Wu, G. JACoW Geneva, Switzerland 978-3-95450-178-6 10.18429/JACoW-SRF2015-THBA06 English 1043-1048 THBA06 cryomodule cavity cryogenics shielding linac Contribution to a conference proceedings 2015 2015-12 http://dx.doi.org/10.18429/JACoW-SRF2015-THBA06 http://srf2015.vrws.de/papers/thba06.pdf Maintaining very high cavity Q0 in linac applications creates new challenges for cryomodule design. Magnetic shielding from both external fields and internal fields is required and its importance to thermal gradients during Tc transition is now emerging. This presentation will describe the design challenges and possible mitigation strategies with examples from various applications or laboratories including FRIB, LCLS-II, PIP-II, Cornell University and KEK.