CERN, Meyrin, Switzerland
IAP, Frankfurt am Main, Germany
CERN, Meyrin, Switzerland
CERN, Meyrin, Switzerland
CERN, Meyrin, Switzerland
THBP58
CERN, Meyrin, Switzerland
| Paper | Title | Page |
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| MOA1I1 | Beam Performance with the LHC Injectors Upgrade | 1 |
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| The LHC Injectors Upgrade (LIU) project was put in place between 2010 and 2021 to increase the intensity and brightness in the LHC injectors to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2040). During the 2019-2020 CERN accelerators shutdown, extensive hardware modifications were implemented in the entire LHC proton and ion injection chains, involving the new Linac4, the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS), the Super Proton Synchrotron (SPS) and the ion PS injectors, i.e. the Linac3 and the Low Energy Ion Ring (LEIR). Since 2021, beams have been recommissioned throughout the injectors’ chain and the beam parameters are being gradually ramped up to meet the LIU specifications using new beam dynamics solutions adapted to the upgraded accelerators. This paper focuses on the proton beams and describes the current state of the art. | ||
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Slides MOA1I1 [10.002 MB] | |
| DOI • | reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA1I1 | |
| About • | Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 18 October 2023 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
| TUC3I2 | Shaping High Brightness and Fixed Target Beams with the CERN PSB Charge Exchange Injection | 135 |
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| CERN adopted the charge exchange injection technique for the first time in the PS Booster after Long Shutdown 2. This allowed to overcome space charge limitations, tailor high brightness beams for the LHC and deliver high intensity flux of protons to the fixed target experiments. Details on the concept, physics, hardware and diagnostic tools are presented while retracing the exciting steps of the successful commissioning period and the first years of operation with this system. A look to the future is taken by explaining the next stages to achieve the ambitious Luminosity targets foreseen for the HL-LHC era. | ||
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Slides TUC3I2 [19.053 MB] | |
| DOI • | reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC3I2 | |
| About • | Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 24 October 2023 | |
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| THBP09 | Pushing High Intensity and High Brightness Limits in the CERN PSB after the LIU Upgrades | 458 |
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| After the successful completion of the LHC Injectors Upgrade (LIU) project, the CERN Proton Synchrotron Booster (PSB) has produced beams with up to two times higher brightness. However, the efforts to continuously improve the beam quality for the CERN physics experiments are ongoing. In particular, the high brightness LHC beams show non-Gaussian tails in the transverse profiles that can cause losses in the downstream machines, and even at LHC injection. As a result, alternative production schemes based on triple harmonic capture are being investigated in order to preserve brightness and reduce transverse tails at the same time. In addition, in view of a possible upgrade to the ISOLDE facility that would require approximately twice the number of protons per ring, the ultimate intensity reach of the PSB is explored. In this context, injection schemes using painting both transversely and longitudinally in order to mitigate the strong space charge effects are developed. | ||
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Poster THBP09 [0.751 MB] | |
| DOI • | reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP09 | |
| About • | Received ※ 28 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 20 October 2023 | |
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| THBP38 | Two-Dimensional Longitudinal Painting at Injection into the CERN PS Booster | 563 |
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| To inject highest beam intensities at the transfer from Linac4 into the four rings of the PS Booster (PSB) at CERN, protons must be accumulated during up to 148 turns in total. With the conventional, fixed chopping pattern this process results in an approximately rectangular distribution in the longitudinal phase space. As the bucket shape in the PSB does not correspond to this distribution, the process leads to longitudinal mismatch, contributing to emittance growth and reduced transmission. The field in the last accelerating cavity of Linac4 can be modulated, which leads to fine corrections of the extracted beam energy. At the same time, the chopping pattern can be varied. Combining both allows injecting a near uniform longitudinal distribution whose boundary corresponds to an iso-Hamiltonian contour of the RF bucket, hence significantly reducing mismatch. In an operational context, the longitudinal painting must be controlled in a way that allows easy intensity variation, and can even require different painting configurations for each of the four PSB rings. This contribution presents the first demonstration of longitudinal painting in the PSB, and its impact on beam performance. | ||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP38 | |
| About • | Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 24 October 2023 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
THBP58 |
Advancing Beam Energy Absorption in the Large Hadron Collider: Evolution of Beam Dumps Design and Operation From LHC Construction to High Luminosity LHC | |
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| Two 6-tonne beam dumps are employed to absorb the energy of the two Large Hadron Collider (LHC) intense 7 TeV/c proton beams. Originally designed to handle approximately 300 MJ of energy deposited per dump event, the capacity of these dumps has grown over the lifespan of the LHC due to upgrades aimed at enhancing the machine’s scientific potential. In the era of the High Luminosity LHC (HL-LHC), the dumps will need to withstand energy absorptions of up to 700 MJ per dump. Several upgrades and interventions, such as adjustments to the outer vessel and supporting structure as well as enhancements to online instrumentation, have been executed since the initial installation of the beam dumps. In addition, significant advancements in simulation techniques have been implemented to gain a deeper understanding of the intricate dynamics of high-energy beam absorption and the resulting thermo-mechanical repercussions. Lessons learnt have been acquired also thanks to a first-of-a-kind autopsy. This contribution will present a comprehensive overview of the design, operational experiences, and evolutionary journey of the main absorber within the Large Hadron Collider. | ||
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