Design and operation of the air-cooled beam dump for the extraction line of CERN's Proton Synchrotron Booster (PSB)

A new beam dump has been designed, built, installed and operated to withstand the future proton beam extracted from the Proton Synchrotron Booster (PSB) in the framework of the LHC Injector Upgrade (LIU) Project at CERN, consisting of up to 1E14 protons per pulse at 2 GeV, foreseen after the machine upgrades planned for CERN's Long Shutdown 2 (2019-2020). In order to be able to efficiently dissipate the heat deposited by the primary beam, the new dump was designed as a cylindrical block assembly, made out of a copper alloy and cooled by forced airflow. In order to determine the energy density distribution deposited by the beam in the dump, Monte Carlo simulations were performed using the FLUKA code, and thermo-mechanical analyses were carried out by importing the energy density into ANSYS. In addition, Computational Fluid Dynamics (CFD) simulations of the airflow were performed in order to accurately estimate the heat transfer convection coefficient on the surface of the dump. This paper describes the design process, highlights the constraints and challenges of integrating a new dump for increased beam power into the existing facility and provides data on the operation of the dump

Energy deposition studies for the Upgrade II of LHCb at the CERN Large Hadron Collider

The Upgrade II of the LHCb experiment is proposed to be installed during the CERN Long Shutdown 4, aiming to operate LHCb at 1.5x$10^{34}cm^{-2}s^{-1}$ that is 75 times its design luminosity and reaching an integrated luminosity of about $400 fb^{-1}$ by the end of the High Luminosity LHC era. This increase of the data sample at LHCb is an unprecedented opportunity for heavy flavour physics measurements. A first upgrade of LHCb, completed in 2022, has already implemented important changes of the LHCb detector and, for the Upgrade II, further detector improvements are being considered. Such a luminosity increase will have an impact not only on the LHCb detector but also on the LHC magnets, cryogenics and electronic equipment placed in the IR8. In fact, the LHCb experiment was conceived to work at a much lower luminosity than ATLAS and CMS, implying minor requirements for protection of the LHC elements from the collision debris and therefore a different layout around the interaction point. The luminosity target proposed for the Upgrade II requires to review the layout of the entire insertion region in order to ensure safe operation of the LHC magnets and to mitigate the risk of failure of the electronic devices. The objective of this paper is to provide an overview of the implications of the Upgrade II of LHCb in the experimental cavern and in the tunnel with a focus on the LHCb detector, electronic devices and accelerator magnets

Implications of the Upgrade II of LHCb on the LHC Insertion Region 8: From Energy Deposition Studies to Mitigation Strategies

Starting from LHC Run3, a first upgrade of the LHCb experiment (Upgrade I) will enable oeration with a significantly increased instantaneous luminosity in the LHC Insertion Region 8 (IR8), up to 2 $\cdot$ 10$^{33}$ cm$^{-2}$ s$^{-1}$. Moreover, the proposed second upgrade of the LHCb experiment (Upgrade II) aims at increasing it by an extra factor 7.5 (up to 1.5 $\cdot$ 10$^{34}$ cm$^{-2}$ s$^{-1}$, as of Run 5) and collecting an integrated luminosity of 400fb$^{-1}$ by the end of Run 6. Such an ambitious goal poses challenges not only for the detector but also for the accelerator components. Monte Carlo simulations represent a valuable tool to predict the implications of the radiation impact on the machine, especially for future operational scenarios. A detailed IR8 model implemented by means of the FLUKA code is presented in this study. With such a model, we calculated the power density and dose distributions in the superconducting coils of the LHC final focusing quadrupoles (Q1-Q3) and separation dipole (D1) and we highlight a few critical issues calling for mitigation measures. Our study addresses also the recombination dipole (D2) and the suitability of the present TANb absorber, as well as the proton losses in the Dispersion Suppressor (DS) and their implications

Energy deposition studies in the LHCb insertion region from the validation to a step into the Hilumi challenge

The LHCb (Large Hadron Collider beauty) experiment at CERN aims at achieving a significantly higher luminosity than originally planned by means of two major upgrades: the Upgrade I that took place during the Long Shutdown 2 (LS2) and the Upgrade II foreseen for LS4. Such an increase in instantaneous and integrated luminosity with respect to the design values requires to reassess the radiation exposure of LHC magnets, cryogenics and electronic equipment placed in the Insertion Region 8 (IR8) around LHCb. Monte Carlo simulations are a powerful tool to understand and predict the interaction between particle showers and accelerator elements, especially in case of future scenarios. For this purpose, their validation through the comparison with available measurements is a relevant step. A detailed IR8 model, including the LHCb detector, has been implemented with the FLUKA code. The objective of this study is to evaluate radiation levels due to proton-proton collisions and benchmark the predicted dose values against Beam Loss Monitor (BLM) measurements performed in 2018. Finally, we comment on the upcoming LHC run (Run 3), featuring a first luminosity jump in LHCb.Comment: 13 pages, 17 figure

