Abstract:
A device for transporting heat between two temperature levels which are situated below 1*K, provided with a mixing chamber having an inlet duct for the supply of a medium flow consisting mainly of 3He. The mixing chamber is connected, via a connection duct which is in heat-exchange with the inlet duct, to an evaporation reservoir. The mixing chamber, the connection duct and the evaporation reservoir contain a mixture of 4He and 3He during operation. The evaporation reservoir is provided with an outlet for mainly 3He in the vapour phase, and the device furthermore comprises at least one superleak, one side of which opens into and near the bottom of the evaporation reservoir. Its other side communicates with a space provided with a heating device, the said space communicating, via a narrow duct and a cooler, with a duct in which a number of superleaks are arranged. Between the super-leaks heat-exchanging chambers are arranged which exchange heat with the connection duct and the inlet duct. The other end of this inlet duct opens into the upper part of a second mixing chamber. The first and the second mixing chamber are interconnected by a further connection duct which opens into the lower part of the second and into the upper part of the first mixing chamber.
Abstract:
A device for cooling to temperatures lower than that of the lambda -point of helium, in which some high-pressure helium, after being cooled, expands to low-pressure and flows back to the compression device, and the remainder of the He is cooled to below its lambda -temperature forming superfluid He4 that flows through a superleak, and normal He4, and a vortex tube for communicating.
Abstract:
A method of manufacturing a heat exchanger for exchanging heat between helium flows in a temperature range below 2K, comprising two end plates having inlet and outlet apertures, and a stack of very thin foils arranged between the end plates with passageways that extend transverse to the planes of the foils and separate ducts in the planes of the foils which communicate with the passageways. During manufacture the foils are attached with supports provided between foils, which supports are removed by means of a rinsing liquid after the foils have been soldered to each other.