Slider bearing for use with an apparatus comprising a vacuum chamber

The invention relates to a slider bearing for use with an apparatus comprising a vacuum chamber (11), comprising: a base plate (20) in contact with the vacuum chamber (11) at one side, said base plate showing a first through-hole (21) in contact with the vacuum chamber (11), a second plate (30), one side of the second plate in contact with the base plate (20), said second plate showing a second through-hole (31), the faces of the base plate and the second plate facing each other being sufficiently smooth to form a non-elastomeric vacuum seal, said base plate (20) and said second plate (30) slidable between a first relative position in which the first through-hole (21) and the second through-hole (31) do not overlap and a second relative position in which the first through-hole and the second through-hole overlap, characterized in that the second plate (30) is a flexible plate, the face of the flexible plate opposite to the base plate is arranged to seal against a cup (50), the cup arranged to hold a sample (1