A method and apparatus for providing an operating system abstraction interface for a set-top television terminal used within a broadband environment. The reactor encloses a core having a plurality of fuel rods. As the pressures within the valve start to balance, the restrictor device opens, allowing full pilot flow to hold the valve in position. The plastic sheath results in a dimensionally stable pocket, in which the permanent magnet can subsequently be inserted. The surface of the electron emission layer is preferably composed of alkaline earth metals such as barium or cesium.