Methods and apparatus for filling superconductive magnets

1. A method for filling a magnet comprising feeding gaseous helium to a container of liquefied helium; feeding liquefied helium to said magnet; measuring a flow rate of said gaseous helium from said container and measuring a pressure of said gaseous helium in said container; and stopping flow of said liquefied helium when the measured pressure reaches a peak value and begins to drop.

2. The method as claimed in claim 1 wherein said container is a dewar.

3. The method as claimed in claim 2 wherein said gaseous helium is fed to the top of said dewar.

4. The method as claimed in claim 2 wherein said measured pressure is measured in said dewar.

5. The method as claimed in claim 1 wherein the flow of said liquefied helium is controlled by the flow of said gaseous helium.

6. The method as claimed in claim 1 wherein the flow of said liquefied helium is stopped by stopping the flow of gaseous helium.

7. The method as claimed in claim 1 wherein said magnet is a superconductive magnet.

8. The method as claimed in claim 1 wherein the flow of said liquefied helium is measured with a flowmeter.

9. The method as claimed in claim 1 wherein said peak pressure is measured via a control unit.

10. A method for stopping a filling process comprising feeding gaseous helium to a container of liquefied helium; feeding liquefied helium to a magnet; measuring a flow rate of said gaseous helium; measuring a pressure of said gaseous helium in the dewar; and stopping flow of said liquefied helium when said measured pressure reaches a peak value and begins to drop.

11. The method as claimed in claim 10 wherein said container is a dewar.

12. The method as claimed in claim 10 wherein said gaseous helium is fed to the top of said dewar.

13. The method as claimed in claim 10 wherein said measured pressure is measured in said dewar.

14. The method as claimed in claim 10 wherein the flow of said liquefied helium is controlled by the flow of said gaseous helium.

15. The method as claimed in claim 10 wherein the flow of said liquefied helium is stopped by stopping the flow of gaseous helium.

16. The method as claimed in claim 10 wherein said magnet is a superconductive magnet.

17. The method as claimed in claim 10 wherein the flow of said liquefied helium is measured with a flowmeter.

18. The method as claimed in claim 10 wherein said peak pressure is measured via a control unit.

19. A method for detecting a slow transfer of liquid helium from a dewar to a cryostat of a super conductive magnet comprising feeding gaseous helium to a container of liquefied helium; feeding liquefied helium to said magnet; measuring a flow rate of said gaseous helium from said container and measuring the amount of liquefied helium pushed out of said container; and stopping the flow of said gaseous helium when the ratio of the flow rate of the gaseous helium to the amount of liquefied helium pushed out of said container is different than 6 or 7 to 1.

20. The method as claimed in claim 19 wherein said container is a dewar.

21. The method as claimed in claim 20 wherein said gaseous helium is fed to the top of said dewar.

22. The method as claimed in claim 20 wherein said measured pressure is measured in said dewar.

23. The method as claimed in claim 19 wherein the flow of said liquefied helium is controlled by the flow of said gaseous helium.

24. The method as claimed in claim 19 wherein the flow of said liquefied helium is stopped by stopping the flow of gaseous helium.

25. The method as claimed in claim 19 wherein said magnet is a superconductive magnet.

26. The method as claimed in claim 19 wherein the flow of said liquefied helium is measured with a flowmeter.

27. The method as claimed in claim 19 wherein said different ratio is less than 6 or 7 to 1.