Outgassing Performance Research on CuCrZr

The outgassing rate of CuCrZr was measured by switching between two pumping path method(SPP).For CuCrZr baked at 150℃for 24 hours,the measured outgassing rate is 2.89×10^-10Pa·L·s^-1·cm^-2(nitrogen equivalency).When the baking temperature is raised to 250℃,the outgassing rate decreases about an order ofmagnitude.The outgassing rate of CuCrZr,degassed in a vacuum furnace at 400℃ for 24 hours,is as low as 1.64×10^-11Pa·L·s^-1·cm^-2after baking at 150℃for 24 hours.Further increasing the baking temperature,the outgassingrate has little change.X-ray photoelectron spectroscopy was used to analyze the surface composition of CuCrZr atdifferent temperatures.At 250℃,the Cu oxide film on the CuCrZr surface is almost completely decomposed.Whenthe temperature goes up to 400℃,Cr atoms in the CuCrZr alloy are precipitated to the surface.The Cr atoms remain on the surface when the temperature subsequently drops down to room temperature.These results indicate thatthe variation in the oxide film composition of the CuCrZr surface causes the difference in the outgassing rate.