Some embodiments include an x-ray system, comprising: a structure having a hole having an axially extending wall; and a nozzle disposed in the hole; wherein the nozzle and the axially extending wall form a plurality of axially extending helical fluid channels. Some embodiments include an x-ray system formed by shaping tubing to form a plurality of axially extending helical flutes; and forming a plurality of axially extending helical fluid channels by inserting the shaped tubing into a hole in a structure.