Articles techniques et présentations

Project X is a proposed proton accelerator complex at Fermilab. The CW LINAC is based on five types of resonators operating at three frequencies: half-wave, spoke, and elliptical. The low beam current for the CW operation of Project X requires cavities to operate at a high loaded Q and, thus, narrow bandwidth. Therefore, it requires optimal mechanical design of the cavities to minimize the sensitivity to microphonics df/dP. In this paper we present the COMSOL Multiphysics® algorithms developed for the evaluation of operating frequency shifts due both to fluctuations in the helium pressure and to mechanical resonances. We conclude that modern cryogenic systems achieve rms pressure stabilities of ~0.2 mbar.