Modelling of the Thermo-Mechanical Behavior of the Two-Beam Module for the Compact Linear Collider

To fulfil the mechanical requirements set by the luminosity goals of the compact linear collider, the 2-m long two-beam modules, the shortest repetitive elements in the main linear accelerator, have to be controlled at micrometer level. At the same time these modules are exposed to high power dissipation that varies while the accelerator is ramped up to nominal power and when the mode of the accelerator operation is modified. These variations will give rise to inevitable temperature transients driving mechanical distortions in and between different module components. Therefore, the thermo-mechanical behaviour of the module is of a high importance. This thesis describes a finite element method model for the two-beam compact linear collider module. The components are described in detail compared to earlier models, which should result in a realistic description of the module. Due to the complexity of the modules, the modelling is divided into several phases from geometrical simplification and modification to the creation of appropriate cooling environment and finally towards full-scale thermo-mechanical behavior of the accelerator in its primary operation modes. The thermal and structural results for the new module configuration are presented and the thermo-mechanical behavior of the module in its primary operation modes is discussed. These results will be compared with the forthcoming laboratory measurements. Improved understanding of the module’s thermo-mechanical behavior and its simulation model can then be propagated to the following module generations using the model presented in this thesis as a baseline.