In order to study the atomic structure of surfaces it is essential that they are kept free from contamination for as
long as possible. This necessitates use of an ultra high vacuum (UHV). The image (taken from Caburn-MDC's web site - a leading supplier
of UHV equipment for surface science applications) is of a stainless steel component used in a typical UHV system. Section 3 covers UHV physics and technology.