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The ECN3 Beam Delivery Task Force was mandated by the PBC Study Group to assess the technical feasibility of increasing the proton beam intensity to the ECN3 hall of the North Area to satisfy the demands of a compelling set of PBC experimental physics proposals. This report summarises the findings of the Task Force that converge on a technically feasible solution with an implementation timeline that could exploit and build upon the investment already foreseen as part of Phase 1 of the NA-CONS project, and take the SPS complex into a new intensity frontier for Fixed Target physics in Run4.

In the framework of the Physics Beyond Colliders (PBC) study, a future high intensity facility at the existing ECN3 experimental hall of the North Area (NA) complex is under study. A task force is investigating ECN3 intensity upgrade scenarios concerning beam delivery and related infrastructure, considering solutions compatible with consolidation plans and post-LS3 experimental scenarios. As input to this study group, the sharing scenarios for the amount of protons on target (PoT) delivered to such a future high intensity fixed-target facility and the existing North Area experiments are presented in this report. Based on demonstrated Super Proton Synchrotron (SPS) performance for CERN Neutrinos to Gran Sasso (CNGS) and the recent SPS performance for fixed target beams following the successful completion of the LHC Injectors Upgrade (LIU) project, the expected proton sharing between the TCC2 targets and ECN3 is estimated. AWAKE and HiRadMat are taken into account in the future supercycle composition while the maximum possible power dissipation of the SPS magnets is respected. In the note it is also assumed that measures will be taken to address beam loss and activation at extraction and transfer compatibly with the transmission efficiency presented here. Finally, also considerations on power consumption are made for the different operational scenarios.

Resonant slow extraction from synchrotrons aims at providing constant intensity spills over timescales much longer than the revolution period of the machine. However, the extracted intensity is undesirably modulated by noise on the machine’s power converters with a frequency range of between 50 Hz and a few kHz. The impact of power converter noise can be suppressed by exploiting a Radio Frequency (RF) technique known as empty bucket channelling, which increases the speed at which particles cross the tune resonance boundary. In this contribution the implementation of empty bucket channelling in the CERN Proton Synchrotron (PS) is described via simulation and measurement. The technique was tested with both a resonant RF cavity and an inductive Finemet cavity, which can produce non-sinusoidal waveforms, to significantly reduce the low frequency noise observed on the extracted spill., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

ELENA is a small synchrotron ring that decelerates antiprotons down to a kinetic energy of 100 keV. With an experimental complex capable of housing up to 9 different experiments operating simultaneously, the transfer line design needed to be highly flexible. The low energy of the beam transported allowed the exploitation of electrostatic devices instead of magnets, to simplify design, production and operation. This contribution presents the systematic characterisation of the beam optics at the different experimental handover locations during beam commissioning using H⁻ ions from an external source, as well as the performance of the lines in operation with antiprotons. Finally, the effect of stray fields created by the experimental setup will be presented and compared with the first measurements., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

At the CERN Super Proton Synchrotron (SPS) the proton beam is supplied to the fixed target experiments in the North Area facility (NA) via a slow extraction process, taking place at 400 GeV. The monitoring of the spill quality during the extraction, lasting 4.8 seconds with the present SPS setup, is of high interest for minimising beam losses and providing the users with uniform proton-on-target rates. The monitor development challenges include the need for detecting, sampling, processing and publishing the data at rates ranging from few hundred Hz to support the present operation to several hundreds of MHz to serve future experiments proposed within the Physics Beyond Collider (PBC) programme. This paper will give an overview of the ongoing studies for optimizing the existing monitors performances and of the R dedicated to future developments. Different techniques are being explored, from Secondary Emission Monitors to Optical Transition Radiation (OTR), Gas Scintillation and Cherenkov detectors. Expected ultimate limitations from the various methods will be presented, together with 2022 experimental results, for example with a recently refurbished OTR detector., Proceedings of the 11th International Beam Instrumentation Conference, IBIC2022, Kraków, Poland

The CHARM High-energy Ions for Micro Electronics Reliability Assurance (CHIMERA) working group at CERN is investigating the feasibility of delivering high energy ion beams to the CHARM facility for the study of radiation effects to electronics components engineered to operate in harsh radiation environments, such as space or high-energy accelerators. The Proton Synchrotron has the potential of delivering the required high energy and high-Z (in this case, Pb) ions for radiation tests over the relevant range of Linear Energy Transfer of ~ 10 - 40 MeV cm²/mg with a > 1 mm penetration depth in silicon, specifically for single event effect tests. This contribution summarises the working group’s progress in demonstrating the feasibility of variable energy slow extraction and over a wide range of intensities. The results of a dedicated 6 GeV/u Pb ion beam test are reported to understand the performance limitations of the beam instrumentation systems needed to characterise the beam in CHARM., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

To provide HL-LHC performance, the CERN LHC injector chain underwent a major upgrade during an almost 2-year-long shutdown. In the first half of 2021 the injectors were gradually re-started with the aim to reach at least pre-shutdown parameters for LHC as well as for fixed target beams. The strategy of the commissioning across the complex, a summary of the many challenges and finally the achievements will be presented. Several lessons were learned and have been integrated to define the strategy for the performance ramp-up over the coming years. Remaining limitations and prospects for LHC beam parameters at the exit of the LHC injector chain in the years to come will be discussed. Finally, the emerging need for improved operability of the CERN complex will be addressed, with a description of the first efforts to meet the availability and flexibility requirements of the HL-LHC era while at the same time maximizing fixed target physics output., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The CERN LHC injector chain underwent a major upgrade during the Long Shutdown 2 (LS2) in the framework of the LHC Injectors Upgrade (LIU) project. After 2 years of installation work, the Proton Synchrotron (PS) was restarted in 2021 with the goal to achieve pre-LS2 beam quality by the end of 2021. This contribution details the main beam commissioning milestones, encountered difficulties and lessons learned. The status of the fixed-target and LHC beams will be given and improvements in terms of performance, controls and tools described., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand