An apparatus (100, 200), comprising: a superconducting magnet including one or more electrically conductive coils; one or more gravity-fed cooling tubes configured to have disposed and circulating therein a first cryogenic fluid in the form of gaseous helium for cooling the superconducting magnet, wherein a lower end of the one or more gravity-fed cooling tubes is thermally connected to the one or more electrically conductive coils of the superconducting magnet; a cryocooler, wherein the cryocooler has a first stage element and a second stage element; and a first heat exchanger configured to have stored therein a volume of a second cryogenic fluid which includes liquid helium or liquid and gaseous helium, wherein the first heat exchanger is thermally connected to an upper end of the one or more gravity-fed cooling tubes on the one hand and wherein the first heat exchanger is thermally connected to the second stage element of the cryocooler via a cooling loop on the other hand, in order to transfer heat from the one or more gravity-fed cooling tubes to the cryocooler; a storage device having an input connected to the first heat exchanger and configured to receive and store a boiled-off gas from the first heat exchanger; and a second heat exchanger thermally connected both to the storage device and to the first stage element of the cryocooler in order to transfer heat from the storage device to the first stage element of the cryocooler; wherein the one or more gravity-fed cooling tubes and the first heat exchanger are configured such that the second cryogenic fluid is physically isolated to be separate from the first cryogenic fluid, thereby enabling during operation of the apparatus that super-cold helium gas of the first cryogenic fluid circulating in the one or more gravity-fed cooling tubes is cooled by an evaporation of the liquid helium of the second cryogenic fluid which is contained in the first heat exchanger, wherein the evaporated helium vapor from the first heat exchanger is in turn condensed by the second stage element of the cryocooler and liquid helium is returned to the first heat exchanger via the cooling loop. a superconducting magnet including one or more electrically conductive coils; one or more gravity-fed cooling tubes configured to have disposed and circulating therein a first cryogenic fluid in the form of gaseous helium for cooling the superconducting magnet, wherein a lower end of the one or more gravity-fed cooling tubes is thermally connected to the one or more electrically conductive coils of the superconducting magnet; a cryocooler, wherein the cryocooler has a first stage element and a second stage element; and a first heat exchanger configured to have stored therein a volume of a second cryogenic fluid which includes liquid helium or liquid and gaseous helium, wherein the first heat exchanger is thermally connected to an upper end of the one or more gravity-fed cooling tubes on the one hand and wherein the first heat exchanger is thermally connected to the second stage element of the cryocooler via a cooling loop on the other hand, in order to transfer heat from the one or more gravity-fed cooling tubes to the cryocooler; a storage device having an input connected to the first heat exchanger and configured to receive and store a boiled-off gas from the first heat exchanger; and a second heat exchanger thermally connected both to the storage device and to the first stage element of the cryocooler in order to transfer heat from the storage device to the first stage element of the cryocooler; wherein the one or more gravity-fed cooling tubes and the first heat exchanger are configured such that the second cryogenic fluid is physically isolated to be separate from the first cryogenic fluid, thereby enabling during operation of the apparatus that super-cold helium gas of the first cryogenic fluid circulating in the one or more gravity-fed cooling tubes is cooled by an evaporation of the liquid helium of the second cryogenic fluid which is contained in the first heat exchanger, wherein the evaporated helium vapor from the first heat exchanger is in turn condensed by the second stage element of the cryocooler and liquid helium is returned to the first heat exchanger via the cooling loop.