McXtrace - An X-ray ray-trace simulation package

1.3  Component coordinate system

All mentioning of component geometry refer to the local coordinate system of the individual component. The axis convention is so that the \(z\) axis is along the photon propagation axis, the \(y\) axis is vertical up, and the \(x\) axis points left when looking along the \(z\)-axis, completing a right-handed coordinate system. Most components ’position’ (as specified in the instrument description with the AT keyword) corresponds to their volume centre. The mirrors are an important counterexmaple. In this case the ’position’ is the centre of the mirror surface

Components are not necessarily designed to overlap. This may lead to loss of rays. Warnings will be issued during simulation if sections of the instrument are not reached by any xrays, or if a significant number of xrays are removed. This is usually the sign of either overlapping components or low intensity.