On the utility of fluid flow models in the design of heat exchangers for cooling 4th generation X ray optics

As the Diamond Light source moves towards upgrading to a 4th generation source, increasing x-ray powers and reduced focal sizes will require improved cryogenic cooling to ensure that the projected new levels of brilliance are achieved. This will create a greater demand for LN2, if current systems are maintained, laying a greater economic demand on the facility. As in most cases, new designs are tested using thermal-structural finite element simulation, neglecting the contribution of fluid flow. This leaves us without information about the effect of the fluid on the surface of the crystal, along with the efficiency of the flow itself. This results in under optimised cooling systems, leaving cooling capabilities of the system reduced, increasing the consumption of LN2. This paper presents a full fluid-structure-thermal model, showing the full effects of the flow of liquid nitrogen on the system. This paper will discuss this model in comparison to a conventional thermal-structure model.