Abstract
We present a room-temperature Extreme High Vacuum (XHV) system engineered to support the long-duration operation of a trapped-ion quantum processor. Background-gas collisions impose limitations on trapped-ion performance and scalability by interrupting algorithmic execution and, in some cases, ejecting ions from the trap. Using molecular-flow simulations, we optimize the chamber geometry, conductance pathways, and pumping configuration to maximize the effective pumping speed at the ion location. We perform high-temperature heat treatment of stainless steel vacuum components to achieve the desired outgassing rate, guided by quantitative relations of bulk diffusive processes, allowing us to reduce the H₂ outgassing load to the 10⁻¹⁵mbarls⁻¹cm⁻² level. The final pressure in our chamber, measured by a hot cathode gauge, is 1.5×10⁻¹²mbar, corresponding to the gauge's measurement limit. We measure the local pressure at the ion location by observing collision-induced reordering events in a long ion chain of mixed-isotope Yb⁺. From the observed reordering frequency, we extract the average interval between collisions to be (1.9 ± 0.1)hrs/ion. This corresponds to a local pressure of (3.9 ± 0.3)×10⁻¹²mbar at the ion location, assuming that all collisions arise from background H₂ molecules at room temperature. Our demonstration extends the continuous operation time of a quantum processor while maintaining the simplicity of a room-temperature system that does not require cryogenic apparatus.