SLAC National Accelerator Laboratory uses massive quantities of aluminum foil to perform &quot;bake out&quot; of their equipment. In a typical bake out, the equipment is blanketed in foil, wrapped with electrical heat tape, and then covered in foil again. Heat tape is used to heat the metal chamber just enough to loosen any residues that could cause trouble. The aluminum foil helps spread the heat evenly. | Photo of SLAC 