摘要 |
An apparatus is disclosed. The apparatus includes a compartment for containing a high vacuum environment. The compartment is partly defined by and/or includes a surface that has a subsurface that includes a first zone and a second zone. The second zone is located between the first zone and the surface. The first zone includes a metal or alloy that has a composition which differs from stainless steel. Diffusion is more difficult in the second zone than in the first zone, so that gaseous molecules are inhibited from escaping from the subsurface into the high vacuum environment. |