  In the design of electromagnetic devices the accurate representation of the
geometry plays a crucial role in determining the device performance. For
accelerator cavities, in particular, controlling the frequencies of the
eigenmodes is important in order to guarantee the synchronization between the
electromagnetic field and the accelerated particles. The main interest of this
work is in the evaluation of eigenmode sensitivities with respect to
geometrical changes using Monte Carlo simulations and stochastic collocation.
The choice of an IGA approach for the spatial discretization allows for an
exact handling of the domains and their deformations, guaranteeing, at the same
time, accurate and highly regular solutions.
