Reese Puckett and Ganapati Myneni*

Pfeiffer Vacuum

Nashua, NH 03063-1988

Sputter ion pumps and non-evaporable getter pumps are popular choices for routinely achieving UHV. However, dry turbo pumps have traditionally served as initial roughing pumps for achieving hydrocarbon free UHV/XHV environments. With the development of wide range turbo molecular pumps, one is able to obtain high compression ratios for the light gases such as helium and hydrogen. As a result the wide range turbo pumps are capable of achieving UHV/XHV on their own. Further, the turbo pumps do not have the possibility of releasing previously pumped gases back into the vacuum system, unlike the ion and non-evaporable getter pumps.

In this paper, we will present the details of a simple UHV/XHV system with extreme sensitivity helium leak detection and cross calibration capability.