Cryostat configuration with cryocooler and gas gap heat transfer device

Abstract

A cryostat configuration for keeping liquid helium comprises an outer jacket (1) surrounding a helium container (2) connected at at least two suspension tubes (3) to the outer jacket (1), and with a neck tube (4) whose upper warm end (5) is connected to the outer jacket (1) and whose lower cold end (6) is connected to the helium container (2) and into which a multi-stage cold head of a cryocooler (7) is installed, wherein the outer jacket (1), the helium container (2), the suspension tubes (3) and the neck tube (4) delimit an evacuated space, and the helium container (2) is surrounded by at least one radiation shield (8) which is connected in a heat-conducting fashion to the suspension tubes (3) and also to a contact surface (9) on the neck tube (4) of the helium container (2). The cryostat configuration is characterized by a gas gap (13) between one or more cold stages of the cold head (7) and one or more contact surfaces (9) in the neck tube (4) which are each connected in a heat-conducting manner to a radiation shield (8) via a fixed, rigid or flexible thermal bridge (12), heat being transferred through the gas gap (13) from the respective radiation shield (8) to the corresponding cold stage of the cold head (7). A cryostat configuration of this type ensures that no vibrations of the cold head (7) stages pass detectably into the cryostat configuration, wherein the quality of the thermal connection between the cold head (7) and the radiation shield(s) (8) is nevertheless sufficient.

Description

[0001] This application claims Paris Convention priority of DE 10 2004 034 729.8 filed Jul. 17, 2004 the complete disclosure of which is hereby incorporated by reference. BACKGROUND OF THE INVENTION

[0002] The invention concerns a cryostat configuration for keeping liquid helium, comprising an outer jacket and a helium container installed therein, wherein the helium container is connected to the outer jacket via at least two suspension tubes, and with a neck tube whose upper warm end is connected to the outer jacket and whose lower cold end is connected to the helium container, as well as a multi-stage cold head of a cryocooler, wherein the outer jacket, the helium container, the suspension tubes and the neck tube delimit an evacuated space, and wherein the helium container is surrounded by at least one radiation shield which is connected in a thermally conducting fashion to the suspension tubes and to a contact surface on the neck tube of the helium container.

[0003] One possibilit...

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