  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.
