Preserving He

Efficient preservation of helium resources at ILL

P. Mendes, S. Baudoin, N. Belkhier, E. Bourgeat-Lami, J.-P. Gonzales, Y. Memphis, E. Lelièvre-Berna, O. Losserand, X. Tonon, S. Turc
Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France

With more than 80 cryostats and cryofurnaces, a dozen of cryomagnets and several dilution refrigerators, the operation of the 42 ILL and CRG instruments requires more than 500 litres of liquid helium per day, i.e. about 13 tons of helium per year. With a recovery efficiency of 95-96%, we reduce the operation costs by about 40%.

The preservation of the gas is the result of a rigorous work performed on a daily basis. The volume of liq- uid helium is weighted before and after its allocation to instruments or laboratories. Gas counters are installed on all the instruments and at strategic places so that we can easily localise an increase of the losses.
In order to monitor the movements of the gas and detect the losses, we have developed an application which reports at any time the amount of helium used and recovered on the instruments, the laboratories and the guide halls. This application collects remotely (Ethernet) the data reported by the gas counters and those entered on mobile data terminals.

We describe the organisation of the recovery system, the accounting software producing automatically monthly and yearly reports and present the mobile data terminal developed for collecting the movements of the gas in real time.