He Recovery Upgrade

S. Baudoin, N. Belkhier, J. Gonthier, J.-P. Gonzales, E. Lelièvre-Berna, P. Martin, P. Mendes and S. Turc
Institut Laue Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France

With more than 80 cryostats, 12 cryomagnets and several dilution refrigerators, the operation of the +40 ILL instruments requires about 500 litres of liquid helium per day. The cost of helium increases at a rate of ≈10%/year and hopefully less than 5% of the annual consumption of 10-13 tons are lost. We present an upgrade of our He recovery system that simplifies its operation and should help us to maintain its high efficiency. Of course, this project supplements the essential maintenance work of the pumps.

We have installed counters at strategic locations to speed up the localisation of leaks. Mass spectrometer connectors were also added at the same locations to identify equipment polluting the recovery line. The 30-year old PLCs of the compressed He circuit were replaced with redundant PLCs able to decide if the compressors must be operated in parallel, to switch automatically to the most appropriate water-cooling circuit and to report alarms to the team and the reactor control room.

A few years ago, we developed an application for collecting the volumes of liquid and helium gas used by the instruments and the laboratories of the ILL. Today, this application also takes into account the volumes returned by the ESRF and the IBS, produces automatically monthly and yearly reports and displays remotely the real-time status of the He compressors. The data are still collected remotely in the guide halls but this can now be done by several teammates using synchronised iPods and iPhones.