Simulations of full impact of the Large Hadron Collider beam with a solid graphite target

Abstract

The Large Hadron Collider (LHC) will operate with 7 TeV/c protons with a luminosity of 10 34 cm 22 s 21 . This requires two beams, each with 2808 bunches. The nominal intensity per bunch is 1.15 Â 10 11 protons and the total energy stored in each beam is 362 MJ. In previous papers, the mechanisms causing equipment damage in case of a failure of the machine protection system was discussed, assuming that the entire beam is deflected onto a copper target. Another failure scenario is the deflection of beam, or part of it, into carbon material. Carbon collimators and beam absorbers are installed in many locations around the LHC close to the beam, since carbon is the material that is most suitable to absorb the beam energy without being damaged. In case of a failure, it is very likely that such absorbers are hit first, for example, when the beam is accidentally deflected. Some type of failures needs to be anticipated, such as accidental firing of injection and extraction kicker magnets leading to a wrong deflection of a few bunches. Protection of LHC equipment relies on the capture of wrongly deflected bunches with beam absorbers that are positioned close to the beam. For maximum robustness, the absorbers jaws are made out of carbon materials. It has been demonstrated experimentally and theoretically that carbon survives the impact of a few bunches expected for such failures. However, beam absorbers are not designed for major failures in the protection system, such as the beam dump kicker deflecting the entire beam by a wrong angle. Since beam absorbers are closest to the beam, it is likely that they are hit first in any case of accidental beam loss. In the present paper we present numerical simulations using carbon as target material in order to estimate the damage caused to carbon absorbers in case of major beam impact.

Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider

“…FLUKA: Energy deposition at solid density. BIG2: Hydrodynamic calculations along radius at one fixed point on axis [26] Hydrodynamic calculations in r-Z geometry, energy deposition in BIG2 normalized with axial line density (analytic approximation) [19] Hydrodynamic calculations along radius at one fixed point on axis [1] Hydrodynamic calculations in r-Z geometry, energy deposition in BIG2 normalized with axial line density (analytic approximation) [6] Hydrodynamic calculations in r-Z geometry, energy deposition in BIG2 normalized with axial line density (analytic approximation) [28] Hydrodynamic calculations in r-Z geometry running FLUKA and BIG2 codes iteratively [29] and (this paper, Sec. V)…”

“…Tungsten and copper targets were considered. In both cases the energy deposition calculated for solid density by FLUKA was used [28]. In the second stage, we studied the heating and the hydrodynamic behavior of a solid tungsten cylinder in the r-Z geometry, but still used the solid-density energy deposition data [32].…”

High Energy Density Physics with Heavy Ion Beams and related Interaction Phenomena

“…LHC is not intended for high energy density physics experiments, however in case of failure, beam tubes, magnets, absorbers and the beam dump will turn into matter under the conditions of high energy density. The experimental as well as theoretical and simulation tools available for high energy density physics are very well suited to help accelerator designers in damage assessment and prevention [22].…”

Dynamic Radiation Effects Induced by Short‐Pulsed GeV U‐Ion Beams in Graphite and h‐BN Targets

“…With a new generation of particle accelerators like the Facility for Antiproton and Ion Research (FAIR) or the High Luminosity LHC at CERN, unprecedented high beam intensities will be reached. Under conditions of short pulse duration, the impact of intense ion beams on intercepting devices such as production targets [1], collimators [2], or beam dumps might result in failure of these components. Experiments measuring pulsed-beam-induced effects were previously conducted at the HiRadMat beamline at CERN [3][4][5][6][7], at Brookhaven National Laboratory [8], and at SIS18 at GSI [9].…”