Experimental Simulation of Helium Discharge into the LHC Tunnel

The LHC cryogenic system contains about 100 tons of liquid helium. The highest amount of helium is located in the magnet cold mass (about 58 tons @ 1.9 K, 0.13 MPa), in the QRL supply header C (about 26 tons @ 4.6 K, 0.36 MPa) and in the ring line (about 0.7 tons 290 K, 2 MPa). The rupture of header C is one of the failures leading to the worst scenario of helium discharge into the tunnel. To investigate the consequences of this failure an experiment has been performed. This paper presents the layout of the test set-up and compares the experimental results with calculated data.