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arXiv · 2408.01074

Design, development, and construction of the new beam stoppers for CERN's injector complex

D. Baillard·E. Grenier-Boley·M. Dole·F. Deslande·R. Froeschl·T. Lorenzon·P. Moyret·R. Peron·A. Pilan Zanoni·C. Sharp·M. Timmins·M. Calviani
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Abstract

Beam stoppers are installed in the transfer lines of the CERN accelerator complex; these components are used as part of the access safety system, which guarantees the safety of workers in the accelerators. They are designed to stop one or at most a few pulses of the beam, where "stop" means the partial or complete absorption of the primary beam in such a way that the remaining unabsorbed primary or secondary beam remains below a specified threshold, as defined by the needs of radiation protection. Prior to Long Shutdown 2 (LS2; 2018--2021), beam stoppers in the injector complex were dimensioned for beam-pulse energies between 9.0 and 30~kJ. The upgrade of the accelerator complex in the framework of the LHC Injectors Upgrade (LIU) project involves beam-pulse energies of up to 92.5~kJ, meaning that these beam stoppers are not able to fulfill the new functional specifications. To cope with the LIU beam parameters and fulfil requirements for safety, maintainability, efficiency, and reliability, a new generation of 28 beam stoppers has been designed, built, and installed. The aim of this paper is to demonstrate the requirements-driven design of these new beam stoppers, outlining the main requirements along with a description of the design and structural assessments. This document presents the implementation and integration of a standardized but adaptable design using a unique 564-mm-long stopper core with a CuCr1Zr absorber and an Inconel~718 diluter, taking into account radiological and infrastructure challenges. The installation process is also described, and the first operational feedback received since LS2 is presented.

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D. Baillard, E. Grenier-Boley, M. Dole, F. Deslande, R. Froeschl, T. Lorenzon, P. Moyret, R. Peron, A. Pilan Zanoni, C. Sharp, M. Timmins, M. Calviani. 2024-08-02. Design, development, and construction of the new beam stoppers for CERN's injector complex. https://arxiv.org/abs/2408.01074

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