Performance of fountain effect pumps with different HeII flow loops

Operational characteristics of a fountain effect pump in a HeII flow loop have been experimentally investigated. Relations between a HeII mass flow rate in the loop and a supplied heat to the pump were measured with different dimensions of the porous plug and the tubes which make up the loop. It is confirmed that the supplied heat can be used effectively to drive HeII when appropriate sizes of the plug and the tubes at the inlet and outlet of the pump are chosen. The tube at the inlet of the plug is required to remove most of the supplied heat and to suppress an increase of HeII temperature at the inlet and outlet of the plug. The tube at the outlet of the plug is required to restrict the heat leakage to the downstream of the flow.