Progress report of a cryomechanical hybrid vacuum pump prototype

A novel concept of a mechanical vacuum pump is presented and a prototype is described that is capable of operating at a low temperature of 25 K. Since gas density varies inversely with temperature, this pump delivers much higher mass flow rate at low temperature than at room temperature for a given size. Advantages of this concept are reduction in size and weight, when compared to a conventional pump scaled for the same mass flow rate at room temperature. A temperature gradient between the different pumping stages allows optimization of the exhaust pressure. This pump would be a solution for continuous tritium extraction and minimization of the mass inventory for fusion tokomaks fuel cycle control.