Time domain analysis of higher order modes induced power dissipation in accelerating cavities

Abstract

We give a semi-analytical method for the calculation of the transient power and energy dissipated in the cavity walls of an accelerating structure due to the excitation of the higher order modes by a sequence of accelerating bunches. We treat the case where more than one bunch is present in the structure at the same time. The dissipated power is evaluated using the Lagrangian formalism and the dissipation function. Both the dissipated power from the transient fields, present when the bunch is inside the cavity, and from the time harmonic fields, present when the bunch has left the cavity, are included in the evaluations. This method is applied to the six-cell elliptic medium beta cavities for the LINAC of the European Spallation Source. The simulations constitute a thorough test of the dissipated power of the design.

Keywords:

• Elliptical cavity
• higher order modes
• LINAC

Notes

No potential conflict of interest was reported by the authors.