Interaction of the CERN Large Hadron Collider (LHC) Beam with Solid Metallic Targets

The LHC will operate at an energy of 7 TeV with a luminosity of 1034cm_2s_1. This requires two beams, each with 2808 bunches. The nominal intensity per bunch is 1.1 · 1011 protons. The energy stored in each beam is about 350 MJ, sufficient to heat and melt 500 kg of copper. Protection of machine equipment in the presence of such powerful beams is essential [1]. In this paper a specific failure of the protection system is discussed, resulting in the full beam accidentally being directed towards the accelerator equipment [2]. We carried out two-dimensional hydrodynamic simulations of the heating of a solid copper block with a face area of 2 cm x 2 cm, which is irradiated by the LHC beam with nominal parameters. With the present simulations we estimate that after an impact of about 100 bunches the beam heated region has expanded drastically and the density in the inner 0.5 mm decreases by about a factor of 10. The bulk of the following beam will not be absorbed and continue to tunnel further and further into the target. The results will allow estimating the length of a sacrificial absorber presently under discussion. A very interesting ”spinoff” from this work would be the study of high-energy-density states of matter induced by the LHC beam, because a specific energy deposition of 200 kJ/g is achieved after 2.5 µs.