FLUKA simulations of the operational injection losses in TI8/IR8

This document describes the FLUKA studies of SPS-to-LHC injection losses. The TI8/IR8 model has been developed especially to understand and predict the effect of the proton impacts on the passive protection system of the SPS-to-LHC transfer line of beam 2. It provides a powerful tool for designing new loss mitigation solutions. The Run-2 commissioning data was instrumental in carry- ing out a benchmark study and building confidence into the model. The absolute comparison with experimental measurements, including a quench event, provides a better physical understanding of beam loss effects. The High-Luminosity LHC (HL-LHC) upgrade requires substantial changes in the full chain of the LHC injectors. In accordance with LHC Injectors Upgrade (LIU) project, a new transfer line protection system has been designed to attenuate HL-LHC beam to safe levels in case of mis-injection. The TI8 model was used to simulate loss effects in the new layout and to design a dedicated shielding system for the LHC-BLMs

Energy deposition studies for the LHCb insertion region of the CERN Large Hadron Collider

The LHCb (Large Hadron Collider beauty) experiment at CERN LHC aims at achieving a significantly higher luminosity than originally planned by means of two major upgrades: the Upgrade I that took place during the Long Shutdown 2 (LS2) and the Upgrade II proposed for LS4. Such an increase in instantaneous and integrated luminosity with respect to the design values requires to reassess the radiation exposure of LHC magnets, cryogenics, and electronic equipment placed in the insertion region 8 (IR8) around LHCb. Monte Carlo simulations are a powerful tool to understand and predict the interaction between particle showers and accelerator elements, especially in case of future scenarios. For this purpose, their validation through the comparison with available measurements is a relevant step. A detailed IR8 model, including the LHCb detector, has been implemented with the fluka code. The objective of this study is to evaluate radiation levels due to proton-proton collisions and benchmark the predicted dose values against beam loss monitor measurements performed in 2018. Finally, we comment on the upcoming LHC run (Run 3, from 2022 to 2025), featuring a first luminosity jump in LHCb

Comparison Between Run 2 TID Measurements and FLUKA Simulations in the CERN LHC Tunnel of the Atlas Insertion Region

In this paper we present a systematic benchmark between the simulated and the measured data for the radiation monitors useful for Radiation to Electronics (R2E) studies at the Large Hadron Collider (LHC) at CERN. For this purpose, the radiation levels in the main LHC tunnel on the right side of the Interaction Point 1 (ATLAS detector) are simulated using the FLUKA Monte Carlo code and compared against Total Ionising Dose (TID) measurements performed with the Beam Loss Monitoring (BLM) system, and 180 m of Distributed Optical Fibre Radiation Sensor (DOFRS). Considering the complexity and the scale of the simulations as well as the variety of the LHC operational parameters, we find a generally good agreement between measured and simulated radiation levels, typically within a factor of 2 or better

Energy deposition studies for the Upgrade II of LHCb at the CERN Large Hadron Collider

The Upgrade II of the LHCb experiment is proposed to be installed during the CERN Long Shutdown 4, aiming to operate LHCb at 1.5x$10^{34}cm^{-2}s^{-1}$ that is 75 times its design luminosity and reaching an integrated luminosity of about $400 fb^{-1}$ by the end of the High Luminosity LHC era. This increase of the data sample at LHCb is an unprecedented opportunity for heavy flavour physics measurements. A first upgrade of LHCb, completed in 2022, has already implemented important changes of the LHCb detector and, for the Upgrade II, further detector improvements are being considered. Such a luminosity increase will have an impact not only on the LHCb detector but also on the LHC magnets, cryogenics and electronic equipment placed in the IR8. In fact, the LHCb experiment was conceived to work at a much lower luminosity than ATLAS and CMS, implying minor requirements for protection of the LHC elements from the collision debris and therefore a different layout around the interaction point. The luminosity target proposed for the Upgrade II requires to review the layout of the entire insertion region in order to ensure safe operation of the LHC magnets and to mitigate the risk of failure of the electronic devices. The objective of this paper is to provide an overview of the implications of the Upgrade II of LHCb in the experimental cavern and in the tunnel with a focus on the LHCb detector, electronic devices and accelerator magnets

LHC Triplet Task Force Report

The excellent performance of the Large Hadron Collider (LHC) and the extension of Run 3 by one year have led to a significant increase of the expected integrated luminosity by the end of its operation and before the start of the High Luminosity LHC (HL-LHC), exceeding the design LHC integrated luminosity of 300 fb−1 for which the final focus region has been designed. The radiation dose accumulated by the components close to the Interaction Points (IPs) and resulting from the collision debris might approach or exceed the radiation limits that have guided the selection of the materials in the design of these components. A task force has been set-up to analyse the potential impact on machine performance and availability and identify mitigation measures. The results of the studies conducted by the Task Force are summarized in this report