The present invention discloses the improvements to a vacuum swing adsorption (VSA) process used for Xe recovery. By only collecting the recovered gas mixture after the initial evacuation of N2 from the adsorbent vessel and void space, the recovered Xe is not diluted by N2 contained in the adsorbent vessel and void space. The concentration of the recovered Xe can by increased (high purity), simultaneously little Xenon is lost. During the initial evacuation of N2, the vessel has been evacuated to a pressure less than 1 atmospheric pressure, for example, from 100 to 1 torr.