| Paper | Title | Page |
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| MOPMF040 | Crossing Angle Anti-Leveling at the LHC in 2017 | 184 |
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| In 2017, LHC incorporated in operation an anti-leveling procedure of adapting in steps the crossing angle of the colliding beams to increase the integrated luminosity. In this paper, we present the Dynamic Aperture simulations that were employed to identify the operational margins, and therefore define the leveling steps. The results are complemented by observations from nominal operation and projections for the 2018 operation. Additional anti-leveling techniques, investigated in dedicated machine studies are also discussed | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF040 | |
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| MOPMF041 | Refining the HL-LHC Operational Settings with Inputs From Dynamic Aperture Simulations: A Progress Report | 188 |
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| Recent Dynamic Aperture (DA) simulations aimed at providing guidance for the latest updates of the operational scenario for the High Luminosity upgrade of the LHC. The impact of the increased chromaticity and octupole current has been assessed considering the latest updates of the optics. Additional means to improve the lifetime, such as tune optimization, have been identified and deployed. We also briefly discuss the impact of delivering high luminosity to the LHCb experiment. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF041 | |
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| MOPMF052 | Monitoring and Modeling of the LHC Luminosity Evolution in 2017 | 224 |
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| In 2017, the Large Hadron Collider (LHC) restarted operation at 6.5 TeV, after an extended end-of-the-year stop, scheduled to deliver 45/fb to the two general-purpose experiments. Continuous monitoring of the key beam parameters and machine configurations that impact the delivered luminosity was introduced, providing fast feedback to operations for further optimisation. The numerical model based on simulations and use of selected machine parameters to estimate the machine luminosity was further developed. The luminosity evolution and comparisons to the model predictions is presented in this paper. The impact of the dynamic variation of the crossing angle, which was incorporated into nominal LHC operation, is also discussed. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF052 | |
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| TUPAL064 | Extended-Domain Tune-Scans for the HL-LHC Dynamic Aperture in Presence of Beam-Beam Effects | 1163 |
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| We report simulations of the HL-LHC dynamic aperture (DA) at collision energy in the presence of beam-beam effects (weak-strong approximation) aiming to determine its dependence on the working point in tune space. Both linear domains working points are explored, spanning over (0.028 – 0.33) in horizontal tune, and two-dimensional ones which focus on more promising sub-regions near the diagonal. The range of parameters, such as bunch intensity and emittance, are chosen to correspond to the more important HL-LHC scenarios. A comparison with the LHC as built is also made. Direct benefit from these studies is the possible identification of working points alternative to the nominal one (in terms of dynamic aperture). They also help to understand the dependence of DA on particular resonance lines present in the vicinity of the footprint. In this work, the necessary resources were provided by the LHC@home project, based on the BOINC-SixTrack platform for distributed Computing. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL064 | |
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| THPAF059 | Ultra Compact Symplectic Scheme for Fast Multi-Particle Tracking | 3107 |
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| A versatile symplectic integration scheme has been developed in order to produce simplified versions of non linear lattices, preserving fundamental non-linear properties such as the detuning with amplitude and energy, in addition to the linear transport. The method has been applied to the LHC and benchmarked against tracking simulations with Sixtrack. This reduced lattice is made available as a refined replacement of the simple rotation matrix often used in multi-particle studies requiring a fast beam transport routine. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF059 | |
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| THPMK105 | PERLE - Lattice Design and Beam Dynamics Studies | 4556 |
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Funding: Work has been authored by Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 with the U.S. Department of Energy. PERLE (Powerful ERL for Experiments) is a novel ERL test facility, initially proposed to validate choices for a 60 GeV ERL foreseen in the design of the LHeC and the FCC-eh. Its main thrust is to probe high current, CW, multi-pass operation with superconducting cavities at 802 MHz (and perhaps testing other frequencies of interest). With very high virtual beam power (~ 10 MW), PERLE offers an opportunity for controllable study of every beam dynamic effect of interest in the next generation of ERL design; becoming a ‘stepping stone' between present state-of-art 1 MW ERLs and future 100 MW scale applications. PERLE design features Flexible Momentum Compaction lattice architecture for six vertically stacked return arcs and a high-current, 6 MeV, photo-injector. With only one pair of 4 cavity cryomodules, 400 MeV beam energy can be reached in 3 re-circulation passes, with beam currents in excess of 15 mA. The beam is decelerated in 3 consecutive passes back to the injection energy, transferring virtually stored energy back to the RF. This unique facility will serve as a test-bed for high current ERL technologies, as well as a user facility in low energy electron and photon physics. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK105 | |
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