NOVELTY - A hydrogen separator for separating hydrogen gas from a source gas, comprises a hydrogen permeable tube having an open first end and a closed second end, where the hydrogen permeable tube is made of a hydrogen permeable material; and a support tube coaxially aligned with the hydrogen permeable tube. A gap space exists between the hydrogen permeable tube and the support tube. The source gas is introduced into the gap space. Hydrogen from the source gas passes through the hydrogen permeable tube from the gap space and is collected.    USE - The inventive separator is used for separating hydrogen gas from a source gas.    ADVANTAGE - The inventive separator uses palladium tubing, and greatly reduces the susceptibility of the palladium tubing to cycle fatigue damage. It optimizes the exposure of gas to palladium surfaces, thus minimizing the need for hydrogen to diffuse through contaminant gases. It enables a large concentration of hydrocarbon gas to pass through palladium conduits without having the hydrocarbons being swept out of the conduits by the flow of gas.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a method of separating hydrogen gas from a source gas, comprising providing the hydrogen permeable tube and the support tube, where the hydrogen permeable tube and the support tube overlap and are coaxially aligned so that the gap space exists between the hydrogen permeable tube and the support tube; and passing the source gas through the gap space between the hydrogen permeable tube and the support tube, where hydrogen from the source gas passes through the hydrogen permeable tube and is separated from the source gas; and    (2) a hydrogen permeable tube assembly for use within a hydrogen separator, including a straight tube having a first end, a second end, an exterior surface and an interior surface that extends between the first end and the second end, where the straight tube is fabricated from a hydrogen permeable material; and an end cap made of a hydrogen impermeable material, where the end cap extends inside the second end of the straight tube and is brazed to the interior surface.    DESCRIPTION OF DRAWING(S) - The figure is a schematic of a hydrogen purification system.    Hydrogen purification system (10)    First collection port (14)    Second waste gas collection port (16)    Supply port (18)