Method for cryogenic cooling of an nmr detection system with the assistance of a container filled with a cryogenic fluid

Abstract

A method for the transmission/reception of RF signals for NMR measurements uses a heat exchanger () for cooling heat sources (), the heat exchanger having a contact element () for thermal connection between a cryogenic fluid and the heat source, is characterized in that the heat exchanger comprises a container having an interior volume Vinto which a first cryogenic fluid Fthat has a liquid component Fand a gaseous component Fflows through an inflow conduit () and from which a second cryogenic fluid Fthat has liquid component Fand a gaseous component Fflows out through an outflow conduit (). The inflow conduit has a flow cross-section Qand a circumference Ufrom which an associated parameter V=4·Q/Uresults, wherein V>10·V, and the outflow conduit has a flow diameter Qwherein Q≥Q. The contact element is in close thermal contact with both the liquid volume component Vof the cryogenic fluid and with the heat source. A device for setting the inflow quantity of the first cryogenic fluid Finto the container is provided that ensures a state F/F>F/Fduring operation. In this way, vibrations due to the cooling process can be largely reduced and the consumption of cryogenic fluid minimized.