Method and apparatus for cooling a load and system comprising corresponding apparatus and load

An apparatus for cooling a load using liquid nitrogen, which is configured to transport the liquid nitrogen in a circuit, to cool the transported liquid nitrogen by indirect exchange of heat with cooled liquid nitrogen, and to expose the transported liquid nitrogen to an exchange of heat with the load, said apparatus comprising:

• an open cooling system (10) designed to cool a first part of the liquid nitrogen by reducing pressure and transporting away nitrogen vapor which forms for cooling the first part of the liquid nitrogen, which part is provided for cooling the liquid nitrogen transported in the circuit, a closed cooling system (20) comprising one or more cooling units for cooling a second part of the liquid nitrogen for cooling the liquid nitrogen that is transported in the circuit, wherein the open cooling system (10) and the closed cooling system (20) are designed to cool a power supply (1) that has a first end and a second end, wherein the open cooling system (10) is arranged on the first end of the power supply (1) and the closed cooling system (20) is arranged on the second end of the power supply (1), and the apparatus is designed to provide cooling power in a first period and a second period, wherein in the first period a smaller amount of a total cooling power is supplied and in the second period a higher amount of the total cooling power is supplied, wherein a first part of the total cooling power is supplied by the open cooling system (10), and a second part of the total cooling power is supplied by the closed cooling system (20), and the first part of the amount of total cooling power can be adjusted to a lower value in the first period than in the second period.