Design and behaviour of the Large Hadron Collider external beam dumps capable of receiving 539 MJ/dump

Two 6 t beam dumps, made of a graphite core encapsulated in a stainless steel vessel, are used to absorb the energy of the two Large Hadron Collider (LHC) intense proton beams during operation of the accelerator. Operational issues started to appear in 2015 during LHC Run 2 (2014–2018) as a consequence of the progressive increase of the LHC beam kinetic energy, necessitating technical interventions in the highly radioactive areas around the dumps. Nitrogen gas leaks appeared after highly energetic beam impacts and instrumentation measurements indicated an initially unforeseen movement of the dumps. A computer modelling analysis campaign was launched to understand the origin of these issues, including both Monte Carlo simulations to model the proton beam interaction as well as advanced thermo-mechanical analyses. The main findings were that the amount of instantaneous energy deposited in the dump vessel leads to a strong dynamic response of the whole dump and high accelerations (above 200 g). Based on these findings, an upgraded design, including a new support system and beam windows, was implemented to ensure the dumps' compatibility with the more intense beams foreseen during LHC Run 3 (2022–2025) of 539 MJ per beam. In this paper an integral overview of the operational behaviour of the dumps and the upgraded configurations are discussed.Two 6-t beam dumps, made of a graphite core encapsulated in a stainless steel vessel, are used to absorb the energy of the two Large Hadron Collider (LHC) intense proton beams during operation of the accelerator. Operational issues started to appear in 2015 during LHC Run 2 (2014-2018) as a consequence of the progressive increase of the LHC beam kinetic energy, necessitating technical interventions in the highly radioactive areas around the dumps. Nitrogen gas leaks appeared after highly energetic beam impacts and instrumentation measurements indicated an initially unforeseen movement of the dumps. A computer modelling analysis campaign was launched to understand the origin of these issues, including both Monte Carlo simulations to model the proton beam interaction as well as advanced thermo-mechanical analyses. The main findings were that the amount of instantaneous energy deposited in the dump vessel leads to a strong dynamic response of the whole dump and high accelerations (above 2000g). Based on these findings, an upgraded design, including a new support system and beam windows, was implemented to ensure the dumps' compatibility with the more intense beams foreseen during LHC Run 3 (2022-2025) of 539 MJ per beam. In this paper an integral overview of the operational behaviour of the dumps and the upgraded configurations are discussed

SPS Beam Dump Facility - Comprehensive Design Study

The proposed Beam Dump Facility (BDF) is foreseen to be located in the North Area of the Super Proton Synchrotron (SPS). It is designed to be able to serve both beam-dump-like and fixed-target experiments. The SPS and the new facility would offer unique possibilities to enter a new era of exploration at the intensity frontier. Possible options include searches for very weakly interacting particles predicted by Hidden Sector models, and flavour physics measurements. Following the first evaluation of the BDF in 2014–2016, CERN management launched a Comprehensive Design Study over three years for the BDF. The BDF study team has executed an in-depth feasibility study of proton delivery to target, the target complex, and the underground experimental area, including prototyping of key subsystems and evaluations of radiological aspects and safety. A first iteration of detailed integration and civil engineering studies has been performed to produce a realistic schedule and cost. This document gives a detailed overview of the proposed facility together with the results of the in-depth studies, and draws up a road map and project plan for a three years Technical Design Report phase and a five–six years construction phase.The proposed Beam Dump Facility (BDF) is foreseen to be located in the North Area of the Super Proton Synchrotron (SPS). It is designed to be able to serve both beam-dump-like and fixed-target experiments. The SPS and the new facility would offer unique possibilities to enter a new era of exploration at the intensity frontier. Possible options include searches for very weakly interacting particles predicted by Hidden Sector models, and flavour physics measurements. Following the first evaluation of the BDF in 2014–2016, CERN management launched a Comprehensive Design Study over three years for the BDF. The BDF study team has executed an in-depth feasibility study of proton delivery to target, the target complex, and the underground experimental area, including prototyping of key subsystems and evaluations of radiological aspects and safety. A first iteration of detailed integration and civil engineering studies has been performed to produce a realistic schedule and cost. This document gives a detailed overview of the proposed facility together with the results of the in-depth studies, and draws up a road map and project plan for a three years Technical Design Report phase and a five–six years construction phase