Abstract: A cryogenic system includes a superconducting magnet (20) in a reservoir of liquid helium (LH). Helium vapor (VH) rises and contacts a recondenser surface (50, 50?, 50?) on which the helium vapor (VH) condenses into liquid helium and flows by gravity off a lower edge of the recondenser surface. A plurality of fins (52) extend from the recondenser surface or a plurality of grooves (52?, 52?) are cut into the recondenser surface to disrupt the film thickness and to provide a path by which droplets of the liquid helium leave the recondenser surface without travelling a full vertical length of the recondenser (30).

Abstract: A cryogenic system includes a superconducting magnet (20) in a reservoir of liquid helium (LH). Helium vapor (VH) rises and contacts a recondenser surface (50, 50?, 50?) on which the helium vapor (VH) condenses into liquid helium and flows by gravity off a lower edge of the recondenser surface. A plurality of fins (52) extend from the recondenser surface or a plurality of grooves (52?, 52?) are cut into the recondenser surface to disrupt the film thickness and to provide a path by which droplets of the liquid helium leave the recondenser surface without travelling a full vertical length of the recondenser (30).

Abstract: A method can be used to perform an operation on a system that includes an assembly and a vessel that includes a wall and a thermal shield. The method can include breaking a thermal connection between the assembly and the thermal shield, separating the assembly and a surface within the vessel from each other, or any combination thereof. The method can also include changing a pressure with the vessel to be closer to atmospheric pressure, heating the assembly, or any combination thereof. In one embodiment, the method can be performed while keeping a cryogenic region substantially sealed, keeping a superconducting magnet energized, or a combination thereof. In a particular embodiment, the method can be used when servicing the assembly, such as a cryocooler.