An x-ray source can include an x-ray tube, and a heat sink for removal of heat from the x-ray tube. The heat sink can be thermally coupled to the anode and can extend away from the anode along a heat sink longitudinal axis. The heat sink can have a base and a fin extending from the base. The base can have a greater thickness nearer the anode, and a reduced thickness along the heat sink longitudinal axis to a smaller thickness farther from the anode.