An ion transfer system includes an ion source coupled to an ion inlet; an ion transfer tube assembly including a concentric ion transfer tube with a porous material that is permeable to a gas, the concentric ion transfer tube coupled to the ion inlet and the ion source, where a first gas that includes an ion stream flows through the concentric ion transfer tube; and a concentric gas tube, the concentric ion transfer tube disposed within the concentric gas tube, where a second gas flows between the concentric ion transfer tube and the concentric gas tube; an ion detection device coupled to a capillary tube that is coupled to the concentric ion transfer tube, where the capillary tube transports the ion stream to the ion detection device; and a pump coupled to at least one of the concentric ion transfer tube or the concentric gas tube.
