He4Ever for iOS devices

Before refilling a dewar by one of the liquefiers operated by the CEA and CNRS, one enters the weight of the dewar or the amount of litres stored in it. The weight of the empty dewar being known, the application calculates the corresponding amount of liquid helium or the weight of the dewar. Then, after the refill, the weight is measured again and the quantity of liquid helium is deduced.

The weight of each dewar is measured before being allocated to an instrument or a laboratory. Once back at the gas station, the weight is remeasured and the quantity of liquid helium used by the instrument team is deduced.

Gas counters are installed on the experimental areas of the instruments, the laboratories and the recovery room. Regularly, the values displayed by these counters are entered in this section. That allows to check if the amount of gas recovered on each instrument corresponds to the volume of helium vaporised in the cryostats. If not, either the gas counter is malfunctioning, either the gas was lost because of a leakage or a wrong operation of the equipment.

The helium gas recovered on the instruments and the laboratories is collected in a 20m3 balloon. When the balloon is filled, two tight compressors take the gas out from the balloon and compress it up to 200bar inside 10 racks of bottles. When a series of 3 racks is filled, the gas is transferred to one of the liquefaction rooms by pressure equilibrium (about 0.5km away from our recovery room). The starting and ending pressures and temperatures are entered in this section and the volume of gas transferred is calculated and normalised to a standard temperature of 20°C.

Every month, the amount of gas recovered at ILL is calculated and compared with the volume of liquid helium distributed. To perform this calculation, we enter the amount of gas presently stored in the racks.