PUMPING DOWN CHARACTERISTICS OF LAB6 AND TIN-COATED VACUUM VESSELS PREPARED BY MAGNETRON SPUTTERING

Lanthanum hexaboride was coated on the wall surface of the vacuum vess el by magnetron sputtering, and the characteristics of pumping down of the coated vessel were investigated by comparing with those of the ti tanium nitride coated vacuum vessel. Right after the sputter depositio n, both vacuum vessels were evacuated in the same way and the effectiv e pumping speed of those surfaces was estimated to be about 4 m(3)/(m( 2)s) for water vapor. These thin films also formed the low outgassing surface, and consequently, after the exposure of the coated vessel to air, the pressure of the vessel decreased by less than 1/3 of that bef ore coating. The outgassing rate of lanthanum hexaboride coated surfac e was abo ut five times larger than that of the titanium nitride coate d surface at a time after 100 min from the start of evacuation. The XP S measurement showed that much oxygen was used in both films. Copyrigh t (C) 1996 Elsevier Science Ltd.