CRYOGENIC COOLING APPARATUS AND METHOD USING A SLEEVE WITH HEAT TRANSFER MEMBER

1 . Cryogenic cooling apparatus comprising:—

a chamber for containing coolant;

a neck which opens into the chamber;

a sleeve located in use within the neck;

a cooling element located exterior to the sleeve; and

wherein the sleeve further comprises a heat transfer member adapted to cause the cooling element to remove heat from the interior of the sleeve through the use of the heat transfer member.

2 . Apparatus according to claim 1 , wherein in use the heat transfer member is adapted to remove heat from an insert positioned within the sleeve by forming at least a first convection current between the heat transfer member and the insert.

3 . Apparatus according to claim 1 or claim 2 , wherein the cooling element removes heat from the heat transfer member by forming at least a second convection current between the cooling element and the heat transfer member.

4 . Apparatus according to any of the preceding claims, wherein the heat transfer member comprises a collar located within the sleeve.

5 . Apparatus according to claim 4 , wherein the heat transfer member comprises a first surface located on the interior of the sleeve and a second surface located on the exterior of the sleeve.

6 . Apparatus according to claim 1 , wherein the cooling element comprises a collar located within the neck.

7 . Apparatus according to claim 6 , wherein the cooling element comprises a first surface located on the interior of the neck and a second surface located exterior to the neck.

8 . Apparatus according to claim 1 , wherein the heat transfer member comprises one or more apertures and wherein the apparatus is adapted to form a third convection current between the cooling element and an insert positioned within the sleeve through the said one or more apertures.

9 . Apparatus according to any of the preceding claims, wherein the heat transfer member is constructed from a material with a high thermal conductivity.

10 . Apparatus according to claim 1 , wherein the sleeve is constructed from a material with a low thermal conductivity.

11 . Apparatus according to any of the preceding claims, wherein the cooling element is constructed from a material with a high thermal conductivity.

12 . Apparatus according to any of the preceding claims, wherein the cooling element is separated from the sleeve by a gap.

13 . Apparatus according to any of the preceding claims, wherein the cooling element is cooled by a pulse tube refrigerator.

14 . Apparatus according to any of the preceding claims, wherein the cooling element has a temperature of about 50 K.

15 . Apparatus according to any of the preceding claims, wherein the coolant is an isotope of helium.

16 . A method of cooling the interior of a cryogenic cooling apparatus, the apparatus comprising:—

a chamber for containing coolant;

a neck which opens into the chamber;

a sleeve located in use within the neck;

a cooling element located exterior to the sleeve; and

wherein the sleeve further comprises a heat transfer member adapted to cause the cooling element to remove heat from the interior of the sleeve through the use of the heat transfer member the method comprising:—

transferring heat from the interior of the sleeve to the heat transfer member by forming at least a first convection current; and

transferring the heat from the heat transfer member to the cooling element.

17 . A method according to claim 16 , wherein at least one convection current transfers the heat from an insert positioned within the sleeve to the cooling element.

18 . A method according to either of claim 16 or 17 , wherein when the heat transfer member comprises one or more apertures, upon either insertion and/or removal of the sleeve from the neck a hinged collar is used to surround the apertures to prevent coolant gas escaping through the apertures.