code. For the NICA collider structure, the results of the analytical calculation of the resonance strength for a chosen resonance coincide with the results obtained using the MADX code with a satisfactory accuracy.