Sample manipulator employing a gas-thermal switch designed for high pressure experiments in an ultrahigh vacuum apparatus

Abstract

A sample manipulator with a gas-thermal switch was designed for high pressure surface science experiments in an ultrahigh vacuum (UHV) apparatus. The gas-thermal switch coupled the sample mount to the cryostat using helium gas. When helium gas was present and the thermal switch was on, the cooling time constant was τ∼2.6 min. When the helium gas was evacuated, the sample mount was isolated and could be easily warmed to room temperature in ∼5 min using a small ceramic heater. The sample manipulator was built to be part of an internal high pressure chamber. The internal high pressure chamber could obtain pressures as high as 100 Torr with only small pressure excursions of ΔP≊1–2×10−10 Torr in the UHV chamber. Recovery back to UHV conditions occurred only minutes after high pressure experiments with gases or condensable materials such as H2O. This note details the rationale and mechanical design of this sample manipulator with a gas-thermal switch for high pressure experiments in an UHV apparatus.