Cooling device for a super conductor and super conducting synchronous machine

A cooling device for a superconductor, comprising:

• a cooling circuit for a coolant, the coolant being liquefied in a cold head with a condenser being conducted to the superconductor to be cooled, and being returned to the condenser in a gaseous form, wherein a pressure generated by a component of the coolant, evaporated by way of a heat source, is used to convey the coolant from the condenser to the superconductor, and wherein the heat source is either
• a heating device, operable cyclically, wherein a ratio of an operating phase of the heating device to a non-operating phase of the heating device is greater than 40%, and/or heat output during the operating phase is less than double the cold head output, or
• a connection to a gas, coupled by way of a thermal bridge, is used as the heat source, a temperature of the gas being higher than a boiling temperature of the coolant.