Technology readiness assessment of graphene thermal straps for the WFI instrument

The Camera Head of the Wide Field Imager (WFI), which is to fly on the X-ray telescope NewAthena, is a compact sub-system requiring the integration of three separate temperature regions. One will be the environment temperature of the instruments support structure. The other two temperature environments are governed by the requirements of the detector front-end electronics and the sensor itself. Due to the limited space available and high heat fluxes that the system needs to remove at temperatures as low as 160 K, graphene thermal straps are used. Although already in use in some space applications, space qualified graphene thermal straps are not available on the market, therefore a qualification program, specific for the environmental conditions and requirements of the WFI system, has been carried out. The thermal straps are tested for their thermal performance, structural stability and particle shedding, thermally cycled and outgassed.